The benefits of heat pumps include cost savings on heating bills and lower carbon emissions, which can ease the pressure on household finances during the current energy crisis and reduce the effects of climate change.
Heat pumps have hit the news recently, with the UK Chancellor announcing the abolition of VAT on the installation of these and other energy saving measures.
The pressure is on to find ways for the UK to meet its ambitious target of cutting carbon emissions by 78% by 2035 compared to 1990 levels. Just 15 years beyond that, there is a further target to meet net zero carbon emissions by 2050.
A key part of the plan to hit these targets is the installation of 600,000 heat pumps per year, making households and businesses more energy efficient and creating a quarter of a million new green jobs in the process.
But what is a heat pump and what are the likely benefits of installing one? Let’s take a look.
What is a heat pump?
A heat pump is a piece of kit that moves heat from outside your home to inside. It does this in the same way that an air conditioning unit cools your home, except in reverse. In fact, you can buy heat pumps that perform both these functions, providing heating during the winter and cooling during the summer.
Heat pumps make use of a refrigerant, which collects heat from outside using a heat exchanger. In the case of an air source heat pump, the refrigerant is pumped through evaporator coils on the outside unit, across which air is blown by a fan. The refrigerant is then compressed, which in effect concentrates the heat before passing through the condenser, where the heat is released from the refrigerant fluid and used to heat the home.
Heat pumps come in three main types, according to where they source their heat.
- Air source – the most common type, which get heat from the air outside the property.
- Ground source – slightly more efficient than air source but require trenches or boreholes for the heat collector to be buried in.
- Water source – often the most efficient type, but requires a pond, loch or nearby river in which to lay the pipework.
Despite being a well-established technology – the first development of the idea by Lord Kelvin dating back to 1852 – heat pumps have not been widely taken up as a means of heating in the UK. This is set to change in the coming years as we get serious about playing our part in addressing the global climate emergency.
So, what are the benefits of a heat pump?
There are many benefits to installing a heat pump, some obvious and some less so. Let’s start with the most obvious.
The efficiency of heat pumps is typically 3 to 4 times greater than equivalent electrical resistance heating. This is because heat pumps move heat from one place to another, rather than generating heat directly using electrical resistance.
For every unit of electrical energy used by a heat pump, 3 or 4 units of heat energy are made available. The exact ratio is specified in the Coefficient of Performance (COP).
A COP of 1.5 to 3 is typical for an air source heat pump and this figure is even higher for ground source and water heat pumps, which are normally even more efficient and can achieve COP of 2.5 to 3.
Heat pumps are most efficient when the temperature difference between the outside air and the interior of the building is smallest. The temperature underground or underwater remains relatively stable throughout the year, which is why ground source and water source heat pumps are more efficient during the winter when air source heat pumps need to work harder to collect heat from the colder air above ground.
Ground source heat pumps tend to be more expensive to install, because they require the digging of trenches or a vertical borehole in which to bury the ground loop. This means that the payback period for the initial investment of a ground source heat pump takes longer, but once the system has broken even it will save more money overall than even the best air source heat pump.
The same is true for a water source heat pump because of the extra work and expense to secure the pipework at the bottom of the body of water.
Heat pumps do not rely on the householder burning fuel to generate heat. They are therefore cleaner than open fires or woodburning stoves, which pollute the local environment with smoke.
Wood burning stoves are very popular these days but often result in poor air quality in areas where they are widely used. Coal fires are even worse – remember the stories of smog in built up areas during the last century when coal was the fuel of choice? That’s not something anyone wants to go back to.
Inside the home as well, there is often escape of smoke into living areas, particularly if the flue becomes fouled with soot or is not correctly designed or fitted. Even a gust of wind in the wrong direction can cause smoke to blow into the room in some cases.
It’s not just fireplaces that cause poor air quality either. There are many sad cases of carbon monoxide poisoning because of badly maintained gas boilers and fires. There are no such concerns with heat pumps.
A heat pump can save you money thanks to its superior efficiency, but did you know that there are incentive schemes available that can help with the cost of installing a heat pump?
Although the domestic Renewable Heat Incentive (RHI) ended on 31 March 2022, the new Boiler Upgrade Scheme (BUS) is available in England and Wales to help with the costs of installing low carbon heating. A similar scheme is anticipated for Scotland, although an announcement about this is yet to be made.
The zero VAT measure announced by the Chancellor will also help to minimise the cost of installing a heat pump.
Better for the planet
Heat pumps are more efficient than other forms of heating, which not only saves you money but is better for the planet. The higher efficiency means that less harmful CO2 gas is emitted as a result of heating your home.
In fact, if renewable electricity is used to power your heat pump, you could heat your home with no carbon emissions at all.
Heat pumps are an important piece of the UK’s energy strategy as we move towards our target of net zero carbon emissions by 2050. They are a highly efficient means of heating our homes and offices and offer benefits in terms of cost savings and good air quality in addition to the lower carbon emissions we need now and in the future.
With the financial incentives available to help with the cost of installation, now is a good time to consider installing a heat pump to heat your property.