ac residential

7/30/2019 AC Residential

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AREN 4570

Air Conditioning Systems for Residential Applications

Bojana BarovicCraig RaceyBrent VollenweiderMichelle Walker


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10/14/2002 Building Electrical Systems Page 1Project #1

Table of Contents:

Executive Summary pg 2

Introduction pg 2-5

Types of Res. AC Units pg 2

Standard Efficiency vs. High Efficiency pg 3

Other System Components pg 3-5

Trane Product Summary pg 5-7

Carrier Product Summary pg 7-9

Lennox Product Summary pg 9-11

York Product Summary pg 11-12

General Design Guidelines pg 12-13

Sample Calculations (Economic Analysis) pg 14

Conclusions pg 15

References pg 16

Appendix pg 17-48


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Executive Summary:

The primary purpose of this report is to provide basic electricaland economic information regarding current air conditioning optionsavailable to residential consumers. Although there are several

different options for maintaining indoor air quality in a residence, thefocus of this report is the most common residential air conditioningsystem; the unitary outdoor unit, or central air conditioning.

There are four major manufacturers of these central airconditioning systems: Trane, Carrier, Lennox, and York. Each of thesemanufacturers makes several models of varying efficiencies, typicallyranging in nominal cooling capacity from 1 or 1.5 tons to 5 tons.Efficiency is measured by the SEER ratio, which expresses coolingoutput (Btuh) divided by power input (W). Standard efficiency modelshave a SEER rating ranging from 10 to 12. High efficiency modelshave a SEER rating ranging from 12 to 18.

Example calculations were performed to compare the economicbenefits of a high efficiency unit vs. a standard efficiency unit for oneCarrier model. The high efficiency model, with a SEER of 12, saves$35.42/yr over the standard efficiency model. The initial cost of thehigh efficiency model was $300 greater than that of the standardefficiency model, resulting in a payback period of approximately 8.5years. The expected lifespan of unitary residential units is at least 10years. Therefore, even a slightly more efficient model can be an

economic benefit. If an even more efficient model with an SEER of 14 16, which are readily available today, were used, the savings couldeven be more significant.

When designing a residential electrical system, several aspectsof the air conditioning unit must be known. In order to size the branchcircuit and the conduit, the circuit breaker, and the disconnect for theunit, it is necessary to know the operating voltage of the unit, itspower consumption, and is rated line current. Although most units areavailable in 3-phase or 1-phase models, the 1-phase models are

typically used in residential applications.

There are other factors to be considered when buying a centralair conditioning system. The manufacturers advertise features such asappearance, durability, maintenance / installation costs, types ofcomponents, warranty, and noise levels in decibels. All of thesefeatures are a matter of personal preference.


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Introduction:

This objective of this report is to explore the various airconditioning options available to residential consumers and todetermine their typical electrical demands. First, a discussion of

various types of residential air conditioning is completed. A definitionof standard and high efficiency units follows. Additional airconditioning components, individual as well as those within a unitaryunit, are discussed next. The focus of this report is on availableunitary units; as such, typical models available from four topmanufacturers are then presented. After general design guidelines arediscussed, some sample calculations showing the possible economicbenefits of using high efficiency units are given.

Types of Residential Air Conditioning Units:

Cooling needs for residential buildings are generally controlled byclimatic conditions rather than by internal loads. Therefore, the typeof air conditioning unit selected is largely a function of the localclimate. For example, evaporative coolers are used primarily in hot,arid climates because they raise indoor humidity levels whilesimultaneously decreasing indoor air temperatures. In a humidclimate, window mounted units that work on the same principals as arefrigerator are of chosen to cool small spaces. However, the mostcommon form of air conditioning is the unitary air conditioning unit, as60% of U.S. residents use central air conditioning to cool their homes.

Unitary air conditioning units, typically located outside, operateon the refrigeration cycle as do window-mounted units, but theytypically have much greater cooling capacities. These units functionwell in most climates and are by far the most common productavailable on the market. This report will focus predominantly on theseoutdoor air conditioning units. Heat pumps, which supply 25% ofresidential buildings nationally, will be disregarded as they provideheating as well as cooling. Small packaged air handling units, whichprovide heating and cooling for 5% of residential buildings nationally,

will likewise be disregarded, because they again do more than cool,and are impractical for most homes(http://www.residential.carrier.com). The following diagram illustratesthe main components of central air conditioning systems.
http://www.residential.carrier.com/http://www.residential.carrier.com/


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Standard vs. High Efficiency:

There are as many different efficiency standards as there are

types of air conditioning systems. The SEER efficiency rating appliesto central air conditioning systems as well as heat pumps. SEERstands for Seasonal Energy Efficiency Ratio. It is a ratio of the totalcooling output averaged over a year (Btuh) divided by the requiredelectrical power input (Watts). Because increased cooling output anddecreased energy input results in a higher SEER, greater SEER valuesimply more efficient units. The current minimum SEER for airconditioning units allowed by code is 10.0. Standard efficiency unitsare defined as having a SEER between 10 and 12, and high efficiencymodels have an SEER ranging anywhere from 12 to 18.

