EarthEnergyEarthEnergySystems

Residential

A Buyer’s Guide

Natural ResourcesCanada

Ressources naturellesCanada

Residential Earth Energy Systems: A Buyer’s Guide

Important Note

The aim of this publication is to help readers with the decisionto purchase and install an Earth Energy System (EES). The subject iscomplex, and the decision depends on many variables. As a result,this guide cannot provide enough information to evaluate a potentialsystem fully, nor is it a “how-to” manual for the installation, operationand maintenance of a system. Prospective buyers should thus seek outqualified advice and assistance to supplement the informationprovided here. They should also contact local utility and governmentagencies to ensure that their new system will meet all relevantelectrical codes, as well as building and site regulations.

Natural Resources Canada assumes no liability for injury, propertydamage or loss suffered by anyone using the information contained inthis guide. It is distributed for information purposes only and does notreflect the views of the Government of Canada or constitute anendorsement of any commercial product or person.

All photographs in this guide are compliments of Ed Lohrenz of Ice Kube Systems, except for the photograph on page 20.

©Her Majesty the Queen in Right of Canada, 2002

ISBN 0-662-30980-4Cat. No. M92-236/2001E

Aussi disponible en français sous le titre : Les systèmes géothermiques résidentiels : Guide de l’acheteur

Recycled paper

The digital mosaic of Canada which appears on the cover of thispublication is produced by Natural Resources Canada (Canada Centrefor Remote Sensing), and is a composite of individual satellite images.The differences in the density of vegetation are illustrated throughshading.

HOW TO USE THIS GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1 INTRODUCTION TO EARTH ENERGY SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .What is Earth Energy? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .How Earth Energy Systems Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Earth Energy System Variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Benefits of Earth Energy Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Worksheet Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2 EARTH ENERGY SYSTEMS FOR A NEW HOME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Home Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .System Design for a New Home . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Distribution Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .The Cost of Owning an EES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3 EARTH ENERGY SYSTEMS FOR AN EXISTING HOME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Existing Site and Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .System Design for an Existing Home . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Possible Upgrades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Removal of Existing Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4 CONTRACTOR SELECTION, MAINTENANCE AND TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . .Choosing an Earth Energy Contractor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A Basic Contract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Maintenance and Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Servicing Requiring a Contractor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5 DO YOU NEED MORE INFORMATION? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

APPENDIX: INSTALLATION CHECKLIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GLOSSARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CONVERSION FACTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Table of Contents

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How to Use this Guide

Residential Earth Energy Systems:A Buyer’s Guide provideshomeowners with theinformation they need toplan for the purchase of anearth energy heat pump system ina new or existing home. You mayhave already read the companionbrochure An Introduction to EarthEnergy Systems.

Now you want to know moreabout this renewable and energy-efficient year-round climatecontrol system.

Section 1 is an introduction toEarth Energy Systems – what theyare, how they work, the differenttypes, the benefits they provideand how much earth energy theyneed to work. Whether you arebuying or building a new home,or planning to retrofit yourexisting home, you shouldread Section 1.

New home buyers shouldthen read Section 2. Here youwill read about how your housedesign affects an Earth EnergySystem. It also recommendssystem designs that workbest for your house type andcompares their typical operatingcosts to alternative heating andcooling systems.

Section 3 is for homeownerswho want to install an EarthEnergy System in their existinghome. The design and systemthat are right for the home youare living in now can be verydifferent from standard systems.Because of this, and to make theinstallation of your new system aseasy as possible for you and your

family, you need to plan. Thissection covers various waysyou can upgrade your heatingand cooling system, comparestheir operating costs and listsimportant steps you should takewhen servicing your system. Youwill also need to read certainparts of Section 2 that applyto your situation.

Section 4 is important forall readers – those buying orbuilding a new home, as well asthose retrofitting or renovatingan existing home. It providesguidance on selecting a contractorand what needs to be covered ina basic contract. It also coversservice and maintenance as wellas basic troubleshooting.

Section 5 provides additionalsources of information.

The Guide ends with a glossaryof terms used in the earthenergy industry (given initalics throughout the Guide,except for captions, like this:ground water), and an appendixcalled “Installation Checklist.”Give this checklist to yourcontractor, who should fillit out, sign it and return twocopies to you. A table ofconversion factors and a reader’ssurvey complete this guide.

iv

The industry also usesother terms to describe EarthEnergy Systems: they includeground- and water-sourceheat pumps, GeoExchange®,and geothermal heat pumps.

What isEarth Energy?

The sun has always providedheat for the earth. Its energywarms the earth directly, butalso indirectly. Its heat evaporateswater from the lakes and streams,which eventually falls back toearth and filters into the ground.A few metres of surface soilinsulate the earth and groundwater below. The warm earthand ground water below thesurface provide a free,renewable source of energyfor as long as the sun continuesto shine. The earth under anaverage suburban residentiallot can easily provide enoughfree energy to heat and cool thehome built on it.

The free energy has only tobe moved from the groundinto your home. This is doneby drawing ground waterdirectly from a well and usinga heat pump to extract heatfrom it. As well, a circuit ofunderground piping called aloop can be buried in the soiloutside the home throughwhich fluid – water or antifreeze –is pumped. The fluid, called theheat transfer fluid, absorbs theheat in the ground water or soiland transfers it to the heat pump.The heat absorbed by the fluidfrom the solar-heated ground isextracted from it by the heatpump, and the now-chilled fluidis circulated through a heatexchanger over and over again toextract more heat from the earth.

If your home is located neara suitable pond or lake, you can

use an Earth Energy System (EES)to draw on this excellent sourceof free energy.

Burying a loop in the groundaround your home is likeowning your own oil well, butinstead of pumping oil from anunderground pool and burningit to create heat (and greenhousegases), you tap into clean energythat will be there for as long asthere is a sun.

A well-designed ground loopwill not hurt the earth or plantsgrowing above it. There is novisible part to show that it isburied in your yard. If yoursystem uses ground water, it hasno effect on the water otherthan changing its temperatureby a few degrees. Finally, a well-

designed ground water systemwill not waste the water, but putit back into the ground by meansof a return well.

How Earth EnergySystems Work

The heat energy taken from theground by your EES is consideredlow-grade heat. In other words, itis not warm enough to heatyour home without beingconcentrated or upgradedsomehow. However, there isplenty of it – the averagetemperature of the ground justa few metres below the surfaceis similar to (or even higher than)the average annual outdoor airtemperature. For example, inToronto, the average annual air

1

1 Introduction to Earth Energy Systems

Components of a typical Earth Energy System.

Runouts (Headers)

Ground Loop

Distribution System

Heat PumpPump

temperature is about 8.9°C, butthe average ground temperatureis 10.1°C. It is important to notethat this ground temperature is10.1°C on the hottest day ofsummer as well as on the coldestday of winter. That is why someof the first humans lived in caves– the caves would protect themfrom the temperature extremesof winter and summer. That isalso why an EES works soefficiently – it uses a constant,relatively warm source (ground orwater) from which to draw energy.

Basic Componentsof an EES

The figure on page 1 illustratesa typical EES. It is made upof three main parts: a loop, theheat pump and the distributionsystem. The following sectiondescribes some of the variousloop designs, heat pumps anddistribution systems commonlyused in a Canadian EES.

The loop is built from plasticpipe which is buried in theground outside your homeeither in a horizontal trench(horizontal loop) or through holesdrilled in the earth (vertical loop).The loop may also be laid on thebottom of a nearby lake or pond(lake loop or pond loop). Your EEScirculates liquid (the heat transferfluid) through the loop and tothe heat pump located inside thehome. The heat pump chills theliquid and distributes the heatcollected from it throughoutthe home. The chilled liquid ispumped back into the loop and,because it is colder than theground, is able to draw more

heat from the surrounding soil.These loops are often referredto collectively as a closed loop,as the same liquid circulatesthrough the closed system overand over again.

Another way is to pump groundwater or well water directlythrough the heat pump. An EESthat uses ground water is oftenreferred to as an open-loop system.The heat pump cools the wellwater, which is usually returnedto the ground in a return well. Torun an open-loop EES, you needtwo reliable wells with water thatcontains few dissolved mineralsthat can cause scale build-up orrust over the long term, as it ispumped through the heat pump’sheat exchanger.

In both cases, a pump circulatesliquid through the loop and theheat pump. The heat pump chills(or collects the heat stored in) the

liquid when it is being used as asource of heat, and circulates itback through the loop to pick upmore heat. A system for a largehome will require a larger heatpump and ground loop, with acirculation pump to match.

After the EES has taken the heatenergy from the ground loop andupgraded it to a temperatureusable in your home, it deliversthe heat evenly to all parts of thebuilding through a distributionsystem. It can use either air orwater to move the heat from theheat pump into the home. Forcedair is the most common distri-bution system in most parts ofCanada, although a hot-water orhydronic system can also be used.

Forced-Air Systems

A heat pump in a forced-air EESuses a heat exchanger to take theheat energy from the refrigerantto heat the air that is blown overit. The air is directed throughducts to the different rooms inthe home, as with any forced-airfossil fuel or electric furnace. Theadvantages of a forced-air EES areas follows:

• it can distribute fresh, outsideair throughout the home;

• it can air-condition the home(by taking the heat from the airin your home and transferringit to the ground loop) as well asheat it; and

• it can filter the air in yourhome as it circulates throughthe system.

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A coiled loop can be installed in theground or in a pond or lake.

An EES is designed to raise theheat of the air flowing throughthe heat pump by between 10and 15°C; fossil fuel or electricfurnaces are designed to raise itby 20 to 30°C. That differencemeans an EES must move moreair through the home todistribute the same amount ofheat as a conventional furnace.So to design an efficient, quietforced-air EES, the contractordesigning the ductwork musttake into account the largeramount of air to be moved.The ductwork should also haveacoustic insulation installed insidethe plenum and the first fewmetres of duct, as well as a flexibleconnection between the heatpump and the main ductto ensure quiet operation.

Hydronic (Hot-Water)Heating Systems

As we said earlier, a heat pumpcan heat either air or water. Thelatter type distributes the heat bymeans of a hydronic (or hot-water)heating system. If you choose itfor your home, keep in mindthat currently available heatpumps can heat water to nomore than about 50°C.

This limits your choices forequipment to distribute theheat to your home. Hot-waterbaseboard radiators are designedto operate with water heated toat least 65 to 70°C; they are lesseffective when the water is notas warm. As a result, you willneed larger radiators – or moreof them – to distribute the

same amount of heat. Or youcan reduce the heat loss fromyour home by installing moreinsulation, so you need less heat.

You can also install radiant floor,or in-floor, heating systems. Theseare becoming more commonbecause they can increasecomfort and improve systemefficiency. Again, you must makesure that your radiant floor heatingsystem is designed to operatewithin the temperaturecapabilities of your EES.

The temperature differencebetween the ground loop andthe hot water distribution systemdepends on the efficiency of theEES; the greater the difference,the less efficient the system.Typically, an EES will extractheat from the earth at about0°C. If a radiant floor heatingsystem requires a temperatureof 50°C to heat your home, theheat pump will produce about2.5 units of heat for every unitof electricity used to operatethe system. If the system can bedesigned to operate with waterat 40°C, it will produce 3.1units of heat for every unit ofelectricity used to operate it. Inother words, it will be about 25percent more efficient.

Think about it this way – ifyou have hot spring water toheat your home, you do notneed a heat pump. The hot springis a totally free, 100 percent-efficient source of energy. Butif the temperature of the waterfrom the well needs to be raised5°C to be high enough to heatyour home, you need some

3

In-floor hydronic systems are primarily used for heating.

Heat pumpexchangesheat fromwater

Fluid or liquid from ground loop

Warm waterheats radiantfloors

additional energy. If it has to beraised 20°C, you need even moreenergy. The greater thetemperature difference, thegreater the additionalenergy need.

If you are thinking of installinga radiant floor heating system inyour home, you should tell theperson designing it that you areplanning to use an EES. Makesure you take the followingfactors into account:

• placing your floor pipe 20 cm(rather than 30 cm) apartreduces the water temperaturerequired to heat your homeby 4 to 5°C and increasesthe efficiency of your EESby about 10 percent;

• laying your floor heating pipein concrete or Gypcrete ratherthan using aluminum reflectiveplates with the pipe reduces therequired temperature by 12 to15°C, increasing the efficiencyof your EES by 25 to 30 percent;

• suspending pipe in the joistspace under a floor meansthat you will need temperatureshigher than what your EES canproduce, unless the heat loss inthe space is very low;

• placing insulation under a slab-on-grade floor or under abasement floor reduces heatloss to the ground below; and

• installing a control system thatlowers the water temperaturepumped through the floor asthe outdoor temperature risesincreases the efficiency of theEES. This type of control iscommonly called an outdoorreset control.

