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Air Source Heat Pump Presentation

Andrew Knill Monmouthshire County Council

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What Made Us Consider Air Source Heat Pumps?

Increased Number Of Complaints From Tenants About Their Solid Fuel and Electric Storage Radiators Systems.

Sharply Rising Cost Of Oil (Winter 2005)

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Solid Fuel Complaints

Older Tenants: Unable To Carry Coal and Ashes

Quite Expensive To Run Home Help Often

Required.

Younger Tenants: Unable To Control System.High Running Costs.Dirty To Operate.Danger To Children.

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Electric Storage Radiator Complaints Unable To Control: Too Hot In The Night

and The Morning.No Heat Left

By The Evening.

High Running Costs.

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Monmouthshire County CouncilBreakdown of Heating Fuel TypesJanuary 2005

Number Of Properties Percentage

Gas 3045 84Oil 58 2Solid Fuel 227 6Electric 310 9

3640 15%

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Cae Capel, Great Oak, Near Raglan. Small rural site of 6 two bedroom bungalows

heated with modern slim-line electric storage radiators.

Properties were built with cavity wall insulation and the loft insulation had recently been upgraded. The windows and doors were single glazed with aluminium frames.

Tenants were all old aged pensioners and had been campaigning for an alternative form of heating for a long time. Their main complaint was the existing systems were expensive to run and the radiators ran out of heat by the evening.

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The tenants wanted LPG or Oil Heating.

The site layout meant that communal LPG or Oil storage tanks would have to be provided as there was insufficient room for individual tanks to be located in the gardens.

The tenants request was turned down because of bad previous experiences with communal storage schemes. (mainly metering, fuel contamination and tanks running out of fuel)

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CAE CAPEL, GREAT OAK

579111315

CAE CAPEL, GREAT OAK

579111315

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After further consultation with the tenants it was agreed to provide them with a wet central heating system with radiators fuelled by Combined Electric Primary Storage Units.

The units chosen were the Gledhill Electomate 2000’s

The systems were to use Tariff 10 electricity.

The tenants were to be set up on the Easy Warm scheme to ensure their fuel bills were capped and affordable.

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Enquiries were made to the electricity supplier over the capacity of the network in June 2005.

It took until October 2005 before a quotation was received.

The quotation was for the sum of £7,500 and specified a minimum lead in time of 3 Months as a new transformer would be required in the village.

The quotation was immediately withdrawn by the electricity supplier as they claimed they needed more information about the Combined Electric Primary Storage Unit.

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The Dilemma A major internal refurbishment program was

due to commence on the site at the beginning of January 2006. The work was to include kitchen and bathroom refurbishment, new central heating systems and electrical rewiring.

It quickly became clear that we would be unable to upgrade the electricity supplies in time.

By coincidence we acquired a HeatKing Air Source Heat Pump Brochure which under different circumstances may have been set aside.

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What caught our eye in the brochure was that even at an external temperature of -10 Deg C the coefficient of performance (COP) of the Heat Pump was 2 !!

HeatKing BWarm 8000 COPsAt Water Flow Temperature Of 50 DegC

0 5 10 15-15 -10 -51.5

2.0

2.5

3.0

3.5

4.0

4.5

Ambient Temperature (Deg C)

CO

P

50 DegC

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Cae Capel Bungalows:-Floor Plan

LIVING ROOM

KITCHEN

STOREBED 2

BED 1

BATHROOMA/C

HALL

ExternalStore

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Installation Of Air Source Heat Pump Central Heating At Cae Capel, Great Oak

Heat Loss And Radiator Selection

ROOM NAME Hall Lounge Cloaks Bath Bed 1 Bed 2 Kitchen TOTAL

ROOM HEAT LOSS Watts 507 1887 124 712 1064 664 1041 5999

Flow Temperature DegC 50 50 50 50 50 50 50

Return Temp DegC 45 45 45 45 45 45 45

Mean Temp DegC 47.5 47.5 47.5 47.5 47.5 47.5 47.5

Room Temp 18 21 18 22 18 18 21

D T Mean Temp Diff 29.5 26.5 29.5 25.5 29.5 29.5 26.5

Correction Factor @ DT 0.41 0.36 0.41 0.35 0.41 0.41 0.36

RADIATOR OUTPUT REQ. 1,223 5,191 299 2,055 2,567 1,602 2,864

DT Correction Factor

25DegC 0.338

30DegC 0.423

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HeatKing BWarm 8000 Pump Duty At Water Flow Temperatures Of 50 DegC

0 5 10 15-15 -10 -50

2

4

6

8

10

12

Ambient Temperature (Deg C)

Dut

y (K

W) 50 DegC

-3

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Locations Of Heat Pumps Must Be Located Outside Bolted Securely To A Wall Or Concrete Base Consider Effect On Circulation Routes Allow Adequate Room For Air Flow And

Maintenance Take Into Consideration Noise From Unit

(Provide screening etc. if necessary) Provide Soak away Or Drain For Condensate Avoid Long Pipe Runs (particularly external

runs) To The Unit.