Other System Components:

Within the air conditioner, electrical energy is primarily consumedby three components:

1. compressor - compresses the refrigerant from a liquid into a gas2. fan moves air across the coils and exhausts the heated air3. pump used to circulate the refrigerant through the system

Within these three components, the compressor usually uses the most

energy in the air conditioner. As such, one technique to improve theoverall efficiency of an air conditioning unit is to improve the efficiencyof the compressor. Following is a diagram of a Trane brand airconditioner.


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An air conditioning unit is not the only component of an HVACsystem in a residential dwelling. A heating component is also neededto accompany the air conditioner such as a furnace or a boiler. Otherunits can be used in place of an air conditioning unit, such as a heatpump or a small packaged air conditioning unit. Added componentssuch as an air filter and or a humidifier add to the energy consumptionof these system. In addition, several types of air quality devices areavailable for residential dwellings, including humidifiers and airpurifiers. This report will focus on unitary air conditioning unitsavailable from Trane, Carrier, Lennox, and York, ranging in cooling

capacity from 1 3 tons.

Trane Product Summary:

ProductDesc:

Dimensions: (Height,width, depth) (in.)

Efficiency:(Standardor High)

OperatingVoltage:

Phase:(1 or

3)

NominalCooling

Capacity:(Btuh)

NominalCooling

Capacity:(Tons) SEER:

EstimatedInput

Power:(kW)

EstimatedLine

Current:(A)

CBSize:(A)

MinimumWireSize:

(AWG)Cos

($

TRANE RESIDENTIAL AIR CONDITIONERS

XE 1200 Air Conditioner

TCP024F 25 x 36 x 56 High 208 3 23800 2.0 12.00 1.98 5.51 15 14.00

25 x 36 x 56 High 230 1 23800 2.0 12.00 1.98 8.62 15 14.00

TCP030F 29 x 36 x 56 High 208 3 30000 2.5 12.00 2.50 6.94 15 14.00

29 x 36 x 56 High 230 1 30000 2.5 12.00 2.50 10.87 15 14.00

TCP036F 29 x 36 x 56 High 208 3 36000 3.0 12.00 3.00 8.33 15 14.00

29 x 36 x 56 High 230 1 36000 3.0 12.00 3.00 13.04 20 14.00

XE 1200 Over/Under Air Conditioner

TCH024B 30 x 32 x 44 High 208 3 24000 2.0 12.05 1.99 5.53 15 14.00

30 x 32 x 44 High 230 1 24000 2.0 12.05 1.99 8.66 15 14.00

TCH030B 30 x 32 x 44 High 208 3 30000 2.5 12.60 2.38 6.61 15 14.00


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30 x 32 x 44 High 230 1 30000 2.5 12.60 2.38 10.35 15 14.00

TCH036B 30 x 32 x 44 High 208 3 36000 3.0 12.60 2.86 7.93 15 14.00

30 x 32 x 44 High 230 1 36000 3.0 12.60 2.86 12.42 20 14.00

XL 1200 Air Conditioner

TCX024G 25 x 36 x 56 High 208 3 24200 2.0 12.00 2.02 5.60 15 14.00

25 x 36 x 56 High 230 1 24200 2.0 12.00 2.02 8.77 15 14.00TCX030G 29 x 36 x 56 High 208 3 30600 2.6 12.05 2.54 7.05 15 14.00