Earth EnergySystem Variations

Overview

EESs, by definition, use the earthas their energy source. As notedearlier, there are basically twoways to move energy from theground and into your home –an open loop or well-water system,or a closed loop.

In a closed-loop system, a loop isburied in the earth around thehome, or laid in a nearby lakeor pond. Virtually all loops builttoday use high-density polyethylene(HDPE) pipe. This type of pipewas designed to be buried in theground; it is also used for smallnatural gas pipelines or waterlines. Joints are made by fusingor melting the pipe and fittingstogether, which makes a nearlyleak-proof connection.Mechanical joints are not usedin the ground. A loop made out ofHDPE can last 50 years or more.

A mixture of antifreeze andwater is circulated continuouslythrough the loop and heat pump,transferring heat from or to thesoil respectively, as heating orair conditioning is needed. In aclosed-loop system, the fluid nevercomes in contact with the soil.It is sealed inside the loop andheat pump.

In an open-loop system, groundwater is drawn up from a welland through the heat pump, thentypically pumped back into areturn well. New water is alwaysbeing pumped through thesystem when it is in operation.

It is called an open-loop systembecause the ground water is opento the environment.

Closed Loops

Closed loops can have manyconfigurations. There are threebasic types: vertical, horizontaland lake (or pond). The loop typeand configuration most suitablefor your home depend on thesize of your property, your futureplans for it, its soil, and evenyour contractor’s excavationequipment. Most often, the loopconfiguration is selected on thebasis of cost. If the loop isdesigned and installed properly,by taking into account theheating and cooling requirementsof the home, one type of loop willoperate with the same efficiencyas another, and provide years offree, renewable energy.

Canadian Standards AssociationInternational (CSA) and theindustry have developedstandards for EES installation.In addition, most heat pumpmanufacturers have developedguidelines or proprietary softwarefor their products to ensure thatEESs using them are designedand installed correctly. Mostprovide training for contractorsthat install their equipment aswell as technical support fortheir dealers. As a homeownerconsidering the installation ofan EES, ask your contractor forproof of training, experienceand competence of its staff inloop design and installation.

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Horizontal Loops

As the name implies, these loopsare buried horizontally, usuallyat a depth of about 2 to 2.5 m,although it can vary from 1.5 to3 m or more. Usually trenches areexcavated with a backhoe; a chaintrencher can be used in some soiltypes. Fill can sometimes be usedto cover a loop in a low-lying areaof the property. The trench canbe from 1 to 3 m wide. Four oreven six pipes can be laid at thebottom of a wide trench, whilesome loop designs allow twolayers of pipe to be stacked ina trench at different levels.Loop configurations mayeven use a “slinky” or coiledconfiguration that concentratesadditional pipe in a trench. Manydifferent configurations havebeen tested and approved. Makesure you ask your contractor forreferences. Contractors can oftenshow you photographs of loopsthey have installed.

The area you need to install ahorizontal loop depends on theheating and cooling loads ofyour home, the depth at whichthe loop is to be buried, the soiland how much moisture itcontains, the climate, theefficiency of the heat pumpand the configuration of theloop. The average 150-m2 homeneeds an area of between 300 and700 m2. Your contractor will usecomputer software or loop designguidelines provided by the heatpump manufacturer to determinethe size and configuration ofyour earth loop.

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Horizontal ground loops can both heat and cool your home. They are buried underground.

Coiled or “slinky” loop.

Vertical Loops

Vertical loops are made out ofHDPE pipe, which is inserted intoholes drilled in the soil. Typically,these boreholes are 15–100 m deep,and 10–12 cm around. Twolengths of pipe are fused into a“U-bend” (two 90° elbows) andinserted into the borehole. Thesize of pipe used for the loopvaries, depending on the costof drilling and the depth of theborehole; 32 mm pipe is commonin some areas, 19 or 25 mm pipein others. After the pipe has beenplaced in the borehole, it is filledwith clay grout. Some contractorsadd sand, finely crushed stone orcement to the grout. This is toensure good contact with the soiland prevent surface water fromcontaminating the ground water.CSA standards specify that theborehole around the pipe is to befilled by means of a tremie line,or a pipe inserted to the bottomof the borehole and retracted as itis filled with grout. This process isdesigned to eliminate air pocketsaround the pipe and ensure goodcontact with the soil.

The main advantage of a verticalloop is that it can be installed ina much smaller area than ahorizontal loop. Four boreholesdrilled in an area of 9 m2 – whichfits easily into an average citybackyard – can provide all therenewable energy you need toheat an average 150-m2 home.

The cost of installing a verticalloop can vary greatly, with soilconditions the single mostimportant factor. Drilling intogranite requires much heavier,more costly equipment, and is

much more time-consuming thandrilling into soft clay. It is evenmore time-consuming when thesoil contains a mix of materials,such as layers of boulders, graveland sand. The installation of avertical loop in this type of soilis three to four times more costlythan that of a horizontal one. Inareas like southern Manitobaand Saskatchewan, however,where glacial Lake Agassiz hasleft 15–50 m of soft clay deposits,a vertical loop can be installed forabout the same cost as ahorizontal one.

The depth of borehole neededfor a vertical loop depends onthe same factors that determinethe land area required for ahorizontal one. The land area

needed for the vertical loop,however, depends on the depthto which the boreholes can bedrilled cost-effectively. Forexample, if an EES requires 180 m of borehole in total, andis to be installed where bedrockis found at 20 m, it would usuallybe cheaper to drill nine boreholesto a depth of 20 m than threeto a depth of 60 m. Nineboreholes would require an areaof about 150 m2, and three, anarea of about 60 m2.

Lake or Pond Loops

These types of loops can beinstalled very cost-effectivelyfor a home located near a lakeor pond. Many homes in

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Vertical ground loops are similar to horizontal loops except that they are placedvertically and use less ground area.

northern Ontario, for example,are within metres of a lake thatsoaks up the sun’s energy allsummer. The water temperature atthe bottom of an ice-covered lakeis about 4 to 5°C even during thecoldest blizzard. And in thesummer, the lake water can easilyabsorb the heat you are trying toexpel to cool your home. All youneed is a year-round minimumdepth of 2–2.5 m of water inwhich the loop can be protectedfrom wave action and ice pile-ups.

Unless you own the lake,however, you need permissionfrom the provincial government,and in some cases from theGovernment of Canada, toinstall a lake loop. Some juris-dictions do not allow them.Destruction of fish spawninggrounds, shoreline erosion,obstruction of traffic on navigablewaters and potential damage tothe environment concern severalgovernment departments. Insome jurisdictions, enough lakeloops have been installed thatpermission is simply a matter

of filling out forms. Some EEScontractors who specialize inlake loop installation handle allthe permission paperwork fortheir clients.

In the Prairies, farm ponds areoften excavated to provide waterfor irrigation or livestock. A 750–1000-m2 pond with a constantdepth of 2.5 m can do doubleduty as a clean source of energy.The oceans can also supply vastamounts of energy, but care mustbe taken to protect an ocean loopfrom tide and wave damage.Many homes on the West Coastalready benefit from free,renewable ocean energy.

Open Loops

Open loops, or ground water EESs,take heat from well water thatis pumped directly through theheat exchanger in a heat pump.The required flow of well wateris determined by the capacityof your heat pump. In the coldestpart of the winter, heating a

typical 150-m2 new home takes20 000–30 000 L of water perday, or a flow rate of 0.4–0.5 Lper second (a typical backyardpool contains about 60 000–70 000 L). A larger home willneed proportionally more water.You need a reliable well to supplythis volume of water. Typically,you will also need a second orreturn well to dispose of the waterby pumping it back into theground. Most provinces regulatethe use of wells, and can adviseyou on the use of well water forEES applications. For example,you must take care to avoidaffecting your neighbors’ wellswhen pumping continuously.Regulations on the use of wellwater as a heat source for anEES vary with each province.You should contact thedepartment with jurisdictionover ground water resources forthe regulations in your province.

To ensure that the well is capableof supplying the water on asustainable basis, and that thereturn well has the capacity toaccept the water after it hascirculated through the heat pump,you need to carry out a pump teston your wells. In some locations,the capacity of the aquifer is wellknown, and you can find out thecapacity of your new well withina few hours. In other areas, it willbe necessary to perform a test bymeasuring the drop in waterlevels at specified intervals whilethe well is pumped at a knownrate for as long as 24 hours.

As well water circulates throughthe heat pump, corrosive water candamage the heat exchanger over

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Lake loop systems (pond) can be used in either heating or cooling mode.

time; additionally, water with ahigh mineral content can causescale buildup. Most manufacturerscan supply heat pumps made outof resistant materials like cupro-nickel or stainless steel that aremore suitable for use in open-loopsystems. Manufacturers willspecify the quality of water thatis acceptable for their equipment.Again, you may need to haveyour water tested to ensure itfalls within the guidelines. Thedepartment that regulates thewater resources in your provincemay be able to advise you onwhere the water can be tested.

Mechanical equipment lastslonger if it does not have to startand stop repeatedly. Well pumpsare no exception. The contractorinstalling the well pump andpressure system must be told thatit will be used to supply water foran EES. For efficient operation,the pump design and horsepowermust be chosen to supply thecorrect amount of water. Biggeris not better. The water require-ments for the system, the heightthe water is lifted from the welland the piping from the well tothe house and to the return wellmust be taken into account. Toprevent the well pump from

short-cycling, you may needto install a larger pressure tank.These details can affect theoverall efficiency of your EESby as much as 25–30 percent.

The temperature of ground wateris very constant, ranging between5 and 12°C across Canada. Thetemperature of the fluid pumpedthrough a closed loop used in ahome normally drops to slightlybelow freezing during the winter.When well water is used as theenergy source during the winter,the heat pump produces moreheat and will be more efficient.However, since the water mustactually be lifted from the ground,sometimes as much as 15–30 m,you will need a more powerfulpump than the one required fora closed-loop system. In addition,the same pump often supplieswater for both the heat pumpand general household use. Thecost of operating the larger wellpump often offsets the efficiencyof running the EES with well

8

A drilling rig is used to install verticalboreholes.

Ground water systems (open loop) can both heat and cool your home, depending onyour needs.

Supply well

Dischargewell

water. Ask EES contractors in yourarea about their experience withopen-loop systems when decidingon the best option for your home.

Benefits of EarthEnergy Systems

Good for theEnvironment

More than two thirds of theenergy delivered to your home byan EES is renewable solar energystored in the ground. This is greatfor your wallet because it is freeenergy. It is also good for theenvironment because there arevirtually no toxic emissions. Eachkilowatt (kW) of electricity usedto operate an EES draws morethan 3 kW of free, renewableenergy from the ground.

A large part of the cost ofenergy supplied to your homeis the expense of getting it there.Electric transmission lines, gaslines and oil pipelines are costlyto build and require extensiverights-of-way. Oil is shipped intankers halfway around theworld so you can heat yourhome. Trucks delivering fuelto your home need fuel andmaintenance. Shipping energyto your home entails real costs.They include not only directexpenses, like building pipelinesand maintaining transmissionlines, but also indirect costs,like dealing with emergencies.The infrastructure needed totransport energy is large andexpensive – for you and theenvironment. With an EES, mostof the energy you need is movedless than a few hundred metresinto your home. The cost oftransporting earth energyinto your home is the costof running a circulating pump.

When a conventional air-conditioning system is installed ina home, refrigerant lines run fromthe outdoor condensing unit tothe coil in the furnace. EESs, onthe other hand, are assembledand tested under controlledconditions, so that a refrigerantleak is much less likely. Also,any leak from an EES wouldbe much smaller, as it usuallycontains just one half therefrigerant charge of a conventionalair-conditioning unit. And now,the first units using non-CFCrefrigerants are being produced,reducing potential damage tothe atmosphere even more.

Year-Round Comfort

People living in homes withan EES often say, “This homeis the most comfortable we’veever lived in.” There are severalreasons for this. The airtemperature produced by anEES is typically about 35°C.The air produced by a fossil fuelfurnace or electric furnace isoften heated to 50–60°C – muchwarmer than room temperature.This can create hot spots in aroom. Moving around the room,you can often feel temperaturedifferences of 3–4°C.

