|
|
WHAT IS A HEAT PUMP?
Traditional central heating relies on burning gas to heat up water, then circulates
the water around your home into radiators that give out heat to your rooms.
Instead of burning fuel directly to create heat, heat pumps extract energy from
the heat that exists all around us and use it to warm our homes and heat up domestic
hot water.
There are two main types of heat pump. Those that extract heat from the air and those
that take it from the ground.
Each type of pump has its own advantages and disadvantages (more about these later),
but both types work incredibly efficiently, typically turning each £1 you spend on
fuel into £3 or more of heat.
WHERE DOES THE HEAT ENERGY COME FROM?
Heat pumps absorb solar energy trapped in the air and in the ground.
Even on cloudy days, heat from the sun warms the air and the ground (particularly
the ground where, below the surface, the temperature remains warmer than above-ground
even in winter).
We can tap into these heat sources using technology to harness the warmth they contain.
HOW DO HEAT PUMPS WORK?
There are two types of heat pump - air to water and ground to water, known respectively
as 'air source' and 'ground source'.
Air Source Heat Pumps
These work by taking the principle of the refrigerator and turning it inside out.
In a refrigerator, a special gas is pumped through pipework around the shell of the
fridge. The gas absorbs heat from inside the refrigerator then disperses this heat
into the surrounding air at the back of the fridge.
As a result, the refrigerator is cooler inside than it is outside.
With your home, an air source heat pump takes heat from the outside air (even on a
cold day) then transfers this heat to water so the heated water can be pumped
around your home, creating a warm home and providing hot water.
Ground source heat pumps
In ground source heat pumps, warmth trapped underground is absorbed into water circulating
through underground pipes and this warmed water is then brought to the surface.
The heat energy in the warmed water is transferred to water circulating around the
home to provide warmth and to heat up domestic hot water. |
|
WHY ARE HEAT PUMPS SO EFFICIENT?
Because the source of heat is free (energy in the air or the ground), a heat pump
is an extremely efficient way of creating warmth.
The main operating cost of a heat pump is the electricity used to pump the heat source
(air or water) into the heat pump and the heated water around your home.
HEAT PUMP ADVANTAGES AND DISADVANTAGES
Efficiency
The key advantage of heat pumps is their operating efficiency - typically £1 of energy
put into the pump generates £3 or more of heat energy for your home.
Costs
Heat pumps are currently more expensive to buy and install than traditional boilers.
The higher installation costs have to be taken into account when considering the benefits
of choosing a heat pump over a traditional gas fuelled boiler if your home already
has a mains gas supply.
If you can't connect to mains gas then heat pumps become much more attractive in comparison
to the alternatives of oil or LPG due to the installation costs of fuel storage and
a boiler.
In addition, heat pumps are eligible at the moment for financial
incentives which can help with installation and running costs.
Practicalities
Typically, heat pumps produce heated water at around 45-55oC, fine for
underfloor heating, but below that required for traditional radiator based heating
and for providing domestic hot water.
As a result, whilst radiators can still be used with heat pumps they need to be bigger
than normal to provide enough heat to a room.
This is because the surface temperature of a radiator on a heat pump system is lower
than in gas powered heating.
Also, the temperature of the domestic hot water provided by a heat pump needs to be
boosted by a secondary heat source (such as an immersion heater) to make it usable.
The hot water storage cylinder temperature also needs to boosted regularly to around
65oC to prevent the growth of Legionella bacteria
in the cylinder.
Still confused about heat pumps?
We're qualified in heat pump installation, servicing and repairs, so call or e-mail us
now for more advice or a free home survey. |
|