29 x 36 x 56 High 230 1 30600 2.6 12.05 2.54 11.04 15 14.00

TCX036G 29 x 36 x 56 High 208 3 37000 3.1 12.05 3.07 8.52 15 14.00

29 x 36 x 56 High 230 1 37000 3.1 12.05 3.07 13.35 20 14.00

XL 1400 Air Conditioner

TCY024G 29 x 36 x 56 High 208 3 24000 2.0 14.00 1.71 4.76 15 14.00

29 x 36 x 56 High 230 1 24000 2.0 14.00 1.71 7.45 15 14.00

TCY030G 29 x 36 x 56 High 208 3 30600 2.6 14.00 2.19 6.07 15 14.00

29 x 36 x 56 High 230 1 30600 2.6 14.00 2.19 9.50 15 14.00

TCY036G 29 x 36 x 64 High 208 3 36000 3.0 14.10 2.55 7.09 15 14.00

29 x 36 x 64 High 230 1 36000 3.0 14.10 2.55 11.10 15 14.00

TCK Air Conditioner

TCK024F 31 x 32 x 44 High 208 3 24000 2.0 12.00 2.00 5.55 15 14.00

31 x 32 x 44 High 230 1 24000 2.0 12.00 2.00 8.70 15 14.00

TCK030F 31 x 32 x 44 High 208 3 30000 2.5 12.00 2.50 6.94 15 14.00

31 x 32 x 44 High 230 1 30000 2.5 12.00 2.50 10.87 15 14.00

TCK036F 31 x 32 x 44 High 208 3 36000 3.0 12.00 3.00 8.33 15 14.00

31 x 32 x 44 High 230 1 36000 3.0 12.00 3.00 13.04 20 14.00

TCC Air Conditioner

TCC024F 25 x 36 x 55 High 208 3 23400 2.0 12.00 1.95 5.41 15 14.00

25 x 36 x 55 High 230 1 23400 2.0 12.00 1.95 8.48 15 14.00

TCC030F 29 x 36 x 55 High 208 3 29800 2.5 12.05 2.47 6.86 15 14.00

29 x 36 x 55 High 230 1 29800 2.5 12.05 2.47 10.75 15 14.00

TCC036F 29 x 36 x 56 High 208 3 35200 2.9 12.05 2.92 8.11 15 14.00

29 x 36 x 56 High 230 1 35200 2.9 12.05 2.92 12.70 20 14.00

*Costs were unavailable from local dealers or the manufacturer. However, costs canbe estimated by comparing particular models with similar units produced by Carrier,Lennox, or York.

Trane products utilize Trane patented components. In this waythey are able to optimize their efficiency by controlling every part ofthe cooling unit. Examples of Tranes patented air conditioningcomponents include the Climatuff compressor and the Spine Fin TM

coils, which dissipate heat even in harsh environmental conditions.

Trane also touts many other reasons for choosing their product:(http://www.trane.com/residential/bcorner/)

1. High-end products are more energy efficient, so utility bills aresignificantly reduced.
http://www.trane.com/residential/bcorner/http://www.trane.com/residential/bcorner/


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Our research shows that Trane has moderately efficient airconditioning units. None of the Trane units have a SEERabove 14.

2. With high-end products you can have the added benefit of

variable speed technology which offers both the joy ofcontinuous comfort and the quietest operation possible.

Though the cabinet is insulated, Trane does not advertisedecibel levels to back this claim up.

3. 10-year parts and labor extended warranties may be purchasedas an option adding even more peace of mind.

4. With high efficiency products, a homeowner can take advantageof zoning for the ultimate in home comfort.

5. A high efficiency heating and air conditioning system adds valueto a home if a homeowner ever should decide to sell.

Cutsheets from which product information was obtained areincluded in the appendix.

Carrier Product Summary:

ProductDesc:



OperatingVoltage:

Phase:(1 or

3)

NominalCooling

Capacity:(Btuh)

NominalCooling


EstimatedInput

Power:(kW)

EstimatedLine

Current:(A)

CBSize:(A)

MinimumWireSize:

(AWG)Co

($

CARRIER RESIDENTIAL AIR CONDITIONERS

Weathermaker 38TDB Air Conditioner

38TDB024-30 34 x 23 x 28 High 208 3 24000 2.0 15.00 1.60 4.44 15 14.00

34 x 23 x 28 High 230 1 24000 2.0 15.00 1.60 6.96 15 14.00

38TDB036-30 40 x 30 x 35 High 208 3 36000 3.0 16.50 2.18 6.06 15 14.00

40 x 30 x 35 High 230 1 36000 3.0 16.50 2.18 9.49 15 14.00

Weathermaker 38TSA Air Conditioner

38TSA024-30 40 x 30 x 35 High 208 3 25000 2.1 15.60 1.60 4.45 15 14.00

40 x 30 x 35 High 230 1 25000 2.1 15.60 1.60 6.97 15 14.00

38TSA030-30 40 x 30 x 35 High 208 3 30000 2.5 15.75 1.90 5.29 15 14.00

40 x 30 x 35 High 230 1 30000 2.5 15.75 1.90 8.28 15 14.00

38TSA036-30 40 x 30 x 35 High 208 3 36200 3.0 15.75 2.30 6.38 15 14.00 40

40 x 30 x 35 High 230 1 36200 3.0 15.75 2.30 9.99 15 14.00 40

Weathermaker 38TXA Air Conditioner

38TXA024-30 34 x 30 x 35 High 208 3 26000 2.2 14.00 1.86 5.15 15 14.00

34 x 30 x 35 High 230 1 26000 2.2 14.00 1.86 8.07 15 14.00

38TXA030-30 28 x 30 x 35 High 208 3 29600 2.5 14.00 2.11 5.87 15 14.00

28 x 30 x 35 High 230 1 29600 2.5 14.00 2.11 9.19 15 14.00
http://www.trane.com/residential/personaltouch/warranties.asphttp://www.trane.com/residential/personaltouch/warranties.asp