You may have lived in a homewhere you were often about toadjust the thermostat just beforethe furnace came on, and a fewminutes later had to take off yoursweater. This is caused byoversizing the conventional heatingsystem. Even on the coldest day,an oversized furnace may only runfor 15 minutes an hour, because itcan produce all the heat you need

9

When you are planning anyexcavation, you must makesure the site is surveyed andthat the location of anyother services, such aselectrical lines, gas lines,water lines, sewer lines,septic fields or undergroundstorage tanks, is determined.Also, when you are decidingwhere to install a loop onyour property, keep in mindthat heavy equipmentcannot operate underoverhead electrical lines.Wherever you install theground loop or water wellsand lines for an EES, theymust be added to your siteplan. This will avoid costlyfuture repairs. The CSAstandards stipulate thatthe homeowner must beprovided with a copy ofa drawing showing thelocation of a closed-loopsystem, and that a tracingwire or tracing tape must belaid in the ground aboveany closed-loop pipes to makefinding the system easier inthe future. In addition, thecontractor must keep a copyof your closed-loop layout forseven years. The Earth EnergySociety of Canada is planningto set up a database withcopies of the earth-looplayout on behalf of ownersand contractors who aremembers of the society.

by running only 25 percent of thetime. The thermostat is satisfiedquickly when the furnace is on,and may even overshoot thedesired temperature by a degreeor two, and then the temperaturedrops several degrees beforecoming on again. This happensbecause the cost of installing alarger furnace is almostinsignificant, so the “bigger isbetter” attitude often prevails. Ifthe heat loss of a home is reduced(by upgrading the insulation orwindows), the overheatingproblem is made worse.

The cost of installing a larger EES,however, makes it prohibitive tooversize a system. As a result, itruns almost continuously,maintaining very eventemperatures throughoutthe home. Several manufacturersbuild two-speed units with multi-speed fans. These matchthe heating and cooling loadsof your home virtually yearround. In spring and fall, whenyou do not need the full capacityof the system, the compressorand fan will operate at lowspeed, providing only as muchheating and air conditioning asyou need. As the days get colderin winter, or during very hotsummer days, the system willoperate at high speed.

Most EESs are installed withthermostats that switch fromheating to air conditioningautomatically. You will findthat, on days in the springand fall when you need heatin the morning and coolingin the afternoon, you aremore comfortable.

Operating Cost

As noted earlier, more than twothirds of the energy supplied byan EES is renewable energy takenfrom the ground. The other thirdcomes from the electricity usedto power the system. You onlypay for the electricity you useto operate your system. Theother two thirds is free.

How does the cost of heatingyour home with an EES compareto the cost of heating it withother fuel options? That dependson the cost of the fuel and onhow efficiently your furnace usesit. As a fossil fuel furnace sendsthe products of combustion (CO,CO2, SO2, NOx, etc.) up thechimney, some heat leaves thehouse as well. Older furnaceswith pilot lights burn some gascontinuously, even when your

home does not need heating.If you are using an old gas oroil furnace, you can be ventingas much as 35 to 40 percent ofthe fuel you have purchased upthe chimney. If the furnace isgreatly oversized, it may wasteeven more energy, because bythe time it reaches operatingefficiency, it has already satisfiedthe thermostat and shuts off.

Electric furnaces and electricbaseboard heaters do not requirea chimney. All the energy theygenerate stays in your home –even if the electric motordistributing air through yourhome is not very efficient. Anelectric furnace or baseboardsystem can therefore beconsidered 100-percent efficient.

An EES does not create anycombustion products. As with the

10

3000

2500

2000

1500

1000

500

0

Heat

Hot water

Basic Charge

Electric Gas Propaneor Oil

Earth Energy

This chart shows the energy cost of the home described on the following worksheetexample. When compared to electric heat and hot water systems, the EES reduces costsby $1,140, natural gas by $920, and propane by $1,930 annually.

Feel free to make copies of the worksheet to compare the efficiency of the EESto other fuels.

electric furnace, all the electricenergy used to run the compressor,the pump and the fan stays inthe house. But since the systemalso draws additional free energyfrom the ground, it can actuallyproduce more energy than youput into it. Because of this, an EEScan be considered to operate atmore than 100 percent efficiency.

The efficiency of a heating systemis measured as the Coefficient ofPerformance (COP). Measuringthe energy your EES produces,and dividing it by the energy youput into it (and pay for) gives youthe COP. For example, if youpurchase natural gas that could,if burned completely, produce100 units of heat, but 7 of thoseunits are lost up the chimney,the COP is as follows:

(100 - 7) ÷ 100 = 0.93

EESs intended for open-loopsystems have heating COP ratingsranging from 3.0 to 4.0. Forclosed-loop heating applicationsthe COP rating is between 2.5and 4.0. See the descriptionunder “Heat Pump Selection”on page 16 for additionalinformation on the COP.

The worksheets on the followingpages will help you estimate thecost of energy to heat your homeand to heat water for domesticconsumption. The worksheetallows you to calculate energycosts by taking into account

• the size of your home;

• the number of people inyour home using hot water;

• the fuels available in your area;

• their costs; and

• the efficiency of the heatingequipment you are considering.

The first worksheet is for a 165-m2 home. It comparesthe cost of energy if you use

• electricity at a cost of$0.06/kWh;

• natural gas at a cost of$0.42/m3;

• propane at a cost of $0.53/litre;

• an EES that uses electricity ata cost of $0.06/kWh;

• a conventional electric furnace;

• a mid-efficiency natural gasfurnace;

• a high-efficiency propanefurnace; and

• an EES with a COP of 3.2, whichis the minimum COP allowed inCanada for an open-loop system.

11

Worksheet Example

12

Estimated Heating Energy Usage in kWhEnter the heated area of your home (in square metres) in Column A in Row 1, 2 or 3 (whichever best describes your home).

Multiply the area (from Column A) by the kWh shown in Column B to calculate the kWh usage for heating your home.

Estimated Hot Water Energy Usage in kWhIn Column A, enter the number of people in your household in addition to yourself. Multiply the number of people by the number in Column B.

Cost of Heat and Hot Water Using ElectricityAsk your electrical utility for the cost of electricity per kWh. Enter it in Column C, Line 7.

Cost of Heat and Hot Water Using Natural GasDetermine in what units your utility sells natural gas, and what the Basic Utility Charge is. Enter this figure in the appropriate line in Column A.

Cost of Heat and Hot Water Using Propane or OilAsk your fuel supplier for the cost of propane or oil per litre, and if there is a separate delivery or tank rental charge. Enter in Column A.

Cost of Heat and Hot Water Using an Earth Energy SystemDetermine the COP of the EES you are considering from the manufacturer or your contractor. Enter this in Column C.

* Average consumption for residences in Canada

** The “Basic Utility Charge” or “Delivery Charge” is charged by most utilities for monthly service, whether the fuel is used or not. Since most homes will have electrical service for

lighting and other uses to which a basic utility charge would be applied, it should not be added to the energy cost of homes heated with Electric Heat or an Earth Energy System.

Older home – insulation etc. not upgraded

Average home

R-2000 certified home

First person in home

Number of additional people

Cost of Natural Gas (per cubic metre)

Cost of Natural Gas (per gigajoule or GJ)

Propane (cost per litre)

Oil (cost per litre)

Enter the COP of ONE of the gas furnaces shown in Column B in Column C

Old gas furnace with pilot light

Newer gas furnace with pilot light (before 1995)

Mid-efficiency gas furnace

High-efficiency gas furnace

Enter the COP of ONE of the gas furnaces shown in Column B in Column C

Old gas furnace with pilot light

Newer propane or oil furnace with pilot light (before 1995)

Mid-efficiency propane or oil furnace

High-efficiency propane or oil furnace

Add Lines 4 and 5 to determine the total kWh needed to heat water for a home like yours

Enter the cost of electricity per kWh and enter this in Line 7Multiply Line 1, 2 or 3 by Line 7 to determine the cost of heating your home using Electricity

Multiply Line 6 by Line 7 to determine the cost of heating water for your household using Electricity

Divide Line 10 or Line 11 by Line 12, 13, 14 or 15 to calculate the cost per kWh

Add Basic Utility Charge**

Multiply Line 1, 2, or 3 by Line 16 to determine the total cost of heating your home using Natural GasMultiply Line 6 by Line 16 to determine the cost of heating water for your household using Natural Gas

Divide Line 20 or Line 21 by Line 22, 23, 24 or 25 to calculate the cost per kWh

Add Fuel Delivery Charge**

Multiply Line 1, 2 or 3 by Line 26 to determine the total cost of heating your home using Propane or OilMultiply Line 6 by Line 26 to determine the total cost of heating water for your household using Propane or Oil

Enter the COP of the Earth Energy System in Line 30Divide the cost of electricity in Line 7 by the COP of the Earth Energy System in Line 30

Multiply the cost of electricity in Line 31 by 2

Multiply Line 1, 2 or 3 by Line 31 to calculate the cost of heating your home with an Earth Energy SystemMultiply Line 6 by Line 32 to find the cost of heating water for your household with an Earth Energy System

A

165

A1st person

3

A0.42

A0.53

x

x

x

x

x

÷

÷

÷

÷

=

=

=

=

=

=

=

=

=

123

456

789

1011

1213141516171819

2021

2223242526272829

3031323334

89

171819

272829

3334

B*

200

150

100

B1900

1250

B10.35

277.79

B0.65

0.76

0.83

0.93

B6.97

10.69

B0.65

0.76

0.83

0.93

C

24 750

C1900

3750

5650

C0.060

$1,485

$339

C0.041

C

0.83

0.049

$120

$1,213

$276

C0.076

C

0.93

0.082

$120

$2,030

$463

C3.20

0.019

0.038

$470

$215

$1,485$339

$120$1,213$276

$120$2,030$463

$470$215

Worksheet to Estimate Annual Cost of Heating your Home Using Different Fuels – Example

kWh

kWh

kWh

kWh

kWh

kWh

Worksheet

13

Estimated Heating Energy Usage in kWhEnter the heated area of your home (in square metres) in Column A in Row 1, 2 or 3 (whichever best describes your home).

Multiply the area (from Column A) by the kWh shown in Column B to calculate the kWh usage for heating your home.

Estimated Hot Water Energy Usage in kWhIn Column A, enter the number of people in your household in addition to yourself. Multiply the number of people by the number in Column B.

Cost of Heat and Hot Water Using ElectricityAsk your electrical utility for the cost of electricity per kWh. Enter it in Column C, Line 7.

Cost of Heat and Hot Water Using Natural GasDetermine in what units your utility sells natural gas, and what the Basic Utility Charge is. Enter this figure in the appropriate line in Column A.

Cost of Heat and Hot Water Using Propane or OilAsk your fuel supplier for the cost of propane or oil per litre, and if there is a separate delivery or tank rental charge. Enter in Column A.

Cost of Heat and Hot Water Using an Earth Energy SystemDetermine the COP of the EES you are considering from the manufacturer or your contractor. Enter this in Column C.

* Average consumption for residences in Canada

** The “Basic Utility Charge” or “Delivery Charge” is charged by most utilities for monthly service, whether the fuel is used or not. Since most homes will have electrical service for

lighting and other uses to which a basic utility charge would be applied, it should not be added to the energy cost of homes heated with Electric Heat or an Earth Energy System.

Older home – insulation etc. not upgraded

Average home

R-2000 certified home

First person in home

Number of additional people

Cost of Natural Gas (per cubic metre)

Cost of Natural Gas (per gigajoule or GJ)

Propane (cost per litre)

Oil (cost per litre)

Enter the COP of ONE of the gas furnaces shown in Column B in Column C

Old gas furnace with pilot light

Newer gas furnace with pilot light (before 1995)

Mid-efficiency gas furnace

High-efficiency gas furnace

Enter the COP of ONE of the gas furnaces shown in Column B in Column C

Old gas furnace with pilot light

Newer propane or oil furnace with pilot light (before 1995)

Mid-efficiency propane or oil furnace

High-efficiency propane or oil furnace

Add Lines 4 and 5 to determine the total kWh needed to heat water for a home like yours

Enter the cost of electricity per kWh and enter this in Line 7Multiply Line 1, 2 or 3 by Line 7 to determine the cost of heating your home using Electricity

Multiply Line 6 by Line 7 to determine the cost of heating water for your household using Electricity

Divide Line 10 or Line 11 by Line 12, 13, 14 or 15 to calculate the cost per kWh

Add Basic Utility Charge**

Multiply Line 1, 2, or 3 by Line 16 to determine the total cost of heating your home using Natural GasMultiply Line 6 by Line 16 to determine the cost of heating water for your household using Natural Gas

Divide Line 20 or Line 21 by Line 22, 23, 24 or 25 to calculate the cost per kWh

Add Fuel Delivery Charge**

Multiply Line 1, 2 or 3 by Line 26 to determine the total cost of heating your home using Propane or OilMultiply Line 6 by Line 26 to determine the total cost of heating water for your household using Propane or Oil

Enter the COP of the Earth Energy System in Line 30Divide the cost of electricity in Line 7 by the COP of the Earth Energy System in Line 30

Multiply the cost of electricity in Line 31 by 2

Multiply Line 1, 2 or 3 by Line 31 to calculate the cost of heating your home with an Earth Energy SystemMultiply Line 6 by Line 32 to find the cost of heating water for your household with an Earth Energy System

A

A1st person

A

A

x

x

x

x

x

÷

÷

÷

÷

=

=

=

=

=

=

=

=

=

123

456

789

1011

1213141516171819

2021

2223242526272829

3031323334

89

171819

272829

3334

B*

200

150

100

B1900

1250

B10.35

277.79

B0.65

0.76

0.83

0.93

B6.97

10.69

B0.65

0.76

0.83

0.93

C

C

C

C

C

C

C

C

Worksheet to Estimate Annual Cost of Heating your Home Using Different Fuels

kWh

kWh

kWh

kWh

kWh

kWh

Low Maintenanceand Long Service Life

The heat pump in an EES workslike a refrigerator. The heat ittakes from the earth is broughtinto your home in the sameway your fridge brings the heatfrom the food placed in it intoyour kitchen – by means of thecoil at the back of the fridge.The only significant difference,other than capacity, is theaddition of a reversing valve that

allows your EES to cool yourhome and send the heat outof your house and into the earth.The compressor of a heat pumpis similar to, but much largerthan, a fridge compressor. Theonly other moving parts are theblower motor and the pump tocirculate fluid through pipeburied in the ground. Unlike anair conditioner, the equipment islocated inside your home – notexposed to dust, rain, snow andextreme temperatures.

