Air
Source Heat Pumps
Presentation
Heading
Jordan
Jeewood
Heating Technical Executive
What is an Air Source Heat Pump?
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
Air @ -5ºC
Water @ 58ºC
What is an Air Source Heat Pump?
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
450
400
400
350
350
% Efficiency
300
250
200
150
99
93
91
86
Direct
Electric
Gas
LPG
Oil
100
50
0
Ground
Source
Air Source
Heat pump technology
 Inverter driven compressor and fan
 Weather compensation
 These technologies lead to greater efficiencies
Inverter
Compressor
Inverter
control
PCB
Inverter Drive Technology
Duty (kW)
Heat load
Fixed speed
Inverter
10
5
0
Time
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
Potentially
over 16
million homes
are suitable –
new build and
retrofit
14kW
8.5kW
5kW
2 Bed Flat
3 Bed Semi
4 Bed Detached
Scalability
Geographically and
seasonally independent
Manufactured in Scotland
National distribution network
– already in place through
aircon
Supporting Approved Ecodan
Installers all over UK
Grid
Future proof
Hot Water
Turbine
Radiators
mCHP
PV
Under floor
Heating
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
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
DHW cylinder supplying
shower etc.
Heat pump positioned
externally
Supplies space
heating via
underfloor or rads
Applying Air Source Heat Pumps
S Plan System
All fitting on cylinder package
Zone
valves
Pump
Flow
setter
Boiler
buddy
Pump
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
Heat Loss of a Dwelling
Victorian House
1970’s House
2006 House
Minimum boiler
output = 10.8kW
Minimum boiler
output = 6.6kW
Minimum boiler
output = 3.9kW
All 80m2 floor space, similar shape and -3oC outside, 22oC inside
Emitter Selection
3 Points to consider:
Desired Room
Temperature = 20oC
1. Water flow temperature
through emitter
2. Peak heat loss of room
3. Space to locate emitter
Mean Water Flow
Temperature = 40oC
Applying Air Source Heat Pumps
 Site survey is
required for
accurate heat
loss calculation
Thank you
Discussion