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38TXA036-30 34 x 30 x 35 High 208 3 36000 3.0 14.00 2.57 7.14 15 14.00

34 x 30 x 35 High 230 1 36000 3.0 14.00 2.57 11.18 15 14.00

Weathermaker 38TZA Air Conditioner

38TZA018-30 34 x 23 x 28 High 208 3 18000 1.5 13.50 1.33 3.70 15 14.00

34 x 23 x 28 High 230 1 18000 1.5 13.50 1.33 5.80 15 14.00

38TZA024-30 28 x 30 x 35 High 208 3 23600 2.0 13.70 1.72 4.78 15 14.00

28 x 30 x 35 High 230 1 23600 2.0 13.70 1.72 7.49 15 14.00

38TZA030-30 28 x 30 x 35 High 208 3 29200 2.4 14.00 2.09 5.79 15 14.00

28 x 30 x 35 High 230 1 29200 2.4 14.00 2.09 9.07 15 14.00

38TZA036-30 28 x 30 x 35 High 208 3 35800 3.0 14.10 2.54 7.05 15 14.00

28 x 30 x 35 High 230 1 35800 3.0 14.10 2.54 11.04 15 14.00

Weathermaker 38TUA Air Conditioner

38TUA018-30 32 x 34 x 23 Standard 208 3 18000 1.5 13.00 1.38 3.84 15 14.00

32 x 34 x 23 Standard 230 1 18000 1.5 13.00 1.38 6.02 15 14.00

38TUA024-30 31 x 28 x 23 Standard 208 3 23400 2.0 13.00 1.80 5.00 15 14.00

31 x 28 x 23 Standard 230 1 23400 2.0 13.00 1.80 7.83 15 14.0038TUA030-30 31 x 28 x 23 Standard 208 3 29600 2.5 12.20 2.43 6.73 15 14.00

31 x 28 x 23 Standard 230 1 29600 2.5 12.20 2.43 10.55 15 14.00

38TUA036-30 31 x 28 x 30 Standard 208 3 36600 3.1 13.00 2.82 7.81 15 14.00

31 x 28 x 30 Standard 230 1 36600 3.1 13.00 2.82 12.24 20 14.00

Weathermaker 38TKB Air Conditioner

38TUA018-30 22 x 23 x 28 Standard 208 3 18000 1.5 12.50 1.44 4.00 15 14.00

22 x 23 x 28 Standard 230 1 18000 1.5 12.50 1.44 6.26 15 14.00

38TUA024-30 22 x 23 x 28 Standard 208 3 23800 2.0 11.50 2.07 5.74 15 14.00

22 x 23 x 28 Standard 230 1 23800 2.0 11.50 2.07 9.00 15 14.00

38TUA

030-30 31 x 23 x 28 Standard 208 3 29800 2.5 11.20 2.66 7.39 15 14.00

31 x 23 x 28 Standard 230 1 29800 2.5 11.20 2.66 11.57 15 14.00

38TUA036-30 31 x 23 x 28 Standard 208 3 35000 2.9 11.50 3.04 8.45 15 14.00 28

31 x 23 x 28 Standard 230 1 35000 2.9 11.50 3.04 13.23 20 14.00 28

*Costs provided are based on purchase and installation of the units, and wereobtained from local dealers. Costs for other units may be estimated based on SEERand cooling capacity relative to those units with provided costs.

As one of the leading HVAC companies in the world, Carrier usesonly high quality energy saving components in their products. In theirhigh efficiency air conditioning units, they use only Puron refrigerant,

replacing the R-22 coolant used currently by other manufacturers.This refrigerant is designed to protect the environment as it does notcontain any chlorine, as well as work more efficiently. All Carrierproducts are galvanized and coated with metals designed to protectthem for many years. In addition, materials with superior heattransfer qualities allow for higher efficiency since heat will betransferred to the outdoors easier. The scroll compressors used aredesigned for performance along with quietness. Carrier works hard to


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develop new products that increase the efficiency of their products,while keeping costs to the consumers low. Cutsheets from which thisinformation was obtained are included in the appendix.