If the system (i.e., the earthloop and the distribution system)is designed to match the needsof your home, it will operatewith very little maintenance,much like your refrigerator.The only regular maintenanceyou will have to do is to makesure the air filter is clean (ifyou have a forced-air system).

Inspections to clean the duct-work and fan and check that theelectrical contacts are not worn

14

4000

3500

3000

2500

2000

1500

1000

500

0

Heat

Hot Water

Basic Charge

Electric Gas Propaneor Oil

Earth Energy

This graph can be used to compare the annual cost of heat and hot water for your home after you have completed the worksheet.

The cost of cooling a home can vary greatly depending on the direction its windows face, the lifestyle of the residents andother factors. Because of this, the cost of cooling is difficult to calculate accurately. In general, however, an EES is abouttwice as efficient as a conventional air-cooled air-conditioning system, and will reduce energy costs accordingly.

should be part of an annualservice contract. If you install anopen-loop or well-water system, theheat exchanger in the heat pumpmay require regular cleaning bya qualified service contractor.

Several studies have shown thatan EES lasts much longer than aconventional fossil fuel furnace andair-conditioning system, as the EESis not exposed to rain, snow andextreme outdoor temperaturechanges. The earth loop, ifinstalled to CSA standards, canbe expected to perform well for50 years or more.

Heating DomesticHot Water

After space heating and airconditioning, heating wateris the largest single energy userin most homes. Water-heatingcapability can be added to yourheat pump simply by including aheat exchanger into the refrigerantcircuit inside the heat pump.Most heat pump manufacturersoffer units with a desuperheater.Whenever the heat pumpcompressor is running to heator cool your home, water froma conventional electricwater heater is circulated throughthe desuperheater and heated bythe hot refrigerant. When the heatpump is not running, the electricheaters in the hot water tankheat the water. Depending onhot water use, a desuperheater canprovide from 30 to 60 percent ofthe hot water needed in theaverage home.

Some manufacturers have takenthis concept a step further byoffering heat pumps that canproduce all of the hot waterneeded on demand. These heatpumps are designed to switchautomatically from heating andcooling air (by means of a forced-air system) to heating water,which can be used for domesticuse or for a hydronic (hot-water)heating system. The initial costfor this type of unit is higher,but with a large demand forhot water, the extra cost can berecovered quickly. These unitsare ideal for

• homes with large families andlarge demands for domestic hotwater;

• homes with a hydronic heatdistribution system in one part ofthe home and a forced-air systemin others (e.g., radiant floor heatin the garage or basement andforced-air on the main level); and

• heating an outdoor swimmingpool during the summermonths.

15

Non-Intrusive and Quiet

EESs use the earth or groundwater to dissipate the heatfrom your home to cool it.Conventional (air-cooled)air conditioners or air-sourceheat pumps move the heatinside your home to theoutside. An EES replacesthe outdoor condensing unitsof a conventional system witha ground loop or well-watersystem that is buriedunderground. With an EES,the outdoor compressor, fannoise and space needed fora condensing unit areeliminated, leaving youwith a quieter, morepeaceful backyard.

Other Benefits

Because all of the mechanicalcomponents of an EES areinside, they are protectedfrom vandalism and theweather. EESs can be appliedto almost any house typeand location; the type ofsystem you choose dependson the availability of land orwater, soil conditions, localregulations and other factors.

2 Earth Energy Systems for a New Home

Home DesignConsiderations

Energy-Efficient HomeDesign

Your decision to install an EESin your new home is a majorstep toward making it one of themost energy-efficient homes inthe country. But your home isa system, and the EES is justone part of it. The other homedesign choices you make willaffect how much you pay foryour energy, your future energycosts and how comfortable youare in your home. These includethe following:

• the type and level of insulationin its walls, ceilings and floors;

• the type of windows you chooseand the direction they face;

• how airtight your house is;

• the ventilation system;

• the types of appliances andlighting; and

• the landscaping around yourhome.

There are many energy-savingoptions you can choose from.Natural Resources Canada offers awealth of information on how tomake your home more energyefficient; please consult theaddress or phone number at theback of this guide.

When you make your new homemore energy efficient, you alsoreduce the size and cost of the EESyou need. You can use a smaller,less costly heat pump, earth loopand distribution system.

Location of In-groundEquipment and Services

Make sure there is adequateclearance between the EESand other in-ground items likeswimming pools, wells and septicsystems. Allow enough space tomanoeuver the chain trencher,backhoe, drill rig or otherequipment needed to install theEES; the work should be doneso as to cause as little disturbanceas possible to existing pavements,walkways, easements and otherrights of access. Pipe locationsshould be drawn on a site planto reduce the risk of damage inthe future.

The loop should not cross otherunderground services (gas lines,water mains, sewers, buriedtelephone and electrical lines);also, you should make sure theyare protected from damage andfreezing both during installationand after. All installation shouldmeet the CSA standards.

System Designfor a New Home

Heat Pump Selection

How much heat does your homelose? Calculating its heat loss isthe foundation on which yourEES design is built. The care taken in the construction of your homedetermines how much heatescapes through the cracksaround its windows and doors,and how well its insulation isinstalled. The direction yourwindows face determines howmuch solar energy they let

into the house. The heat losscalculation, therefore, determinesthe size of EES you need.

Your contractor’s heat losscalculations should be basedon the CSA standards for EESinstallation. The contractorwill need a set of plans withthe dimensions and constructionof the walls, ceiling and floors,and the size and types ofwindows and doors as well asthe direction they face. Windsand trees (which may shade thewindows) also affect heat loss.To measure accurately howtightly the home is sealed, somecontractors will perform a blowerdoor test. The contractor shouldgive you a copy of the heat losscalculation.

The CSA requires an EES tohave the heating capacity tosupply at least 90 percent of thetotal heat required in your home

16

A backhoe is used to dig a horizontaltrench for laying a ground loop.

annually. Auxiliary heat (usuallyelectric elements installed insidethe heat pump or in the ductwork)can supply the rest of the heat.Factors that influence the heatingcapacity you need for your homeinclude the number of occupants,the appliances and lighting, thesolar gain through the windows,the quality of the constructionand the climate.

Why does the CSA recommendan EES capacity of 90 percent(not including auxiliary heat)?Because it takes all heat sourcesin your home into account.The lights in your home giveoff heat. So do your stove,fridge, television, computer andfreezer. The sun shining throughthe windows helps heat yourhome. Finally, the people (andpets) in it create a significantamount of heat as well. A heatloss calculation does not takethis so-called “internal heatgain” into account. That is whyan EES that produces 90 percentof the calculated heat loss ofyour home will normally provideall of the heat your family needs.And it will cost a bit less.

An auxiliary heater providesadditional heat on just thecoldest days (usually, electricheating elements are installedin the ductwork or built intothe heat pump). The few hoursthe electric heat is needed affectyour energy bills only slightly,but can reduce the cost ofinstalling an EES significantly.And because heating is moreimportant than cooling inmost of Canada, the lower air-conditioning capacity

of the system is acceptablefor most homes, and will performbetter than a larger system.

The performance of a heat pumpis rated for both heating andcooling efficiency. This is usuallyexpressed as the Coefficient ofPerformance, or COP. The COPin the heating mode is referredto as the COPh, and in the coolingmode as the COPc. You calculateit by dividing the heating orcooling capacity of the systemby the energy used to run it. Forexample, if the heating capacityof a system is 10.4 kW, and thepower needed to operate thecompressor, pump and blower is3.25 kW, the COPh is 10.4 ÷ 3.25= 3.2. Similarly, if the coolingcapacity is 10.55 kW (36 000Btu/h x 0.000293 = 10.55), andthe power needed is 2.51 kW,the COPh is 10.55 ÷ 2.51 = 4.2.(Note: Some manufacturers definethe air-conditioning efficiencyof their EES as its Energy EfficiencyRatio (EER). The EER, expressedin Btu/h per watt, can beconverted to COPc by dividingthe EER by 3.413.)

Air-conditioning efficiency canbe expressed in the same terms.You calculate the COPc bydividing the cooling capacityof the system by the energyinput. So if the cooling capacityof a system is 36 000 Btu/h(36 000 x 0.000293 = 10.55 kW),and the power needed to run thesystem is 2.29 kW, the COPc is10.55 ÷ 2.29 = 4.6.

The efficiency of an EES variesas the temperatures and flowsof the liquid and air pumped

through the heat pump change.Manufacturers publish theratings of their EES on thebasis of a specific set of standardconditions called the ISO 13256-1rating. The rating for a closed-loopsystem is called the Ground LoopHeat Pump (GLHP) rating; therating for an open-loop or ground-water system is called the GroundWater Heat Pump (GWHP) rating.When comparing quotations onequipment, make sure you arecomparing the equipment on thebasis of the same standard ratings.As with any system, however,your EES will only meet theperformance ratings if the wholesystem is designed and installedaccording to the manufacturer’sspecifications.

Loop Size:Is Bigger Better?

You can think of an earth loop as arechargeable battery permanentlyconnected to a battery charger.Heat energy is drawn from theloop, or “battery,” as it is neededin your home. If the battery islarge enough, it is easilyrecharged by the heat energyfrom the surrounding ground,sun, rain, heat expelled duringthe cooling of your home, andheat emanating from the earth’shot core. But if your loop batteryis continuously drawn downmore quickly than it can berecharged, it will be unable toprovide enough energy to runyour system. And there is noeasy way to recharge it quickly.

So the ground loop has to meet therequirements of your home. Someof the factors that will affect the

17

size of the ground loop you needinclude

• the heating and coolingrequirements of your home;

• the moisture content and typeof soil;

• the depth at which the loopis buried;

• the climate;

• the amount of snow coveringthe loop in winter; and

• the size of the buried pipesas well as the distancebetween them.

The larger the heating andcooling loads of your home,the larger the loop must be.Moist, dense soil conducts heatmore quickly than light, drysoil. Pipe that is buried deeperhas more soil to draw heat fromand will perform better. A climatewith long cold spells will requirea loop (“battery”) that can holdmore heat. Heavy snow coverinsulates the earth and helpsretain the earth’s heat. If earthloop pipes are buried fartherapart, they are recharged bya greater mass of soil.

A competent contractor willknow the soil conditions inyour area, and will design theearth loop on the basis of allthese factors. Some heat pumpmanufacturers provide contractorswith computer software to dothis. The CSA requires that aclosed loop be installed with aminimum length of HDPE on thebasis of the variables listed above.

Distribution Systems

The distribution system is animportant component of anEES. It must be designed tomatch the capacity of the heatpump. If it is inadequate, partsof your home may not be warmenough in winter, or cool enoughin summer. A poor distributionsystem will also place unnecessarystress on the heat pump,shortening its life and causingunnecessary service calls.

If you are installing an EES ina new home with a forced-air,or ductwork, distribution system,

it is crucial for the contractordesigning and installing it toknow the amount of air thatmust be moved through thesystem for proper operation.If the air flow is restrictedbecause the ductwork is toosmall, you will find that somerooms are not heated or cooledadequately; the system mayalso create air noise. You mayfind yourself making unnecessaryservice calls because the heatpump cannot distribute all ofthe heat produced. Finally, safetycontrols may shut the systemoff during summer or wintertemperature extremes.

