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