Lennox Product Summary:

ProductDesc:



OperatingVoltage:

Phase:(1 or

3)

NominalCooling

Capacity:(Btuh)

NominalCooling


EstimatedInput

Power:(kW)

EstimatedLine

Current:(A)

CBSize:(A)

MinimumWireSize:

(AWG)Cos

($)

LENNOX RESIDENTIAL AIR CONDITIONERS:

Elite 11 Air Conditioner:

HS29-012 25 x 24.25 x 24.25 Standard 208 3 12000 1.0 11.05 1.09 3.01 15 14.00 900

25 x 24.25 x 24.25 Standard 230 1 12000 1.0 11.05 1.09 4.72 15 14.00 800

HS29-018 25 x 24.25 x 24.25 High 208 3 18000 1.5 12.00 1.50 4.16 15 14.00

26 x 24.25 x 24.25 High 230 1 18000 1.5 12.00 1.50 6.52 15 14.00

HS29-024 25 x 24.25 x 24.25 Standard 208 3 24000 2.0 11.50 2.09 5.79 15 14.00

26 x 24.25 x 24.25 Standard 230 1 24000 2.0 11.50 2.09 9.07 15 14.00

HS29-030 29 x 24.25 x 24.25 Standard 208 3 30000 2.5 11.50 2.61 7.24 15 14.00

30 x 24.25 x 24.25 Standard 230 1 30000 2.5 11.50 2.61 11.34 15 14.00

HS29-036 33 x 24.25 x 24.25 Standard 208 3 36000 3.0 11.20 3.21 8.92 15 14.00 120

34 x 24.25 x 24.25 Standard 230 1 36000 3.0 11.20 3.21 13.98 20 14.00 110


HS26-018

27.875 x 25.875 x29.875 High 208 3 18000 1.5 13.40 1.34 3.73 15 14.00 145

27.875 x 25.875 x29.876 High 230 1 18000 1.5 13.40 1.34 5.84 15 14.00 135

HS26-024

27.875 x 25.875 x29.875 High 208 3 24000 2.0 14.00 1.71 4.76 15 14.00

27.875 x 25.875 x

29.876 High 230 1 24000 2.0 14.00 1.71 7.45 15 14.00HS26-030

27.875 x 25.875 x29.875 High 208 3 30000 2.5 14.05 2.14 5.93 15 14.00

27.875 x 25.875 x29.876 High 230 1 30000 2.5 14.05 2.14 9.28 15 14.00

HS26-036

27.875 x 25.875 x29.875 High 208 3 36000 3.0 14.00 2.57 7.14 15 14.00 180

27.875 x 25.875 x29.876 High 230 1 36000 3.0 14.00 2.57 11.18 15 14.00 170


HS27-024

30.875 x 32.125 x34.0625 High 208 3 24000 2.0 14.70 1.63 4.53 15 14.00 185

30.875 x 32.125 x34.0625 High 230 1 24000 2.0 14.70 1.63 7.10 15 14.00 175

HS27-030

30.875 x 32.125 x34.0625 High 208 3 30000 2.5 15.50 1.94 5.37 15 14.00

30.875 x 32.125 x34.0625 High 230 1 30000 2.5 15.50 1.94 8.42 15 14.00

HS27-036

40.875 x 32.125 x34.0625 High 208 3 36000 3.0 15.60 2.31 6.41 15 14.00 210

40.875 x 32.125 x34.0626 High 230 1 36000 3.0 15.60 2.31 10.03 15 14.00 200

Power Saver Air Conditioner:

HS21-411

40.875 x 32.125 x34.0625 High 208 3 36000 3.0 15.75 2.29 6.34 15 14.00 290

40.875 x 32.125 x34.0626 High 230 1 36000 3.0 15.75 2.29 9.94 15 14.00 280

HS21-511

40.875 x 32.125 x34.0627 High 208 3 48000 4.0 14.05 3.42 9.48 15 14.00 300

40.875 x 32.125 x High 230 1 48000 4.0 14.05 3.42 14.85 20 14.00 290


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34.0628

HS21-651

44.875 x 32.125 x34.0625 High 208 3 54000 4.5 13.50 4.00 11.10 15 14.00

44.875 x 32.125 x34.0626 High 230 1 54000 4.5 13.50 4.00 17.39 25 14.00

Merit Series Air Conditioner:

10ACC-18 25 x 22.25 x 22.25 Standard 208 3 18000 1.5 10.65 1.69 4.69 15 14.00 750

