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PresentationHeadingJordan Jeewood
Heating Technical Executive
Air Source Heat Pumps
What is an Air Source Heat Pump?
Refrigeration circuit used to heat water – fridge in reverse
Sealed refrigerant unit outputs hot water – outdoor unit
Plate heat exchanger transfers energy from hot refrigerant to water
What is an Air Source Heat Pump?
Produces hot water 25-58ºC – heating only
5kW, 8.5kW, 14kW Mitsubishi Electric Ecodan – domestic market
No need for refrigeration qualification to install
Approved Ecodan Installers – plumbers and heating engineers
What is an Air Source Heat Pump?
Air @ -5ºC Water @ 58ºC
R410A refrigerant
Very efficient way to heat water ~ 300-400%
For every 1 unit of energy put in, 3 useful units of energy out – high COP
What is an Air Source Heat Pump?
400
350
99 93 91 86
0
50
100
150
200
250
300
350
400
450
GroundSource
Air Source DirectElectric
Gas LPG Oil
% E
ffic
ien
cy
Inverter driven compressor and fan
Weather compensation
These technologies lead to greater efficiencies
Heat pump technology
Inverter Compressor
Inverter control PCB
Heat load
Fixed speed
Inverter
Duty (kW)
Time
10
5
0
Inverter Drive Technology
Weather Compensation
Heat load of property reduces as ambient temperature increases
Weather Compensation
Reducing flow temperature matches output of boiler to heat load
Weather Compensation
Heat pump has to draw less power to output lower flow temperatures
COP increases
Weather Compensation
UK Market Size – Domestic Heating
60 million people
26 million homes
1.6 million heating systems replaced / yr
85% gas boilers
4.5 million homes – off gas grid
4.7 million social housing
Why now?
Cost effective
Reliable and maintainable as existing systems
“Scalable” solution that can be easily “adapted” for the whole country
Future proof
Has to be absolutely acceptable to homeowners in terms of space, noise and usability
Cost effective
Payback period typically 5-10 years compared to oil, LPG, electricity
Payback period will decrease as:
Fossil fuels increase in price
The Technology becomes more commoditized
Manufacturing costs are decreased through economies of scale
Introduction of Renewable Heat Incentive (2012)
Reliability & Maintainability
Proven technology – air conditioning units used for years
Minimal servicing needed – like a fridge
Essentially a visual inspection, heat exchanger to be kept clean
Hot water to clean the coil and brush to remove debris e.g. leaves
Scalability
2 Bed Flat 3 Bed Semi 4 Bed Detached
5kW
14kW
8.5kW
Potentially over 16
million homes are suitable – new build and
retrofit
Scalability
Geographically and seasonally independent
Manufactured in Scotland
National distribution network – already in place through aircon
Supporting Approved Ecodan Installers all over UK
Grid
PV
Turbine
mCHP
Future proof
Hot Water
Radiators
Under floorHeating
Acceptable to homeowners
No change in lifestyle or comfort level
Capable of providing both heating and hot water requirements for a property all year round – tank can be heated to 55ºC
Radiators and underfloor heating
Use of standard domestic heating controls
Quiet unit operation – typically 48dBA
Applying Air Source Heat Pumps
Radiators or underfloor heating can be used
Heating and hot water separate – S Plan plumbing
Integrated like conventional boiler system
Heat pump positioned externally
DHW cylinder supplying shower etc.
Supplies space heating via underfloor or rads
Applying Air Source Heat Pumps
Zone valves
PumpBoiler buddy
Flow setter
Pump
S Plan System
All fitting on cylinder package
Applying Air Source Heat Pumps
Principals of Heat Pump Sizing
Heat Loss from Dwellings:
Fabric Heat Loss
Ventilation Heat Loss
Heat pump should be sized on peak heat loss of dwelling
Victorian House
Minimum boiler output = 10.8kW
1970’s House
Minimum boiler output = 6.6kW
2006 House
Minimum boiler output = 3.9kW
All 80m2 floor space, similar shape and -3oC outside, 22oC inside
Heat Loss of a Dwelling
3 Points to consider:
1. Water flow temperature through emitter
2. Peak heat loss of room
3. Space to locate emitter
Desired Room Temperature =
20oC
Mean Water Flow Temperature = 40oC
Emitter Selection
Site survey is required for accurate heat loss calculation
Applying Air Source Heat Pumps
Thank you
Discussion
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