18

Forced-air distribution system can both heat and cool your home, depending onthe season.

Heat pump

Fluid or liquid from ground loop

If you decide on a hydronicheating system, the contractorshould ensure an adequate freshair supply to all parts of your newhome. A heat recovery ventilator(HRV) with ductwork to eachroom can accomplish this effec-tively. Ventilation is especiallyimportant in new homes, as theyare typically built to be moreairtight than older homes.

Before you chose a contractor,ask detailed questions aboutthe design of the distributionsystem. How were the ductsizes determined? Do they ensureadequate airflow to each roomand for the system? How werethe pipe sizes calculated? The costof the distribution system can be asmuch as 15–25 percent of the costof the system. If it is made toosmall, the system may cost less toinstall, but will probably not heatand cool your home as quietly,efficiently or comfortably as alarger one would, and cost morein service calls over its lifetime.

Heat Recovery Ventilator

The energy crisis of the 1970sspurred a lot of research onreducing the energy requirementsin new homes. Home buildershave worked hard to makehouses more airtight. As a result,mechanical ventilation systemsare now installed to ensure freshair gets into new houses toreplace the air that used to enterold houses through cracks aroundthe windows, doors and joists inconcrete basements.

Ventilation can mean simplyflushing stale, humid air with

a fan and introducing fresh airwith a second fan, but in areaswith a cold climate (includingmost of Canada) this representsa major heat loss.

A heat recovery ventilator (HRV)reduces the heat lost throughventilation by recovering between60 and 80 percent of the heatfrom the exhaust air. This canby itself reduce the size of the EES(including the heat pump, the loopand the ductwork) enough tojustify the cost of the HRV.

By introducing fresh air intoyour new home, you will becutting down on many of thepollutants emitted by newbuilding materials, carpet andfurniture which can causeallergies and breathing problems.The fresh, dry air introduced bythe HRV also reduces humiditylevels in your home.

Air Filtration (forced-airdistribution system)

There are two reasons to filterthe air circulating through theheat pump and ductwork of yourhome. The first is to capture dustand pollen particles and keepthem from being distributedthroughout your home. Thesecond is to prevent the air coilin the heat pump from becomingclogged with dirt and losingefficiency. There are severaldifferent types of air filtersavailable, including standarddisposable fiberglass filters (10-percent efficient), pleatedfilters, washable electrostatic airfilters and electronic air filters(50-percent efficient).

Whichever type you have,make sure you change or cleanit regularly to maintain theefficiency of the heat pump.

Controls

Thermostat

A thermostat is simply a switchthat turns a heat pump on oroff according to the temperaturelevel in the house. Most heatpumps installed in Canadianhomes provide air conditioningas well as heating; many alsohave auxiliary heaters, usuallyelectric. There are a numberof thermostat models to choosefrom. They range from simpleunits that are switched fromheating to cooling manually todevices that can be programmedwith a variety of settings, andeven more sophisticated controlsystems that allow you to adjustthe temperature of your homeover the Internet. In addition,there are zone control systemsthat allow you to heat or cooldifferent areas of your hometo different temperatures.

EESs are normally matchedmuch more closely to the heatingrequirements of your home thanconventional heating systems. Asnoted above, the systems areoften slightly undersized anduse electric auxiliary heaters onthe coldest days. A programmablethermostat may actually use moreenergy here, because as thesystem is bringing thetemperature of the home upafter a set period, the electricauxiliary heater may come on.

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Humidifier

Humidity control is an importantfactor in maintaining comfort inyour home. Fresh air brought intoyour home in winter holds lessmoisture than the warm air inside.It can thus lower the relativehumidity in your home to an un-comfortable level. You may wantto consider adding a humidifier.

When you install a humidifierwith your EES, you should chooseone that does not need a bypassbetween the supply and returnair ducts.

The Cost ofOwning an EES

Operating andMaintenance Costs

More than two thirds of theenergy produced by an EES isfree energy drawn from theground. It is easy to see why theenergy costs can be much lowerwith an EES than with any otherfuel, including natural gas. Also,earth-based system maintenancecosts are generally lower thanthose for a conventional heatingand air-conditioning system. Thereare good reasons for this. Aconventional air-conditioning systemincludes an outdoor unit used toexpel heat from your home. Thisunit bears the brunt of the oftensevere Canadian weatherconditions that alternate betweensnow and ice in the winter, andheat and humidity in summer.It is also subject to the movementof the ground around your home.This can put stress on the

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A Case Study – ShadowRidge Estates, Greely,Ontario

Shadow Ridge Estates showswhy choosing an EES is amajor plus for both buildersand home buyers.

“I was originally drawn to thissystem because it is so energyefficient and environmentallyfriendly,” explains DonCardill, owner of DonwelConstruction. Mr. Cardillquickly found out thatoffering an EES that heats ahome in the winter and actsas an air-conditioning unitin the summer is a greatselling feature for newhome buyers. “We can offerour customers somethingnobody else does – and it’sat the same price,” he says.

Owners have found thatEESs are extremely efficientat cooling homes. “We cancool the main floor of ourhouse down in just one hour.

We couldn’t do that with ourold system,” says Bill Barnes,a 10-year resident of ShadowRidge Estates.

Adds Mr. Gallant, anotherhomeowner, “I really like thefact that there’s no big, noisyair-conditioning unit outsidemy house. This is just part ofthe furnace.”

The EESs at Shadow Ridgehave other uses. Some homesuse them for radiant floorheating, heating tubes inlaneways to melt snow in thewinter, hot water for outsidehot tubs and energy to heathot water.

The cost savings are alsoquite substantial. A 185.8-m2

(2000-sq.-ft.) home builtabove R-2000 standards atShadow Ridge Estates hadan air-conditioning cost ofless than $50 for the wholecooling season and a heatingcost of less than $300 for theentire winter.

Shadow Ridge Estates home with an Earth Energy System.

refrigeration lines. Air-source heatpumps are subject to even morestresses than air-conditioningunits because they are expectedto operate year-round.

The heat exchangers of fossilfuel furnaces are subjected totemperature extremes whenthey operate. They eventuallycrack from the expansion andcontraction of the metal.

The conditions under which anEES operates are much less severe.The temperatures of the heatsource and heat sink (the loop)are lower and more constantthan those in a conventionalair conditioner or air-source heatpump. The temperatures in theheat pump are certainly lessextreme than the flames of a fossilfuel furnace. This puts less stresson the equipment, and so resultsin less maintenance. The loopitself is subject only to the

relatively constant temperaturesof the earth. Again, very littlestress is placed on the pipe, whichis virtually maintenance-free.

Again, the air filter of an EESusing a forced-air system mustbe cleaned or changed regularly,as with any forced-air heatingequipment.

Purchase Costs

The cost of installing an EEScan vary significantly in differentparts of the country. Typically,the cost of the heat pump itselfis about the same as that of aconventional furnace and airconditioner. The cost of installingthe heat pump can actually besomewhat lower, as it eliminatesthe costs of gas line connections,the chimney and a pad for theinstallation of the outdoor air-conditioning unit.

The cost of installing theductwork for an EES shouldbe similar to the cost ofductwork for a conventionalsystem. The cost of installingthe distribution system for ahydronic system may be slightlyhigher than that of a gas boiler,however, because the lower watersupply temperatures from an EESmay require the installation ofmore floor heat pipe or a largerradiation system.

The major difference incost between an EES and aconventional heating and airconditioning system is the costof the earth loop. This can varysignificantly from one locationto another, as described under“Earth Energy System Variations”on page 4. The followingchart shows the variation incost of different types of earthloops in different situations.

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Open Loop

$1,000–5,000

$1,000–6,000

$1,000–7,000

Pond Loop

$1,200–1,800

$1,800–2,500

$2,400–3,600

VerticalLoop (rock)

$2,400–3,200

$3,500–4,500

$4,800–6,000

VerticalLoop (clay)

$1,400–1,800

$2,000–2,500

$2,800–3,600

HorizontalLoop

$1,200–1,600

$1,800–2,200

$2,400–3,200

120-m2 home – 8.8 kW(2.5 ton)

160-m2 home – 14 kW (4 ton)

240-m2 home – 17.6 kW(5 ton)

NOTE: The costs shown are average ground loop costs for the size of EES indicated and can vary significantly, depending on theparticular conditions at a specific site.

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The Payback

One of the questions people often ask is, “If I buy an EES, what’s the payback?” There are many factors thatcan influence the payback. We can illustrate it by looking at the following example.

Jim and Donna are planning a 160-m2 house on a large suburban lot. They want to heat their home asinexpensively as possible. Natural gas is not yet available, but there has been talk of extending the gas linespast their property in the next year or two. They are considering an electric furnace, a propane furnace thatcan be converted to natural gas in a year or two, and an EES. Here are the quotations for all three options.

The estimated annual fuel costs are as follows:

A simple payback is easy to calculate. Simply subtract the cost of installing one system from the cost ofinstalling the EES, and divide by the fuel cost savings. For example,

The simple payback is $6,900 ÷ ($1,727 - $680) = 6.6 years.

$5,900

$6,400

$12,800

Electric furnace and air conditioning

High-efficiency propane furnace and air conditioning

Earth Energy System

$12,800

$5,900

$6,900

Earth Energy System

Electric furnace and air conditioning

Difference in cost

Total

$1,727

$1,844

$1,098

$680

Hot Water

$400

$497

$309

$270

Cooling

$119

$119

$119

$54

Heating

$1,208

$1,228

$670

$356

Electric furnace

High-efficiency propane furnace

High-efficiency gas furnace

Earth Energy System

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The difference in annual energycosts more than makes up thedifference of the higher initialcost of installing the EES. Whenyou take into account yourmonthly mortgage payments andthe monthly energy costs of bothsystems, you end up with an extra$37 ($449 ÷ 12 months) in yourpocket every month.

Of course, when you takeinflation or rising fuel pricesinto account, your savings areeven higher.

A life-cycle cost calculation takesthe cash-flow analysis a few stepsfurther, by adding the cost ofinflation on fuel, the cost ofreplacing your equipment at theend of its expected life, the costof borrowing the money to

install the system and other costs.These costs are typically estimatedover a 20-year period and arerelatively complex to calculate.But the following points areworth noting:

• The estimated life expectancyof the heat pump in an EES isapproximately 18 to 20 years,or about the same as aconventional furnace. Aconventional air conditioneror air-source heat pump canbe expected to last only 12–15years, because the outdoor unitis exposed to the weather.

• The earth loop can be expectedto last 50–75 years. Even if theheat pump needs replacementafter 20 years, the earth loop canbe expected to last much longer.

• If the cash-flow analysis showsthat your annual savings are$449 per year now, inflation willincrease the value of the savingswith the fuel inflation rate.

• If you were to invest theannual energy cost savingsin an RRSP earning 8 percentinterest, assuming an inflationrate of 2.5 percent, the annualsavings would grow to be worthover $24,000.

• The cost of fossil fuels is likelyto rise more rapidly thanelectricity rates in the earlypart of the 21st century becauseof increasing demand as NorthAmerican utilities convert fromburning coal to natural gas.

A cash-flow analysis shows you your cash outlay each year for owning and operating a system. If you arefinancing the cost of your home over a 20-year period, the cost difference to install the heating and airconditioning system is financed as well. For example,

Total

$2,284

$1,888

$449

Annual Principaland Interest

(7.5%)

$557

$1,208

Energy Cost

$1,727

$680

Electric System

Earth Energy System

Annual cash-flow saving with an EES

3 Earth Energy Systems for an Existing Home

Existing Siteand Services

Access To Site

An EES draws heat from the earth.Burying a ground loop for an EESrequires excavation around yourhome. Other services are usuallyburied in the ground already,including electrical cables, waterlines, sewer lines, septic fields andgas lines, that must be avoidedwhen you dig. There may be treesand shrubs that you would prefernot to disturb. On a smallerproperty, it may be impossible toget to the best possible site withheavy equipment like a backhoeor large, truck-mounted drill rig.

Sometimes there are alternatives.Contractors in some areasspecialize in the installationof earth loops on smaller lots.In some areas, it may be possibleto drill boreholes deep enough tocause only minimal disturbanceto a yard, or drill the boreholeswith a compact drill rig thatcan reach the site easily. A chaintrencher may be small enoughto fit into the backyard.

Make sure you know the typeof equipment the contractoris planning to use, and thatboth you and the contractorunderstand exactly where the loopwill be located. Many contractorswill mark the location of the earthloop with small flags or spray-paint markers on the ground.Tell the contractor about anylandscaping features you wantto protect. Before work begins,answer the following questions:Who will be responsible for final

landscaping work after the loopis completed? Will the contractorbe installing the loop, or will thework be sub-contracted? If thework is done by a sub-contractor,will the contractor be at the sitewhen the loop is installed? Willthe contractor guarantee theinstallation?