Standard 230 1 18000 1.5 10.65 1.69 7.35 15 14.00 650

10ACC-24 25 x 22.25 x 22.25 Standard 208 3 24000 2.0 11.25 2.13 5.92 15 14.00

Standard 230 1 24000 2.0 11.25 2.13 9.28 15 14.00

10ACC-30 25 x 24.25 x 24.25 Standard 208 3 30000 2.5 10.85 2.76 7.67 15 14.00

Standard 230 1 30000 2.5 10.85 2.76 12.02 20 14.00

10ACC-36 25 x 24.25 x 24.25 Standard 208 3 36000 3.0 10.90 3.30 9.17 15 14.00 890

Standard 230 1 36000 3.0 10.90 3.30 14.36 20 14.00 790

Dave Lennox Signature Collection:

HSX15-24

27.875 x 25.875 x29.875 High 208 3 24000 2.0 14.00 1.71 4.76 15 14.00 160

High 230 1 24000 2.0 14.00 1.71 7.45 15 14.00 150

HSX15-30 30.875 x 32.125 x34.0625 High 208 3 30000 2.5 14.70 2.04 5.66 15 14.00

High 230 1 30000 2.5 14.70 2.04 8.87 15 14.00

HSX15-36

30.875 x 32.125 x34.0625 High 208 3 36000 3.0 14.60 2.47 6.84 15 14.00 195

High 230 1 36000 3.0 14.60 2.47 10.72 15 14.00 185

*The provided costs are a representative sampling of the unit costs only(uninstalled), based on data available from local dealers.

With a full line of both commercial and residential airconditioners, Lennox is one of the leading suppliers of air conditioningequipment in the nation. The Lennox residential product line consistsof many types of equipment, all designed to provide a comfortable,healthy indoor environment in an energy efficient, economic manner.Typical products include various heating devices, indoor air qualitydevices, packaged heating/cooling equipment, unitary coolingequipment, and various control systems for these products. Asmentioned previously, the focus of this report is the typical unitary airconditioner.

Standard Lennox residential unitary air conditioners range incooling capacity from 1-ton to 5-tons. This wide range makes itpossible to cool even very large residences with a single unit. As can

be seen in the table above, several different models are available forsimilar cooling requirements. Lennox offers both standard and high-efficiency units, the latter with a maximum SEER of approximately 16.The high-efficiency units typically have a greater initial cost than theirstandard-efficiency counterparts; however, the cost in energy savingscan quickly offset this initial burden. An example calculation showingthe payback period of a typical high-efficiency unit vs. a standard-efficiency unit is presented on pages 12 - 13. It should be noted that


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3-phase units cost approximately $100 more than 1-phase units of thesame model and cooling capacity. Cutsheets from which thisinformation was obtained can are included in the appendix.

York Product Summary:

ProductDesc:



OperatingVoltage:

Phase:(1 or

3)

NominalCooling

Capacity:(Btuh)

NominalCooling


EstimatedInput

Power:(kW)

EstimatedLine

Current:(A)

CBSize:(A)

MinimumWireSize:

(AWG)

