What are the disadvantages of an air source heat pump?

The COP of an air source heat pump falls in cold weather, just when most heat is needed. The outdoor unit makes fan noise and must defrost itself in icy conditions.

What are the advantages of an air source heat pump over a ground source heat pump?

An air source heat pump is cheaper and quicker to install, because no digging or drilling is needed. An air source unit also suits homes with little or no garden.

Compare air source and ground source heat pumps.

Ground source heat pumps are more efficient and quieter because the ground is warmer than winter air. Air source heat pumps cost much less to install and need little space.

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Microgeneration

Topic overview Microgeneration technologies Benefits of home and community microgeneration The heat pump cycle and coefficient of performance Air source and ground source heat pumps

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Microgeneration

Air source and ground source heat pumps

3 things to know
AS 1

Overview

How air source and ground source pumps work and compare, closed and open loops, horizontal, vertical and pond loops, slinky coils, emitters, a running-cost comparison with oil, and matching a pump to a home.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Process

How does an air source heat pump work?

Process

How does a ground source heat pump work?

Key term

Why does a ground source heat pump usually achieve a higher COP than an air source heat pump?

Questions from this subtopic

Each one with the model answer underneath.

1
How does an air source heat pump work?
Model answer
A fan draws outside air across the evaporator, where the refrigerant absorbs heat from it. The heat is upgraded by the compressor and delivered to radiators, underfloor heating or hot water.
2
How does a ground source heat pump work?
Model answer
A mixture of water and antifreeze circulates through pipes buried in the ground and absorbs heat. The heat pump upgrades the collected heat and delivers it to the home.
3
Why does a ground source heat pump usually achieve a higher COP than an air source heat pump?
Model answer
A few metres down, the ground stays at a fairly steady temperature of around 10°C all year. Winter air is much colder, so an air source pump must lift heat through a larger temperature rise.
4
What are the disadvantages of an air source heat pump?
Model answer
The COP of an air source heat pump falls in cold weather, just when most heat is needed. The outdoor unit makes fan noise and must defrost itself in icy conditions.
5
What are the advantages of an air source heat pump over a ground source heat pump?
Model answer
An air source heat pump is cheaper and quicker to install, because no digging or drilling is needed. An air source unit also suits homes with little or no garden.
6
Compare air source and ground source heat pumps.
Model answer
Ground source heat pumps are more efficient and quieter because the ground is warmer than winter air. Air source heat pumps cost much less to install and need little space.

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Fossil Fuels

Global Action on Energy Conservation and Climate Change

Macrogeneration

Microgeneration

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