Adequacy of ExistingElectrical System andDuctwork

One of the benefits of an EES isits low power demand. Althoughit is often possible to install asystem in an existing homewithout upgrading the electricalservice, you must verify that thisis the case. If you are replacingan electric heating system, yourexisting electric panel willprobably be adequate. If youare replacing a fossil fuel furnace,however, you may well need toupgrade your service to

accommodate an EES, especiallyif you include an electric auxiliaryheater in the system.

Most electric or fossil fuel furnacesdesigned for residential use in thepast were intended to raise thetemperature of the air circulatingthrough them by 20–30°C. Thiswas done to reduce the airflowneeded to deliver heat to yourhome and minimize the ductworksize (and cost). Heat pumps in anEES typically are designed to raisethe air temperature by only about10–15°C. Because of this, youhave to move more air throughyour ducts if your new EES is todeliver the same amount of heatto your home.

Your contractor may recommendchanging some of the ductworkin an existing home toaccommodate the greater airflow you need. This will makethe system more efficient andreduce potential air noiseproblems. The contractor alsoshould recommend lining thesupply air and return air plenumswith acoustic insulation, andinstalling flexible connections inthe plenums connecting the heatpump to the ductwork system.

Site Services

As noted above, you must do athorough check into the locationof underground services aroundyour home. In addition, youshould do a survey to find whereyour property lines are, as wellas the positioning of easementsand required property setbacks.Your neighbours’ domestic waterwells may be affected. Similarly,

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Installation of a ground loop for anexisting home.

your neighbours’ wells mayaffect the performance ofyour open-loop EES.

Effect on Landscaping

The installation of the earth loopfor an EES will always cause somedisturbance to the landscapingaround your home. A horizontalloop will require significantlymore excavation than othertypes of loops, although anyloop installation will require somedigging around your home. Therepairs to the landscaping taketime, because the earth takes timeto settle back into the trenches.The length of time depends tosome extent on the type of soilon your property. Heavy clay soilstend to take longer to settle thanlooser, sandier soil.

In some soil conditions, thecontractor may recommend thatthe dirt remain mounded over thetrench for several months, oreven for the winter. The dirt willsettle as the rain soaks the trenchover time or the spring runoffbreaks down the larger clumps ofearth. If the extra earth isremoved, there probably will besome settling, which will result ina dip in the lawn wherever thetrenching was done. The resultsare generally better if the earth isallowed to settle naturally.

You can speed up the soil settlingby compacting of the soil every10–20 cm as the trench isbackfilled, although the labourcost can be high. Soaking the soilin the trench can accelerate thesettling process as well.

Once the soil has settled, therewill be nothing on your lawn toshow that a ground loop is buriedon your property.

Effect on AdjoiningStructures

Make sure your EES is designedso as not to disturb trees, walls,overhead wires and otherlandscaping features. Allowspace for the trenching ordrilling equipment as well asthe excavated soil. No part ofyour system or the coil you digup should cross a property linewithout the written approval ofyour neighbour. Also, make sureyou avoid crossing otherunderground services, like gasand water mains, telephone lines,power cables, sewer lines anddrains, and protect them fromdamage or freezing. An earth loopmust never be placed under aseptic tank or cross the septicsystem’s drain. In general, EESpiping should be placed wellaway from other services to avoiddamage during repair operations.

When the earth loop installation iscomplete, the CSA standard statesthat you should make a mappinpointing its location. Thesimplest method of mappingthe earth loop is to measure eachsignificant point of the loop (suchas the boreholes and the end of atrench) from two separate,permanent landmarks. Forexample, you can plot thelocation of a borehole from twocorners of your home; this createsa triangle between the two pointsand the borehole, and makes iteasy to find later. A map like this

will be valuable when you (orpossibly a future owner) wantto make landscaping changes,such as installing a decorativefountain or planting a tree.The map should be placed inan envelope attached to the heatpump or some other safe place.If you are considering thepurchase of a home with an EESalready installed, ask for a mapor diagram of the loop system.

The CSA standard also states thata tracing wire or tape should belaid in the trench above the pipe,so the loop can be located with ametal detector. A wide foil tapecan also be laid in the trenchon top of the pipe, to show thatsomething is buried underneath.

System Design foran Existing Home

Optimum Size

The owner of an existinghome, especially an olderhome, generally does not havethe house plans showing thewall construction, ceilinginsulation and other detailsneeded to calculate heat lossaccurately. You will thereforeneed to measure and estimate

25

The heating and coolingcapacity of the EES installedin your home is the singlemost important factor thatwill ensure a comfortablehome, long-lastingequipment and anefficient system.

the insulation value of featuressuch as the walls, the ceilingand the windows. Thisinformation will be helpfulto the contractor preparing aquotation. Ideally, a drawingshowing the direction the housefaces, the wall dimensions,window sizes and types,insulation values and otherfeatures for each level providesenough information to calculatethe heat loss. Since the windaffects heat loss and trees mayaffect the cooling loads if theyshade the windows, informationabout wind patterns and treeson the property is helpful. Somecontractors will also perform ablower door test. The contractorshould provide a copy of theheat loss calculation to you.

To double-check the calculatedheat loss of the home, somecontractors will ask for theenergy consumption in yourhome for an entire year. Ifthe insulation has not beenupgraded recently, or youhave built additions, theannual energy consumptionfigures can be used to estimatethe heat loss of the home.

In an existing home with aductwork system, there is anadditional reason to install asystem that provides less heatthan the calculated heat loss.Older fossil fuel furnaces orelectric furnaces were designedto circulate less air than an EES.It may be difficult or impossibleto upgrade the ductwork to thelarger volume capacity requiredby an EES without creatingunnecessary air noise. Remember

– when you are designing anEES for your home, bigger isnot necessarily better.

Many of the principles that applyto the system design of an EESfor a new home, such as COPh,COPc, ratings for closed- and open-loop systems and heat loadcalculations, also apply to existinghomes – see “System Design for aNew Home” on page 16.

Alternatives forHomes Heated withHot Water or ElectricBaseboard Heaters

An EES can be installed in anexisting home with a hydronic(or hot-water) heating system, ora home with electric baseboardheaters. Here are some thingsyou should consider if you wantto install a hydronic heating system.

Hydronic Systems

There are several types ofresidential hydronic systems.They include the old, heavy cast-iron radiators; the more modern,compact baseboard radiators; andradiant floor heating. There arealso systems that use hot waterto transfer heat to a forced-airsystem by means of a fan coil unit.Each of them can be used withan EES, although there arepresently no heat pumps that canproduce water warmer than 50°C,so the heating capacity of thedistribution system may bereduced. Many existing hot-waterheating systems will not distributeenough heat to your home unlessused with water at a temperaturegreater than 65–70°C.

If you have recently upgradedthe insulation and airtightnessof your home, however, its heatloss may have been reducedenough to allow you to use awater temperature low enoughto install an EES.

Cast-Iron Radiators

These decorative heavy radiatorswere designed for use without aprotective cover. As they are oftenlocated where people could comeinto contact with them, thesystems were usually designedto operate at about 50–55°C. AnEES is capable of generating 50°Cand, with some upgrading of thewindows and insulation in thehome, should work satisfactorilywith these systems. The piping tothe radiators will almost certainlyneed upgrading, however.Contractors have successfullyused 12, 19 or 25 mm flexible“PEX” tubing to run new linesto the radiators.

Baseboard Radiators

Most baseboard radiator systemswere designed to be used with 60–70°C water. As a result, theyare not compatible with an EES.The heating capacity of abaseboard radiator drops by30–50 percent when suppliedwith water at 50°C. In mostsituations, it will be difficult tomake an EES work with baseboardradiators without installing manyadditional units.

In-Floor Heat

In-floor heating systems are oftendesigned for use with watertemperatures lower than ones

26

compatible with an EES. However,if the system in your home usespipe installed in the void betweenthe floor joists rather than inconcrete or with metal reflectorplates, it probably will need watertemperatures hotter than thoseproduced by an EES.

Fan Coil Units

The heating capacity of a fancoil unit is directly related tothe temperature of the watercirculated through it. You shouldhave the capacity of the heatingcoil tested to ensure it is able todistribute enough heat to yourhome with an EES.

Before deciding to use theexisting hot-water distributionsystem, the contractor shoulddetermine that the distributionsystem will heat your homeproperly at the lower EESwater temperatures.

Electric Baseboards

Electric baseboards use electricalenergy to heat the room in whichthey are located and do not use aheat distribution system. There aretwo options. The first is to builda distribution system into yourhome – either forced air orhydronic – and use the appropriateEES. The second is to use heatpumps designed to heat a smallspace without a distributionsystem. Several manufacturersbuild console-type heat pumps invarious sizes. They are designedto be mounted against a walland both heat and air-conditiona single room without adistribution system. They aretypically 120–130 cm in length,

60 cm in height, and about 25 cm deep. Electrical powersupply and piping from theground loop must be suppliedto the console unit. This optionmight be appropriate for placesimpossible to reach withductwork (e.g., a third-storeyloft in an older home).

Air Conditioning

Existing homes without a forced-air distribution system can bedifficult to air-condition. Sometypes of heat pumps, like water-water models, for example, areable to provide chilled water thatcan be used in air-conditioningsystems. However, most hydronicheating systems are not designedto provide cooling. When a cast-iron or baseboard radiator, or in-floor heating system, is cooled withchilled water, condensation formson the cold surface of the pipesthrough which the water iscirculated. Some types of fancoil units can be used for airconditioning through the useof chilled water, but thecondensation must be collectedin a condensate pan under thewater coil. Also, the pipes throughwhich the chilled water circulatesmust be insulated.

It might also be appropriate touse console-type heat pumps (seethe previous section “ElectricBaseboards”) to provide coolingin some areas of a home heatedwith a hydronic system.

Some manufacturers produceequipment that can heat waterfor use with a hydronic system andalso heat or chill air for use in a

forced-air system. With thisequipment, it may be possibleto add some ductwork to yourhome for air conditioning, whilekeeping your existing hydronicdistribution system to provide heat.

Possible Upgrades

Upgrading Air Filters

See page 19 for a discussionon air filters. Whatever yourfilter type, you must changeor clean it regularly to maintainthe efficiency of your heat pump.

Adding a HeatRecovery Ventilator

You can improve the indoor airquality of your home by addinga heat recovery ventilator (HRV).Adding an HRV is also a goodidea if you are improving thesealing and insulation of yourhome while installing an EES.A more airtight R-2000 home,for example, will take in less freshair and so justify the installationof a separate fresh-air distributionsystem incorporating an HRV. Thisdevice adds fresh air to the home,but preheats it with an air-to-airheat exchanger that transfers heatfrom an equivalent flow of airleaving the home. Thus theair balance in your home ismaintained, while you recoversome 60–80 percent of the heatenergy that would otherwise beexpelled from your home.

The installation of an HRV willincrease the energy consumptionof your home if it has no freshair system at all, because even

27

28

though the air is preheated bythe expelled air, the HRV cannotrecover all of the heat. Whencompared to a fresh air systemwith no heat recovery, however,an HRV saves you energy costsand reduces the load on yourheat pump. The device can beintegrated into your existingforced-air system or added as aseparate system to your home.

Controls

See pages 19–20 for a discussionon controls for an EES in a newhome. The same controls applyto an existing home, with somedifferences in the way you controlthe humidity.

If you are changing to an EESfrom a gas or oil furnace, youwill be less likely to need ahumidifier, as the dry outsideair being drawn in to meetthe combustion demands ofthe furnace will no longer bea problem.

If you plan to install an HRV,the amount of dry outside airentering the home increasesand a humidifier may becomenecessary. If you are installingan EES and planning to use yourexisting forced-air distributionsystem, it would be better toreplace the standard bypasshumidifier with a non-bypasstype. A bypass unit will lowerthe performance of the heat pumpand reduce the quantity of airdelivered to the registers. If youare keeping your current hydronic

system as your heating distributionsystem, a portable humidifier maybe an option, particularly if youare adding an HRV to the system.

Removal ofExisting Equipment

If your existing furnace will notbe left in as a backup system, youmust make sure that it is removedat the conclusion of the contract.Equally important, the gasline should be disconnectedand capped properly; similarly,the oil tank must be removedand the filler hole cemented.Also, be sure to cancel any fuelsupply or service contracts – oilhas sometimes been delivered toa house where a tank had beenrecently removed, but the fillline had not yet been pluggedor removed.