YORK RESIDENTIAL AIR CONDITIONERS

H4TS Air Conditioner

H4TS024 30 x 24 x 24 High 208 3 24400 2.0 14.50 1.68 4.67 15 14.00

30 x 24 x 24 High 230 1 24400 2.0 14.50 1.68 7.32 15 14.00

H4TS030 30 x 24 x 24 High 208 3 21600 1.8 14.60 1.48 4.11 15 14.00

30 x 24 x 24 High 230 1 21600 1.8 14.60 1.48 6.43 15 14.00

H4TS036 32 x 25 x 25 High 208 3 37000 3.1 15.50 2.39 6.63 15 14.00

32 x 25 x 25 High 230 1 37000 3.1 15.50 2.39 10.38 15 14.00

H1RE Air Conditioner

H1RE024S06 33 x 37 x 27 High 208 3 25400 2.1 14.00 1.81 5.04 15 14.00

33 x 37 x 27 High 230 1 25200 2.1 14.00 1.80 7.83 15 14.00

H1RE030S06 39 x 37 x 27 High 208 3 30600 2.6 14.00 2.19 6.07 15 14.00

39 x 37 x 27 High 230 1 28800 2.4 13.10 2.20 9.56 15 14.00

H1RE036S06 39 x 37 x 27 High 208 3 36000 3.0 14.00 2.57 7.14 15 14.00

39 x 37 x 27 High 230 1 36000 3.0 14.20 2.54 11.02 15 14.00

H2RC Air Conditioner

H2RC018SO6 25 x 35 x 23 High 208 3 20200 1.7 13.75 1.47 4.08 15 14.00

25 x 35 x 23 High 230 1 19600 1.6 12.50 1.57 6.82 15 14.00

H2RC024SO6 25 x 35 x 23 High 208 3 25200 2.1 13.50 1.87 5.18 15 14.00

25 x 35 x 23 High 230 1 24000 2.0 12.00 2.00 8.70 15 14.00

H2RC030SO6 27 x 37 x 27 High 208 3 32000 2.7 13.75 2.33 6.46 15 14.00

27 x 37 x 27 High 230 1 30600 2.6 12.25 2.50 10.86 15 14.00

H2RC036SO6 27 x 37 x 27 High 208 3 34800 2.9 12.00 2.90 8.05 15 14.00

27 x 37 x 27 High 230 1 35000 2.9 12.00 2.92 12.68 20 14.00

H4AH Air Conditioner

H4AH024 24 x 24 x 24 Standard 208 3 24600 2.1 13.00 1.89 5.25 15 14.00

24 x 24 x 24 Standard 230 1 24200 2.0 12.00 2.02 8.77 15 14.00

H4AH030 30 x 24 x 24 Standard 208 3 30800 2.6 13.00 2.37 6.58 15 14.00

30 x 24 x 24 Standard 230 1 30200 2.5 12.00 2.52 10.94 15 14.00

H4AH036 36 x 35 x 35 Standard 208 3 37400 3.1 13.50 2.77 7.69 15 14.00

36 x 35 x 35 Standard 230 1 36800 3.1 12.20 3.02 13.11 20 14.00

H4DB Air Conditioner

H4DB012 20 x 24 x 24 Standard 208 3 13600 1.1 10.00 1.36 3.77 15 14.00

20 x 24 x 24 Standard 230 1 13600 1.1 10.00 1.36 5.91 15 14.00

H4DB018 20 x 24 x 24 Standard 208 3 18800 1.6 10.30 1.83 5.07 15 14.00

20 x 24 x 24 Standard 230 1 18800 1.6 10.30 1.83 7.94 15 14.00

H4DB024 20 x 24 x 24 Standard 208 3 25000 2.1 10.60 2.36 6.55 15 14.00

20 x 24 x 24 Standard 230 1 25000 2.1 10.60 2.36 10.25 15 14.00


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H4DB030 24 x 24 x 24 Standard 208 3 30000 2.5 12.20 2.46 6.83 15 14.00

24 x 24 x 24 Standard 230 1 30000 2.5 12.20 2.46 10.69 20 14.00

H4DB036 24 x 24 x 24 Standard 208 3 37600 3.1 11.60 3.24 9.00 15 14.00

24 x 24 x 24 Standard 230 1 36600 3.1 12.40 2.95 12.83 20 14.00

*Provided costs are based on data available from local dealers, and

include purchase and installation. These are representative of typicalYork models with similar cooling capacities and efficiencies.

York is known for using very high grade components in their airconditioning units. Their top-of-the-line units use a single twin pistoncompressor that allows the air conditioner to have a cooling efficiencyup to 16 SEER. This is because it allows the BTUH to be almostdoubled compared to a normal compressor. Not only are these unitsable to handle more BTUH, they are also able to cool the space in only60% the time that a standard unit would take. The high efficiency ofthe air conditioner results in 40% of the energy consumption of a

standard unit. Another feature York includes in their units is lowerinstallation costs. York produces to make units that are easy to installby using wiring connections that are easy to connect. All units containenough refrigerant for the smallest matching indoor coil and 15 feet ofinterconnecting piping, allowing the units to have a much smallerfootprint compared to their competitors. They also provide morecontrol over humidity for a price that is insignificant.

General Design Guidelines:

When a unitary air conditioning unit is utilized in a residence,several considerations must be made regarding the design of theelectrical system. First, the actual piece of equipment to be usedshould be specified and its particular electrical requirementsdetermined. Specific items to consider are the operating voltage ofthe unit (including phase), the kVA rating of the unit, the power factor,and the line current. Based on this information, the conductor size canbe determined for the branch circuit used to feed the unit, thedisconnect switch for the unit can be designed, and the circuit breakerfor the unit can be sized. In general, unitary air conditioning units areconnected to a power panel as an individual circuit. However, some of

the smaller units draw very little current, and the possibility of placingadditional equipment on the same circuit should be considered.

Unfortunately, the desired electrical information is usually notprovided directly by the manufacturer. It is therefore necessary toestimate the necessary input power of the unit and the resulting linecurrent based on the known operating voltage, the nominal cooling


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capacity (Btuh), and the SEER. In dwellings, common operatingvoltages are 208-V (3-phase) and 230-V (1-phase). Most unit modelsare available for either case. The input power (kW) required can beestimated by dividing the nominal cooling capacity (Btuh) by the SEER.Next, the line current can be calculated by dividing the required input

power (kW) by the line voltage and any required factors. Thedownside of this method is that the power factor of the unit remainsunknown, as does the total apparent power consumed by the airconditioning unit. This is typically not a major concern in residentialapplications, however, as customers are generally not penalized forsystems with large power factors. A problem could occur with sizing aresidential transformer if the total kVA rating of the air conditioner isunknown.

