Air & Ground Souce Heat Pumps
Air Souce Heat Pump
What is it?
Air source heat pumps absorb heat from the air around
you. They can extract heat from the air even when the outside
temperature is as low as minus 15oC, however they generally perform
better at warmer air temperatures.
How does it work?
- An air source heat pump extracts heat from the outside air in
the same way that a fridge extracts heat from its inside.
- Heat from the air is absorbed into a fluid which is pumped
through a heat exchanger in the heat pump. Low grade heat is then
extracted by the refrigeration system and, after passing through
the heat pump compressor, is concentrated into a higher temperature
that is capable of heating water for the heating and hot water
circuits of the house.
There are two main types of air source heat pump system:
- An air-to-water system distributes heat via your wet central
heating system. Heat pumps work much more efficiently at a lower
temperature than a standard boiler system would, so they are more
suitable for underfloor heating systems or larger radiators (that
give out heat at lower temperatures over longer periods of
time).
- An air-to-air system produces warm air which is circulated by
fans to heat your home. However, they are unlikely to provide you
with hot water as well.
Is it suitable?
The unit can be fitted to an outside wall or stood on the
ground. It should be sited where there is plenty of space around it
to ensure a good flow of air. A sunny wall is ideal. Heat pumps are
not recommended for homes on the gas network.
As air source heat pumps produce heat at a lower temperature
than traditional boilers, it's essential that your home is well
insulated and draught proofed.
Ground source Heat Pumps
What are the benefits?
- The system will pay for itself much more quickly if it's
replacing an electricity or coal heating system.
- No fuel deliveries required.
- Can provide space heating and hot water.
- It’s often classed as a ‘fit and forget’ technology because it
needs little maintenance.
- Can be easier to install than a ground source heat pump, but
efficiencies can be lower.
- Heat pumps have some impact on the environment as they need
electricity to run, but the heat they extract from the air (ground)
is constantly renewed naturally.
- Ground Source Heat Pump
- What is it?
- Ground source heat pumps use the constant temperature of the
soil at 1 metre below the surface as their heat source.
How does it work?
A ground source heat pump circulates a mixture of water and
antifreeze around a loop of pipe - called a ground loop - which is
buried, or alternatively via a bespoke borehole in the garden. Heat
from the ground is absorbed into this fluid and is pumped through a
heat exchanger in the heat pump. Low grade heat passes through the
heat pump compressor and is concentrated into a higher temperature
that is capable of heating water for the heating and hot water
circuits of the house. After circulation, the cooler fluid
passes back through the loop into the ground where it absorbs
further energy from the ground in a continuous process while
heating is required.
Is it suitable?
Your garden doesn’t have to be particularly large, but the
ground needs to be suitable for digging a trench or a borehole and
accessible to digging machinery.
Since ground source heat pumps produce a lower temperature heat
than traditional boilers, it's essential that your home is well
insulated and draught proofed to ensure maximum effectiveness of
the heating system.
Underfloor heating systems, larger radiators or low temperature
fan convectors (warm air heating) perform better than standard
radiator-based systems because of the lower water temperatures
required.
What are the benefits?
- Radiators will operate at lower surface temperatures than when
connected to a conventional gas/ oil fired heating system. As
heat pumps deliver their heat at lower temperatures, it is often
necessary to run the heating system for longer periods to heat your
home efficiently. The system will pay for itself much more quickly
if it's replacing an electricity or coal heating system.
- No fuel deliveries required.
- Can provide space heating and hot water.
- It’s often classed as a ‘fit and forget’ technology because it
needs little maintenance.
- Heat pumps have some impact on the environment as they need
electricity to run, but the heat they extract from the air (ground)
is constantly renewed naturally.
Contact Us
Climate Change Officer
Property, Leisure and Waste Management
White Cliffs Business Park
Whitfield
Dover
Kent CT16 3PJ
Email: energy@dover.gov.uk