Choosing an EarthEnergy Contractor

The best way to ensure that youget an experienced and reliablecontractor is to obtain referencesfrom satisfied former clients. Ifyou cannot, contact the EarthEnergy Society of Canada listedon page 31. You may also wantto contact the Better BusinessBureau near you or the systemmanufacturer for a listof qualified installers. Contact atleast three of the recommendedcontractors and get writtenestimates for the work. Ifyou have access to the Internet,some keywords you might searchare “geothermal heat pumps,”“earth energy,” “ground-sourceheat pumps” and “geoexchange.”Some Web sites you might wantto visit are listed on page 31.

A Basic Contract

Once you have chosen yourcontractor, make sure that thecontract provides details oneach of the following:

• breakdown of the tasks;

• the work involved at each stage;

• a list of equipment;

• a breakdown of costs for thematerial and labour, and

• a payment schedule.

In addition, the contract shouldspecify who is responsible forrelandscaping the property andinternal refinishing, as the jobis not complete until this workis done. It should include thecalculation of the heating and

cooling load for the home, anyrequired changes or upgrades tothe ductwork, fans or filters andthe electrical system, as well asthe installation and startup ofthe EES. The refurbishment ordecommissioning and removalof existing equipment might alsobe included. The contract mustname the person responsible forapprovals and certifications forthe job and must clearly set outwarranty terms to allow a propercontract comparison. Most EESheat pump units are covered bya one-year warranty on parts andlabour and a five-year warrantyon the compressor. Make sure thatthe contractor fills out, signs andgives you two copies of theInstallation Checklist includedin the Appendix on page 32.Finally, make sure that thecontractor is adequately insuredfor the work – this means coverageof at least $1 million in damagesper major event (drilling boreholesor trenching, installing theheat pump unit or other event).

Maintenance andTroubleshooting

As with any mechanicalequipment, the unit willeventually not work properlyor stop altogether. Here are somethings you can check before youcall your service contractor.

✔ Check the air filter. If theenergy produced by a heatpump is not removed anddistributed to your homequickly enough, the pressurein the refrigerant system willshut the unit off automatically

before it gets damaged. If theair filter is clogged enoughto prevent adequate air flowthrough the heat pump, it alsowill shut down. Cleaning thefilter will restore the air flow.Never operate the unit withoutan air filter, as the manufac-turer may void the warranty.It also may be possible thatsome of the supply air orreturn air registers in thehome have been blocked off(for example, painters mayhave blocked the registers insome rooms while painting).

✔ Make sure thethermostat is set properly.If the thermostat setting ischanged accidentally, the unitmay not receive a signal toheat or cool your home. Somethermostats have a separateswitch that controls whetherthe system heats or air-conditions. Others may alsohave warning lights to indicatea problem with the system.

✔ Check whether anydisconnect switchesor circuit breakers forthe heat pump are on.Heat pumps with an electricauxiliary heater usually haveseparate circuit breakers forthe heat pump compressorand the auxiliary heater. If thecircuit breaker trips when youswitch it on again, contactyour contractor or servicecompany immediately.

✔ Check the power supplyto the circulating pump.The pump on most EESs witha closed loop takes its power

29

4 Contractor Selection, Maintenance and Troubleshooting

from the heat pump itself,although it can sometimeshave a separate power supply.The well pump for an open-loop (ground-water) systemwill probably have its ownpower supply. Make sure it ison. The controls for the wellpump may require repair.If so, contact the contractorthat installed the well pumpand pressure system.

✔ Check your owner’smanual. The manufacturerof your heat pump may haverecommendations specific tothe equipment installed inyour home that may correcta problem with your system.

When the unit is air-conditioningyour home, condensation formson the air coil inside the heatpump. A condensate drain (typicallyclear plastic tubing) is normallyinstalled to drain the water fromthe heat pump to a floor drain,sump pit or drain with a trap.If an appropriate drain is notlocated near the heat pump, apump may have to be installedto pump the condensate to adrain. In time, dust and dirt mayplug the condensate drain, causinga pan under the air coil to fill andspill over onto the floor. Cleaningthe drain and the hose willnormally solve this problem.

Servicing Requiringa Contractor

Occasionally, your EES mayrequire servicing. Specializedtraining and diagnostic toolsmay be needed to ensure theproper operation of your system.Call your service contractor if

• the circuit breaker for the heatpump or circulating pump tripsrepeatedly after resetting;

• the heat pump does not heat orair-condition adequately afteryou have checked that the airfilter is clean and the thermostatsettings are correct;

• you hear a “gurgling” noisefrom the piping connectingyour heat pump to the earthloop; or

• you hear grinding noisesfrom the pump circulatingfluid through your heat pump.

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5 Do You Need More Information?

31

Renewable and Electrical Energy Division Energy Resources BranchNatural Resources Canada 580 Booth Street, 17th FloorOttawa ON K1A 0E4Fax: (613) 995-0087

CANMET Energy Technology CentreNatural Resources Canada580 Booth Street, 13th FloorOttawa ON K1A 0E4Fax: (613) 996-9418Web Site: http://www.nrcan.gc.ca/es/etb

The Canadian Geo-Exchange CoalitionWeb site: http://www.geo-exchange.ca

To find out about manufacturers, dealers, distributorsor installers of EESs in your area, please contact

Earth Energy Society of Canada124 O’Connor Street, Suite 504Ottawa ON K1P 5M9Tel.: (613) 371-3372Fax: (613) 822-4987Web site: http://www.earthenergy.ca

We have free software to assist you!

Renewable energy technologies, such as an EES, can be a smart investment. RETScreen® International hasjust made it easier. RETScreen® International is a standardized renewable energy project analysis softwarethat will help you determine whether an EES is a good investment for you. The software uses Microsoft®

Excel spreadsheets, as well as a comprehensive user manual and supporting databases to help your evaluation.

The RETScreen® International software and user manual can be downloaded free of charge from the Web siteat http://retscreen.gc.ca. You may also contact Natural Resources Canada (NRCan) by phone at (450) 652-4621or by fax at (450) 652-5177.

To order additional copies of this publication and other publications on renewable energy and energyefficiency, please call our toll-free line at 1 800 387-2000. You can also get a copy of this publication byvisiting the Canadian Renewable Energy Network (CanREN) Web site at http://www.canren.gc.ca.

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(Two copies are to be provided to owner)

Owner’s Name _______________________________________________________ Date ___________________________Address ________________________________________________________________________________________________City/Province ____________________________ Postal Code________________ Phone _________________________

Contractor’s Name ___________________________________________________ Date ___________________________Address ________________________________________________________________________________________________City/Province ____________________________ Postal Code________________ Phone _________________________

System Type: ■■ Open-Loop ■■ Closed-Loop House Size _____________________Design Heat Load (Building) ___________________________________________ Design Method ________________Design Cooling Load __________________________________________________ Method _______________________Domestic Hot Water Load (met by system) _______________________________________________________________ Total Heating Load _____________________________________________________________________________________Type of Distribution System: ■■ Forced-Air ■■ HydronicHeat Pump Make______________________________________________________ Model/Serial No. _______________Heating Capacity: _____________________________________________________ Cooling Capacity _______________

Heat Exchanger Length, if Horizontal ____________________________________________________________________ Heat Exchanger Type, if Horizontal: ■■ Single-Pipe ■■ Two-Pipe

■■ Four-Pipe ■■ Other ______________________________________

Borehole Depth and Number, if Vertical __________________________________________________________________Heat Exchanger Sized According to ■■ Manufacturer ■■ Software ■■ Engineering Specifications

Backfill Materials, Horizontal Trenches ___________________________________________________________________Borehole Fill Material, If Vertical ________________________________________________________________________ Type Of Antifreeze/Inhibitors __________________________________________ Quantity ______________________Antifreeze Protection Level ____________________________________________ Loop Test Pressure ______________System Static Pressure __________________________________________________________________________________

Attach copy of the water well record or well pump test and include the number of and specifications of wells,intake and pumps.

Appendix: Installation Checklist

Entering Water Temperatures (EWT), check as appropriate Heating EWT: ■■ 0°C ■■ 10°C(Ref. CSA Standard C13256-1) Cooling EWT: ■■ 25°C ■■ 10°C

If Software Used, Name Program:

If a Closed-Loop System

If an Open-Loop System

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Markings/Instructions

■■ Supply and return valves marked accordingly.

■■ Submerged heat exchanger position marked at shoreline.

■■ Label at loop charging valve showing antifreeze type, concentration, contractor information.

■■ Owner given manufacturer documentation and warranty on system.

■■ Owner given site survey worksheet of installed system (including dimensions/locations of all piping,diameter, depths and lengths of loops, septic systems, water inlet lines, lot lines, etc.).

■■ Supply and return lines to be identified by marker at point of entry to water wells.

■■ Inform owner of possible effects on supply water well of open-loop system water quality, quantity, etc.

■■ Ensure water supply well is sealed in accordance with approved well construction practices.

■■ Ensure water well yields enough water to supply both domestic and heat pump requirements at timeof installation.

This installation was done in accordance with CSA-C448, Design and Installation of Earth Energy Systems, andcurrently applicable regulations.

Name (Please Print or Type) ________________________________

Signature ________________________________

Date ________________________________

If a Closed-Loop System

If an Open-Loop System

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Acoustic insulation: a sound-absorbent material installed insidethe plenum and ductwork toreduce noise created by forced-airheating and cooling equipment.

Air-conditioning/heatingsystem, Conventional: seeConventional system.

Air-to-air heat exchanger: seeHeat recovery ventilator (HRV).

Air coil: see Coil.

Antifreeze: a modifying agentadded to water in a closed-loopsystem to lower the temperatureat which the water freezes.

Aquifer: a rock or granular (sandor gravel) formation in whichwater can collect and throughwhich water can be transmitted;more fractured or porousformations can hold and transmitgreater quantities of water and soprovide a useful energy source foran EES (also see Ground water).

Auxiliary heat, heater: asecondary heat supply usedto supplement the main sourceof heat. In a residential system,electric heating elements aremost often used to supplementthe heat supplied by an EES.Most heat pump manufacturerscan install the auxiliary heatinside of the heat pump cabinet.

Backhoe: a mechanized, heavy,self-propelled digging implementto excavate earth during theinstallation of an EES loop.

Blower motor: an electricmotor used to turn the fan to

move air through the ductworkin a heating and cooling system.

Blower door test: a methodto measure how tightly a homeis sealed by increasing the airpressure inside a home inrelation to the outside.

Borehole: a vertical hole drilledin the earth to insert pipe totransfer heat from the soil.

Btu/h: British thermal units(Btu) per hour. One Btu is theamount of heat needed to raise by 1°F (0.56°C) the temperatureof one pound (0.45 kg) of waterat 39°F (3.9°C).

Bypass, Non-bypasshumidifier: see Humidifier.

Canadian StandardsAssociation International(CSA): a Canadian organizationthat sets standards for safety,energy performance andprocedures, including those for the installation of an EES.

Cash-flow analysis: a study ofthe economics of owning an EESthat takes into account the cost ofpurchasing the system (includinginterest paid on money borrowedto purchase it) and the cost ofenergy used to operate it.

CFC: a fluid used as a refrigerantin an EES; toxic if released intothe air. Non-toxic refrigerantsare now being produced (alsosee Refrigerant).

Chain trencher: mechanicaltrench-excavating heavy equip-ment that can be used duringthe installation of an EES loop.

Circulation (or circulating)pump: in an EES, a device usedto pump liquid through theloop and heat pump. The liquidtransfers heat between theearth and the heat pump.

Closed loop: see Loop.

Coefficient of performance(heating) (COPh): a measureof the efficiency of a heatingappliance, calculated bydividing the heat outputby the energy input.

Coefficient of Performance(cooling) (COPc): a measure ofthe efficiency of an air-condition-ing appliance, calculated bydividing the cooling outputby the energy input.

Coil (Air, Water): the heatexchanger that transfers heatbetween the air and refrigerantis sometimes called an air coil,whereas the one transferring heatbetween the refrigerant and theliquid circulated through the loopis often referred to as a water coil.

Combustion, products of:toxic particles produced by theburning of fossil fuels like oil,natural gas, propane and coal;eliminated by the installationof an EES (also see Emissions;Greenhouse gases: CO, CO2,SO2, NOx; Global warming).

Compressor: a device used tocompress refrigerant gas in a heatpump. Compressing a gas raisesits temperature and makes itmore useable to heat either ahome or domestic hot water.

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Condensate drain: an openingthrough which water droplets(condensate) that form on anair coil in a heat pump while itis in air-conditioning mode, andcollected in a condensate pan,are drained to waste.

Condensing unit: part ofa conventional air conditioner;unnecessary if you install an EES.

Console-type heat pump: apump designed to heat or coolair without being connected toa distribution or duct system andused primarily for a single-roomapplication (also see Heat pump).

