Pool Air Source Heat Pump
Air source heat pumps are an ultra-efficient, economical and
"green" way to heat swimming pool water. In fact, air source heat
pumps have the lowest carbon footprint and lowest operating costs compared to
other heating methods. For the most modern, efficient, reliable and
environmentally friendly heating of your swimming pool, we do not hesitate to
recommend our low cost air source heat pumps.
How does a pool heat pump work?
Swimming pool heat pumps do not generate heat directly, they use a small
amount of electricity to capture the abundant heat in the air and transfer it
efficiently to the water in the pool.
The heat pump, combined with the pool filtration and pumping system,
circulates, cleans and heats the pool's water through the sand filter and then
through the heat pump heat exchanger. Heat pump heaters contain a fan that
draws in outside air and directs it over the evaporator coil radiator. The
evaporator coil contains a liquid refrigerant that absorbs heat from the
outside air and converts it into a gas. The hot gas in the coil passes through
the compressor. The compressor then adds heat, producing extremely hot gas,
which then passes through the condenser. The condenser then transfers heat from
the gas to the cooler pool water, which circulates through the heat pump pool
heater. The heated water is then returned to the pool. As the hot gas flows
through the condenser coil, it cools rapidly and returns to the evaporator,
returning to liquid form. Then the whole process starts all over again.
How long does it take for a heat pump to heat a swimming pool?
A properly sized heat pump will usually heat the pool in about 4 to 5
days.
However, you can use the following formula to get a more accurate
estimate for a specific pool:
Seconds = liter x 4.18 (specific heat capacity of water) x temperature
difference/kW
So if you have a 12kW heat pump on an 8m x 4m x 1m (average depth)
swimming pool and you want to heat it to 25 degrees (assuming 5 degrees cold
water) then the calculation is as follows:
Seconds = 32000 x 4.18 x 20 ÷ 12
This equals 222, 933 seconds or 62 hours
This does not take into account any heat loss during heating and
therefore needs to be added.
How efficient is a swimming pool heat pump?
A dedicated swimming pool air source heat pump can actually be around
500% efficient, which means it will generate 5 kWh of heat for every kWh of
electricity it uses. The efficiency of the heat pump is proportional to the
ambient temperature of the air and the target temperature of the water. The
farther apart these two temperatures are, the lower the efficiency
There are some reasons for and against the use of heat pumps as a source
of heat for swimming pools.
On the plus side, heat pumps use electricity, so you can use the
electricity generated from the photovoltaic panels to power the heat pump.
They are also very efficient, and for every 1kWh of electricity you
consume, you have the potential to gain 5kWh of heat.
However, swimming pools require a lot of energy to heat, so you need to
make sure your home's electricity supply is sufficient for the extra load of
pool heating.
Heat pumps are not as fast as heating pool water compared to fossil fuel
heaters and may have noise associated with air source heat pumps
What size heat pump do I need for my swimming pool?
The size of the pool and heat loss needs to be defined, then a suitable
heat pump is specified to make up for the heat loss, and it also has the
ability to reheat the pool if you allow it to cool seasonally.
Many swimming pool circulators will run about eight hours a day. The
heat pump should be able to deliver the required heat to the pool during these
times. If reheating is required, the pool pump runs longer. Indoor pools have
lower heat loss than outdoor pools, but with indoor pools, you also need to
allow the air in the billiard room to be heated and circulated. The air
temperature is usually kept about 3 degrees warmer than the water temperature
to mitigate evaporative losses.
Air circulates at a much higher rate than is required in a domestic home,
so standard Mechanical Heat Recovery Ventilation (MVHR) units are not suitable
for this purpose. A dedicated pool ventilation unit is required, and these
typically also manage heat transfer to the air and pool water.
How much does a heat pump for a swimming pool cost?
Dedicated swimming pool heat pumps can be much less expensive than air
source heat pumps, which are often attached to our homes for central heating
and hot water production.
Dedicated swimming pool heat pumps start at around £1,500, but for a
complete air handling unit with thermal management you may need upwards of
£15,000.
Do your research and identify your needs, as costs can quickly escalate.
The running cost of heating a swimming pool with a heat pump:
The running cost of a swimming pool heat pump will be proportional to
the heat loss from the water.
Heat loss in outdoor pools is usually much higher than in indoor pools
due to evaporative losses, lack of insulation and exposure to cold winds.
As a very general guide, look at the surface area in square meters, then
use about 200W per square meter for a bare outdoor pool to about 50W per square
meter if the pool is in a protected location with good thermal coverage.
If the air in the billiard room is warmer than the water, the indoor pool
will lose less heat. This air heat loss should be included in the running cost
of swimming pool heating.
Swimming pool heat pump installation:
Heat pumps are best installed outdoors. If installed indoors, they must
have adequate and unrestricted outside air circulation. They must be installed
and commissioned by a qualified technician in accordance with current
regulations. It is recommended that you check that your power supply supports
your preferred power input before ordering. Test your water regularly to avoid
acid or limescale damage that could void your warranty. Heat pumps must operate
within their seasonal and waste flow design limitations.
Heat Pump Power Output Guidelines:
As long as you keep the pool covered when not in use, these should be
able to provide you with a comfortable swim throughout a typical UK open-air
swimming season.
In Ground Pools
|
Pool size |
Power / kW |
|
24ft x 12ft (7.32m x 3.66m) |
12 - 16 |
|
28ft x 14ft (8.53m x 4.27m) |
12 - 16 |
|
30ft x 15ft (9.14m x 4.57m) |
15 - 25 |
|
32ft x 16ft (9.75m x 4.88m) |
23 - 31 |
|
36ft x 18ft (10.97m x 5.49m) |
23 - 31 |
|
40ft x 20ft (12.19m x 6.10m) |
30 - 36 |
Above Ground Pools:
|
Pool size |
Power / kW |
|
12ft diameter (3.66m) |
8 - 12 |
|
15ft diameter (4.57m) |
9 - 16 |
|
18ft diameter (5.49m) |
9 - 16 |
|
20ft x 12ft (6.10m x 3.66m) |
9 - 16 |
|
24ft x 12ft (7.32m x 3.66m) |
15 - 18 |
|
30ft x 15ft (9.14m x 4.57m) |
15 - 25 |
|
33ft x 18ft (10.06m x 5.49m) |
23 - 31 |