When sizing the circuit breaker for the air conditioner, the unitshould be considered as a continuous load. Most smaller units willrequire the use of the minimum 15 amp circuit breaker, while largerunits will require larger circuit breakers. The branch circuit(s) feedingthe unit(s) should be sized based on tables 310.16-310.19 in the NEC(NFPA, 2001). The ampacity of the conductor should be greater thanthat of the circuit breaker and the local disconnect. In addition, thedisconnect should be designed to isolate any fault caused by anoverload as well as to allow for manual isolation of the unit from therest of the electrical system.

A diagram showing the typical installation of a unitary air

conditioner is shown below. Typically, unitary air conditioners areinstalled outside with little or no shelter. Therefore, an additionalcomponent of the electrical system to be considered is conduit. Theconduit should be designed in order to protect the enclosed conductorfrom weather conditions and potential fault conditions.


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Sample Calculations:

Assumptions:Operating Schedule

4 months a year (123 days)

8 hours a day24 hrs a day 984 hrs/yr

Energy Cost.06 $ / kwh

Installed Upfront Cost$ 2800 for the high efficiency model 3 ton unit$ 2500 for the low efficiency model 3 ton unit

SEERHigh efficiency SEER=12.0Low efficiency SEER=10.0

Calculations: (High Efficiency)

yrkwhyr

hrkw

kww

kwh

SEER

btuh

12.177$$06.9840.3

0.31000

1

)(0.12

36000

=

=

Calculations: (Low Efficiency)

yrkwhyr

hrkw

kww

kwh

SEER

btuh

54.212$$06.9846.3

6.31000

1

)(0.10

36000

=

=

Payback Period:

yearsiodPaybackPer 5.812.177$54.212$

500,2$800,2$=

=

*It should be noted that the high efficiency model used in this

example has the minimum high efficiency SEER rating of 12.0. If abetter high efficiency model were to be used, a shorter payback periodcould be achieved. In addition, the typical lifespan of a unitary airconditioning unit is a minimum of 10 years, and thus even a smallincrease in efficiency can be economically beneficial.


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Conclusion:

When designing a residential electrical system, variousconsiderations must be made regarding the air conditioning unit,including sizing the conduit, conductors, circuit breaker, and main

disconnect for the air conditioner. In this report, the products of fourmain manufacturers were analyzed to represent the most commonproducts available on the market today. The products werecategorized into two groups by these manufacturers; high andstandard efficiency units. The main concern for residential airconditioning units is higher first cost spent for the high efficiency unitsversus the energy savings. As shown in the provided samplecalculations, even a moderately efficient unit can be economicallypractical compared to a standard efficiency unit. While differentmanufacturers advertise various aspects of their equipment, mostresidential units are quite similar. Typical cooling capacities rangefrom 1 5 tons, and prices can range from several hundred to severalthousand dollars, accordingly. As environmental concerns continue togrow, so too will the technology employed by air conditioning unitmanufacturers, which will result in more efficient units.


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References:

Broomfield Sheet Metal (York)

2851 Industrial LaneBroomfield, CO 80020

Phone: 303.466.4222

Cooper Exchange Systems Ltd. (Carrier)7650 W 120th Ave.

Broomfield, CO 80020Phone: 303.466.4326

www.global.carrier.com

H & M Mechanical Llc. (Lennox)

600 South SunsetUnit C

Longmont, CO 80026Phone: 303.664.9865

Home Run Heating (Carrier)624 Main St.Longmont, CO 80501

Phone: 303.678.0777

Jones Heating & Cooling (York)

990 Lilac St.Broomfield, CO 80020

Phone: 303.947.9170

www.lennox.com

Meyer Heating & Air Conditioning (York)

260 Pearl Street

Boulder, CO 80302Phone: 303.442.6640

National Fire Protection Association Inc. National Electric Code, 2002 Edition,

NFPA: 2002.

Stein, Benjamin and Reynolds, John. Mechanical and Electrical Equipmentfor Buildings, 8th edition, John Wiley and Sons Inc. New York: 1992.

www.trane.com

www.york.com
http://www.global.carrier.com/http://www.lennox.com/http://www.trane.com/http://www.york.com/http://www.york.com/http://www.trane.com/http://www.lennox.com/http://www.global.carrier.com/


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Appendix:

ac residential

Documents