Conventional heating/air-conditioning system/furnace: a system using theprevalent fuels (fossil fuel, electricresistance, air-cooled condensingunits) to provide heating andcooling to most homes.

Cupro-nickel: a metal alloy,or mixture, of copper and nickel.

Desuperheater: a heatexchanger installed in a heatpump directly after the compressorand designed to remove a portionof the heat from hot, vapourizedrefrigerant; in an EES heat pump,it is typically intended to heatdomestic hot water.

Distribution system: a systemthat distributes the heated (orcooled) air (or water) suppliedby a heating system in a home.Ductwork is normally used in aforced-air system, and water pipingis used in a hydronic heating system.

Earth Energy Society ofCanada: an organization formed

by contractors, manufacturers anddesigners of EESs to promote theproper design and installation ofsystems in Canada.

Earth Energy System (EES):a system designed to transferheat to and/or from the soiland a building, consisting of aheat pump that is connected to aclosed or open loop, and a forced-airor hydronic heat distribution system.

Easement (also Right-of-way): the legal right to enter,or cross, another person’sproperty for the purpose ofaccess, usually by a utility likea hydro provider or pipeline.

EES: see Earth Energy System.

Electrical heating/air-conditioning system,Conventional: seeConventional system.

Emissions: toxic particlesproduced by the burning offossil fuels like oil, natural gas,propane and coal; eliminatedby the installation of an EES(also see Combustion, productsof; Greenhouse gases: CO, CO2,SO2, NOx; Global warming).

Energy Efficiency Ratio(EER): a measure of thecooling or air-conditioningefficiency of an appliance,calculated by dividing thecooling output in Btu/h bythe energy input in watts.

Expansion tank: acontainer connected to aliquid-filled system such asan earth loop or a radiant floorheat system, that allows for

expansion and contraction of thefluid with changes in temperature.

Fan coil unit: a water-to-airheat exchanger combined with afan designed to heat or cool airby using hot or chilled water asa source.

Flexible connections: bendableconnectors of ductwork or pipingdesigned to prevent the transferof vibration from heating or air-conditioning equipment such asa heat pump to the main ductworkor piping in the home.

Floor heating system: a heatdistribution system in which thefloor is warmed (usually bycirculating warm water throughpipes in the floor, or with electricelements built into the floorstructure). Heat is radiated to theroom by the entire floor surface.Water can be heated by any hot-water heating system. Also knownas in-floor or radiant floor heating.

Forced-air heating/air-conditioning systems,Conventional: seeConventional systems.

Fossil fuel: combustiblesubstance derived from thedecay of organic material overlong periods of time and underhigh pressure such as naturalgas, oil, propane or coal.

Global warming: increasein the temperature of the earth’soceans and atmosphere due tothe release of greenhouse gasessuch as carbon monoxide (CO),carbon dioxide (CO2), sulphurdioxide (SO2) and nitrous oxides(NOx) (also see Combustion,

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products of; Emissions; Green-house gases: CO, CO2, SO2, NOx).

Greenhouse gases: gasesreleased through combustionof fossil fuels releases gases likecarbon monoxide (CO), carbondioxide (CO2), sulphur dioxide(SO2) and nitrous oxides (NOx);commonly referred to as suchbecause they allow the sun’sradiation to pass through butblock the radiation of the earth’sheat back into space (also seeCombustion, products of;Emissions; Global warming).

Ground (or Earth) loop:see Loop.

Ground-Loop Heat Pump(GLHP): an alternative termfor a heat pump that extracts heatfrom the ground (also see EarthEnergy System).

Ground water: a water supplydrawn from an undergroundaquifer (also see Aquifer).

Ground-Water Heat Pump(GWHP): an alternative termfor a heat pump that extracts heatfrom an open well-water system.

Grout, grouting: the placementof grout in a borehole from thebottom up by means of a pipeor hose and pump during theinstallation of a vertical loop foran EES (also see Tremie line).

Gypcrete: the trade name for aconcrete mix used to cover pipein a radiant floor heating system.Its main purpose is to transmitheat away from warm watercirculated through the pipe to the air in the room.

HDPE: see High-densitypolyethylene.

Heat exchanger: a devicedesigned to transfer heat betweentwo different materials (hot andcold liquid, liquid and air, liquidand soil, or hot and cold air) whilemaintaining a physical separationbetween the two materials.

Heating/air-conditioningsystem, Conventional: seeConventional system.

Heat pump: a device at theheart of an EES designed toextract heat from a low-gradesource (like the earth) by wayof an open or closed loop andconcentrate it for use to heat aspace. It consists of a compressor,a blower motor and a circulatingpump. A reversing valve enablesit to switch functions to provideboth air conditioning and heatto a home. It may be eitherconsole-type or water-water.

Heat recovery ventilator(HRV): a heat exchanger designedto recover heat from air beingexhausted from the home andtransfer it to fresh air beingsupplied to the home. Typically60–75 percent of the heat fromthe exhaust air is recovered andtransferred to the fresh air supply(also see Air-to-air heat exchanger;Size, sizing).

Heat sink: an area where aheat pump transfers the heat ittakes from a “heat source.” In anEES, the soil is a heat sourcewhen a home is being heated,and a heat sink when a home isbeing cooled.

High-density polyethylene:a long-lasting synthetic materialused as a ground heat exchangerpiping material.

Horizontal loop: see Loop.

Hot spot: the area in a homewhere the high temperaturesproduced by a conventional systemfurnace make the air significantlywarmer than the surrounding airin the home, usually near a warmair register.

Hot-water heating system,conventional: see Conventionalsystem.

Humidifier (Bypass, Non-bypass): a bypass humidifiercirculates warmed air from thesupply air of a heating systemand circulates it through adampened material back to thereturn air of a forced-air heatingsystem. A non-bypass humidifierinjects a mist of water or steamdirectly into the heated air streamdistributing air to the home.

Hydronic heating/air-conditioning system,Conventional: see Conventionalsystem.

In-floor heating systems: seeFloor heating systems.

Infrastructure: permanentlarge-scale engineeringinstallations like roads,sewers and energy pipelines.

Joist: one of a series of paralleltimber or metal beams installedfrom wall to wall in a house tosupport the floor or ceiling.

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Lake loop: see Loop.

Life-cycle cost: similar to a cash-flow analysis used to calculatethe economics of owning an EES,the life-cycle cost analysis alsotakes into account the cost ofmaintaining and/or replacing theequipment as it deteriorates overtime; probably the most accuratemethod of determining the truecost of owning an EES.

Loop: a heat exchanger used totransfer heat between a heat pumpand the earth, using liquid as aheat transfer medium. Types ofloops used in an Earth EnergySystem include the following:

Open: designed to recover andreturn ground or surface waterwith a liquid-source heat pump;usually requires two wells –one from which to drawthe water (primary well)and a second to receive thecirculated water (return well).

Closed: a continuous, sealed,underground or submergedsystem, through which a heattransfer fluid (refrigerant) iscirculated.

Ground (also Earth):a sealed underground pipethrough which a heat-transferfluid is circulated to transferheat to and from the earth.

Horizontal: pipes that areburied on a plane parallelto the ground.

Lake (also Ocean, Pond):sealed pipes arranged in loopsand submerged in a lake(ocean or pond), through

which a refrigerant passes toabsorb or release heat from orinto the water.

Vertical: pipes that are buriedon a plane at 90 degrees tothe ground.

Low-grade heat: a source ofheat that is not hot enough toheat a living space by itself.

Non-bypass, Bypasshumidifier: see Humidifier.

Non-CFC refrigerant: see CFC,Refrigerant.

Ocean loop: see Loop.

Open loop: see Loop.

Outdoor reset control: seeReset control, outdoor.

Oversizing, oversized: selectinga heating or cooling system thatis too large for a home. Such asystem will run for only a shortperiod of time before the temper-ature of the home is satisfied,and not operate as efficiently asa system that is sized accurately,as most systems take severalminutes to reach peak operatingefficiency (also see Size, sizing).

Payback, simple: seeSimple payback.

PEX tubing: cross-linkedpolyethylene pipes designedto withstand temperatures greaterthan HDPE pipe; used for in-floor(also known as radiant floor)heating systems, domestic waterpiping systems and other types.

Plenum: an enclosed spaceinto which the air from forcedair heating or cooling equipmentis blown directly. The maindistribution ducts are connectedto the plenum to distribute theair throughout the home.

Pond loop: see Loop.

Pressure tank: part of awell pump, used to prevent short-cycling.

Products of combustion: see Combustion, products of.

Programmable thermostat:a device that controls the heatpump of an EES, which can be setelectronically to perform varioustasks (also see Thermostat).

Property setbacks: areas,usually along a property line, setaside by municipal or provinciallegislation for common serviceslike sidewalks.

Pump test: in an open-loopsystem, a verification that primaryand return wells can provide thevolume of water necessary tooperate an EES efficiently.

Radiant floor heatingsystems: see Floor heatingsystems.

Refrigerant: a fluid usedin a heat pump designed tocondense and vapourize atspecific temperatures andpressures to enable the transferof heat energy between twoheat exchangers (also see CFC).

Reset control, outdoor:a control used primarily with

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radiant floor heating systems thatis designed to raise and lower thetemperature of the water beingcirculated through the systemaccording to the outdoortemperature. During colderweather, hotter water is circulatedthrough the floor to convey moreheat to the space. As the outdoortemperature increases, less heatis needed and the temperatureof the water circulated throughthe floor can be decreased. Thisstrategy permits continuousoperation of the heating system,and increases both the levels ofcomfort in the space and theefficiency of the heating system.

Return well: a water well inan open-loop system designedto return water to an aquifer.

Reversing valve: a device usedto reverse the flow of refrigerant ina heat pump to enable it to heat aswell as air-condition a space.

Right-of-way: see Easement.

Setback period (on athermostat): the time duringwhich a thermostat is turneddown, such as during the night,to conserve energy. Programmablethermostats allows the user to setspecific temperatures for a homeduring different parts of the day.They can also be used to set ahigher temperature during warmweather to conserve energy whileair-conditioning a home.

Setbacks, property: seeProperty setbacks.

Short-cycling (of a wellpump): the continuous on-and-

off cycling of a well pump withtoo great a pumping capacity foran EES. Short-cycling when a heatpump is in operation can damagethe motor of a pump over thelong term by causing prematurewear of some components, anduses significantly more energythan a properly sized pump.

Simple payback: a roughmethod of determining theeconomics of installing one EESas opposed to another that canbe installed at a lower first cost.The simple payback of an EES iscalculated by dividing thedifference in cost between twosystems by the estimated savingsin energy costs. The cost ofmaintaining the system andreplacing the systems as theydeteriorate over a longer termis ignored in this calculation. Amore accurate method is the cash-flow analysis, which includes thecost of purchasing the system andthe energy cost, or the life-cyclecost analysis, which adds the costof replacing the equipment overthe longer term.

Size, sizing: calculating thecapacity of the heating andcooling system required onthe basis of an accurate heatloss and heat gain analysis ofthe home (also see Oversized,Oversizing).

Slab-on-grade floor: acommon name for a concretefloor of a building that is pouredat ground level, or “at grade.”

Thermostat: a switch thatturns a heating and air-conditioningsystem on or off according to the

temperature of the spacewhere it is located (also seeProgrammable thermostat).

Tracing wire, tracing tape:metal wire or foil-backed tapeplaced in a trench above theburied pipe of an EES loop tomake it easier to find it in thefuture and to avoid damageduring future excavation.

Tremie line: used in theinstallation of a vertical loop; apipe inserted to the bottom ofthe borehole through which groutis piped down, and retracted asthe hole fills (CSA requirement),designed to eliminate air pocketsand ensure good contact with thesoil (also see Grout, Grouting).

Vertical loop: see Loop.

Water coil: see Coil.

Water heating/air-condition-ing systems, Conventional: seeConventional systems.

Water-water heat pump: aheat pump designed to producehot water or chilled water. Heatedor chilled water is used to conveyenergy using water as a heat-transfer medium. Hot water isoften used in a radiant floor heatsystem, and chilled water is usedin conjunction with a fan coilunit; can also be used to heatwater for domestic use.

Well-water system: an open-loop return well; typically consistsof two drilled wells – the primarywell and the return well.

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Conversion Factors

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Multiply by

0.293

0.000293

3.413

3413.000

10.760

0.093

3.281

0.305

0.264

3.785

4.546

1.800 and add 32

0.555

To

watts

kilowatts

Btu/h

Btu/h

sq. ft.

m2

feet

metres

U.S. gallons

litres

litres

°F

°C subtract 32 and

To Convert

Btu/h

Btu/h

watts

kilowatts

m2

sq. ft.

metres

feet

litres

U.S. gallons

imperial gallons

°C

°F