Transcript Air Source Heat Pump Presentation

Air Source Heat Pump
Presentation
Andrew Knill
Monmouthshire County Council
1
What Made Us Consider Air
Source Heat Pumps?
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Increased Number Of Complaints From Tenants
About Their Solid Fuel and Electric Storage Radiators
Systems.
Sharply Rising Cost Of Oil (Winter 2005)
2
Solid Fuel Complaints
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Older Tenants: Unable To Carry Coal and Ashes
Quite Expensive To Run
Home Help Often Required.
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Younger Tenants:
Unable To Control System.
High Running Costs.
Dirty To Operate.
Danger To Children.
3
Electric Storage Radiator Complaints
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Unable To Control:
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High Running Costs.
Too Hot In The Night and The
Morning.
No Heat Left By The Evening.
4
Monmouthshire County Council
Breakdown of Heating Fuel Types
January 2005
Number Of Properties
Gas
Oil
Solid Fuel
Electric
3045
58
227
310
3640
Percentage
84
2
6
9
15%
5
Cae Capel, Great Oak, Near Raglan.
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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.
6
7
8
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The tenants wanted LPG or Oil Heating.
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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.
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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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10
11
15
13
11
9
7
5
CAE CAPEL, GREAT OAK
12
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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.
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The units chosen were the Gledhill Electomate 2000’s
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The systems were to use Tariff 10 electricity.
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The tenants were to be set up on the Easy Warm
scheme to ensure their fuel bills were capped and
affordable.
13
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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.
14
The Dilemma
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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.
15
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 COPs
At Water Flow Temperature Of 50 DegC
4.5
4.0
COP
3.5
50 DegC
3.0
2.5
2.0
1.5
-15
-10
-5
0
5
10
15
Ambient Temperature (Deg C)
16
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Cae Capel Bungalows:-Floor Plan
KITCHEN
LIVING ROOM
External
Store
A/C
BATHROOM
HALL
BED 1
BED 2
STORE
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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
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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
12
Duty (KW)
10
50 DegC
8
6
4
2
0
-15
-10
-5
-3
0
5
10
15
Ambient Temperature (Deg C)
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Locations Of Heat Pumps
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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.
20
Clearance For Access and Good Air Flow
HeatKing Bwarm8000
100mm
Min
100mm Min
1500mm Min
600mm
Min
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22
23
HP
HP
15
13
11
HP
9
HP
7
5
HP
CAE CAPEL, GREAT OAK
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Schematic Of Air Source Heatpump At
Cae Capel, Great Oak
Drain off Cock
T
Thermostatic Radiator Valve
Peglar Full Bore PB 300T QT Valve with Stub Handle
Air
Flow
Peglar Gate Valve Or Full Bore QT Valve
Expansion and Saftey Valve Kit
Heatking 8000
Air
Flow
Pressure Differential Valve
s
s
To Vent
s
p
Filling Loop
Flow
Where indicated with an s bends must be slow
and preferably formed insitu where possible
All bends to main flow and return to be slow
Diverter Valve
SafetyValve
Hot Out
s
s
s
s
s
Re tu rn
T
s
T
s
Cold In
s
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Approved installers, Installer Training
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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)
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Heat pump
Radiators and pipework
Wiring & Controls CH & HW
Hot Water Cylinder
Builders Work
£3500
£1450
£550
£750
£650
Total £6900
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Grants
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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 System
SAP Running
Energy
Rating Cost * Requirement
CO2
£
GJ
Kg
Electric Storage Radiators
and Electric Immersion
Heater
61
328
30.65
3525
Air Source Heat Pump
& Electric Immersion
Heater
67
286
16.69
1919
Calculated Using SAP 2001
Savings
42
13.96
1605
* Electricity Costs SWALEC 2005
33
Estimated Running Costs Of Air Source Heat Pumps
From Actual Meter Readings
Annual Electricity Costs Heating and Hot water
Actual Electricity
Costs
Estimated Non Heating &
Mar 2006-2007
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
34
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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35
Some Of The Advantages Of Air Source
Heat Pumps Over Other Systems
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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
36
Some Of The Disadvantages Of Air
Source Heat Pumps Over Other Systems
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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
37
Schematic Diagram Of Central Heating
Only Air Source Heat Pump Installation
Expansion and Saftey Valve Kit
Drain off Cock
T
p
Air
Flow
Peglar Full Bore PB 300T QT Valve with Stub Handle
Safety Valve
Air
Flow
Thermostatic Radiator Valve
Peglar Gate Valve Or Full Bore QT Valve
Heatking 8000
Filling Loop
Pressure Differential Valve
s
s
s
Where indicated with an s bends must be slow
and preferably formed insitu where possible
All bends to main flow and return to be slow
Flow
2KW In Line
Electric Water
Heater
Only Used On Systems
Between 6-8KW
s
s
s
s
Re tu rn
T
s
T
s
s
38
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What Is An Air Source Heat Pump ?
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Coefficient Of Performance
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The coefficient of performance of a heat pump is the
ratio of energy given out to the electrical energy put in.
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For a heat pump with a COP of 3 you would expect to
get 3KW out for every 1KW you put in.
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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 COPs
At Water Flow Temperatures Of 35 & 50 DegC
4.5
35 DegC
4.0
COP
3.5
50 DegC
3.0
2.5
2.0
1.5
-15
-10
-5
0
5
10
15
Ambient Temperature (Deg C)
42
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What Is An Air Source Heat Pump ?
43