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Clearance For Access and Good Air FlowHeatKing Bwarm8000

100mm Min

100mmMin

600mmMin

15

00m

m M

in

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CAE CAPEL, GREAT OAK

HP HP

HPHP HP579111315

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Schematic Of Air Source Heatpump At Cae Capel, Great Oak

Return

Flow

T T

T Thermostatic Radiator Valve

Pressure Differential Valve

Peglar Gate Valve Or Full Bore QT Valve

Peglar Full Bore PB 300T QT Valve with Stub Handle

s

s

s

s

s s

sWhere indicated with an s bends must be slowand preferably formed insitu where possibleAll bends to main flow and return to be slow

Drain off Cock

AirFlow

AirFlow

s

He

atk

ing

800

0

s

s

Hot Out SafetyValve

Cold In

Diverter Valve

s

p

Fill ing Loop

Expansion and Saftey Valve Kit

To Vent

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Approved installers, Installer Training All of the Heat Pumps we have installed have

been fitted by our own Corgi registered engineers.

The training requirements are relatively simple. We ran a 1 day installation training course for our engineers and supervising staff.

Our engineers are able to install the units and attend to minor faults but are not able to work on the refrigeration circuit.

Any faulty units are swapped over and returned to the manufacturer for repair. The manufacturer has provided us with a spare unit and provides a collection service.

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Typical Installation Costs Of Air Source Heat Pump Systems (2 Bed Bungalow) Heat pump £3500 Radiators and pipework £1450 Wiring & Controls CH & HW £550 Hot Water Cylinder £750 Builders Work £650

Total £6900

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Grants Currently there are no grants available

for Air Source Heat Pumps. VAT on the cost of the heat Pumps is 5% We have however received a one off grant

from the Welsh Assembly Government via the Home Energy Efficiency Scheme (HEES Wales) to extend our trial of Air Source Heat Pumps.

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Estimated Comparison of Energy Requirements, Cae Capel

Type Of SystemSAP

RatingRunning Cost *

Energy Requirement CO2

    £ GJ Kg

Electric Storage Radiators and Electric Immersion

Heater61 328 30.65 3525

Air Source Heat Pump& Electric Immersion

Heater67 286 16.69 1919

Calculated Using SAP 2001  Savings 42 13.96 1605

* Electricity Costs SWALEC 2005

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Estimated Running Costs Of Air Source Heat Pumps From Actual Meter Readings

Annual Electricity Costs Heating and Hot water

Actual Electricity Costs

Mar 2006-2007Estimated Non Heating &

HW (40% actual)Estimated Heating &

Hot water Only

£ £  £

338 lowest 135 203

600 240 360

390 156 234

569 228 341

725 highest 290 435

  Average Cost £315

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Air Source Heat Pump Reliability Fitted a total of 19 units since February 2006 3 Units failed to work on commissioning 1 Unit broke down within 7 days of installation 1 Unit broke down after 8 months running Of the 9 units fitted since last January none

have yet broken down, indicating that early reliability problems have been addressed

We keep a spare unit in store which can be swapped over

in a couple of hours. The faulty unit is then sent back to

the manufacturer in Yorkshire for repair

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Some Of The Advantages Of Air Source Heat Pumps Over Other

Systems Heat production is fully controllable Can be used on standard 60A electricity supplies No bulk storage of fuel is required 50-75% of energy produced is renewable * Sealed units mean no specialist knowledge

required Operation and Maintenance requirements are

very low Long life expectancy typically 20 years+ Low water temperature reduces risk of burning

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Some Of The Disadvantages Of Air Source Heat Pumps Over

Other Systems Installation costs are generally high External units are noisy and require careful sighting Capacity has to be very carefully matched to load Output decreases as external temperature decreases Radiator outputs need to be between 2-3 times

greater Unable to heat water and central heating at same

time Unable to fully heat hot water (efficiently) System needs to be filled with expensive antifreeze

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Schematic Diagram Of Central Heating Only Air Source Heat Pump Installation

Return

Flow

T T

T Thermostatic Radiator Valve

Pressure Differential Valve

Peglar Gate Valve Or Full Bore QT Valve

Peglar Full Bore PB 300T QT Valve with Stub Handle

ss

s

s

s s

s Where indicated with an s bends must be slowand preferably formed insitu where possibleAll bends to main flow and return to be slow

Drain off Cock

AirFlow

AirFlow

s

p

Fill ing Loop

Expansion and Saftey Valve Kit

2KW In LineElectric WaterHeaterOnly Used On SystemsBetween 6-8KW

He

atk

ing

800

0

s

s

Safety Valve

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What Is An Air Source Heat Pump ?

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Coefficient Of Performance

The coefficient of performance of a heat pump is the ratio of energy given out to the electrical energy put in.

For a heat pump with a COP of 3 you would expect to get 3KW out for every 1KW you put in.

1 KW would come from electricity and 2KW would come from heat extracted from the air.

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Coefficient Of Performance Against Ambient Temperature

HeatKing BWarm 8000 COPsAt Water Flow Temperatures Of 35 & 50 DegC

0 5 10 15-15 -10 -51.5

2.0

2.5

3.0

3.5

4.0

4.5

Ambient Temperature (Deg C)

CO

P

50 DegC

35 DegC35 DegC

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What Is An Air Source Heat Pump ?