Heat Pump FAQS

Heat pumps provide an alternative way of heating our home or business, offering us the chance to cut down on our carbon footprint and also reduce our energy bills. The two most widely used types of heat pump are air-source (or ‘air-to-water’) and ground-source (or ‘geothermal’) heat pumps.

What all heat pumps have in common is that they extract heat from natural sources, such as the air or the ground, which they then use to provide hot water and central heating to our property.

Unlike boilers, heat pumps are located outside, with many fixed on an external wall or placed securely on the ground outside the property.

Heat pumps absorb warmth from sources of heat including the air, ground and bodies of water. They do this by transferring the heat to a liquid (called a ‘refrigerant’), which circulates through a looped system of pipes. As it heats up it becomes a gas and the Heat pump systems then use a compressor which heats this gas up by increasing its pressure.

The hot gas then transfers its heat to the water in your system through a heat exchanger, it’s then able to provide the heating we need, for radiators, hot water and other heating like underfloor heating.

Heat pumps are very efficient central heating solutions that use naturally occurring heat to provide us with hot water and heating. An air-source heat pump can produce as much as four units of heat for every unit of electricity it uses.

Air-source heat pumps will not be able to perform to their full efficiency if the temperature outside is cooler, but even then they’ll still produce more units of heat than the units of electricity they use. Because they’re so good at increasing the temperature of the heat they absorb, they can still provide the warmth to heat our property in temperatures as low as -20 °C.

Ground-source heat pumps are often more efficient than air-source heat pumps but they are also more costly and complicated to install.

The biggest advantage of installing a heat pump is that it’s much more energy efficient than traditional central heating systems, even modern condensing gas boilers. This means they will have a positive impact on both your carbon footprint and your energy bills.

They are easy to install, although fitting a ground-source heat pump takes longer than an air-source heat pump because it involves burying pipework in the ground.

A ground-source heat pump is also known as a geothermal heat pump. It works by absorbing natural heat from the ground into a ‘ground loop’ of buried pipes, before transferring that energy to provide hot water and central heating.

When considering installing a ground source heat pump one could choose between a network of horizontal collectors laid in the immediate proximity to the ground’s upper layers at small depths, or opt for vertical ground source heat pump boreholes instead, which is also known as vertical closed-loop geothermal heat exchangers. Selecting between these two systems, conceptually similar but structurally different, comes down to the available space for a geothermal pump installation, the square footage that requires heating and the budget allowance one can sanction for carrying the installation works.

Vertical boreholes are good for small or limited areas, and although it bears high installation costs, borehole heat collectors produce a higher heat yield per metre, compared to horizontal collectors, which entails a better energy efficiency rate. Thus, if you are considering drilling a borehole, you will have to make sure that the ground is suitable for digging a deep-seated ditch and that the designated area is accessible for fitting in the drilling equipment.

A third and less common type of heat pump system is the water-source heat pump. These heat pumps work similarly to ground and air-sources systems, with the main difference being that they extract heat from bodies of water to power heating and hot water.

Heat pumps are designed to run efficiently all year round and are well equipped to run in cold temperatures. Some heat pumps can continue working in outside temperatures of -20°C and will run defrosting cycles in very cold weather to make sure they continue working properly.

The average lifespan of a heat pump is roughly 15 years, which is around the same length of time as a modern gas boiler. Newer heat pump models may actually continue to work efficiently for even longer and could possibly last up to 25 years.

By keeping your heat pump well maintained you will help it work more efficiently and last longer, so it’s always worth taking good care of it, which can include annual checks from qualified engineers.

It’s recommended that you have your heat pump serviced at least once a year by a heating engineer to make sure it’s running efficiently. It will also mean the system is checked for problems, so any issues can be discovered and fixed quickly before they get worse.

Finding problems with your heat pump early can help prevent them from causing larger issues that could be more expensive to fix further down the line.

Heat pumps will work with the existing wet distribution system but there will be more than likely a need to increase the size of your current radiators to maximise the available surface area. A heat pump engineer will be able to help you understand whether any changes are necessary. Heat pumps also work very efficiently with under floor heating, which could be another option.

If the outside of your heat pump unit needs cleaning, turn off the power to the appliance before wiping it down with a non-abrasive cloth and warm water. If you notice a build up of leaves or debris around the outdoor unit, you can carefully brush them away.

If you think there’s a technical problem with your heat pump unit you should never try to clean it out or fix it yourself. By having your heat pump serviced at least once annually by a qualified engineer, you can make sure that any potential issues are spotted and resolved quickly.

The size of the heat pump you’ll need for your property depends on factors including how large your property is and the size of its radiators. If the heat pump is too small it won’t provide the amount of heat you need, while if it’s too large that could also cause issues.

An oversized heat pump can ‘short cycle’, which means it will keep switching on and off in a short space of time and use far more energy than it should. Contact a qualified engineer or installer to help you find out which size heat pump is the best option for your property.

Heat pumps don’t need a flue because they don’t burn gas to create heat like boilers do, which is the process that creates waste gases. Heat pumps work very differently from gas boilers, using naturally occurring heat energy to provide our central heating, meaning a flue is not required.

Heat pumps are located outdoors and are very effective at absorbing heat from the ground or the air, even when the weather outside is cloudy and dull. In fact, air-source heat pumps can absorb enough warmth to heat your property in temperatures as low as -20 °C.

The experts at the Energy Saving Trust say air-source heat pumps are “an energy efficient method of heating a property” as they use renewable heat from all around us. The amount of heat that they provide is greater than the amount of electricity that is used to power them.

Heat pumps do use electricity as part of the process of providing us with heating and hot water, but you can make them even more environmentally friendly by using an energy provider that offers 100% renewable power.

Heat pumps are likely to be used in many new builds going forward, with new homes built after 2025 not being able to use a gas boiler as their primary source of heat (this is due to legislation set out by the UK government to help the country reach its target of lowering CO2 emissions).

However, heat pumps can provide an energy-efficient heating option for existing properties too. Get in touch with Wright Renewables to find out whether a heat pump would be the right choice for your home.

Heat pumps do use electricity as part of the process of creating heat for hot water and heating. However, they can provide far more heat per unit of electricity than traditional appliances such as boilers, as they use heat from natural sources.

As there is no need to burn any kind of fossil fuel, no naked flame, no need for an oil storage tank or cylinders of highly flammable gas to fuel your heating then you can see that the safety argument for installing an Air Source Heat Pump is very strong indeed. According to Energy Saving Trust, air source and ground source heat pumps are the safest form of heating available.

This is one of the most common myths you’re likely to hear about air source heat pumps.

Today’s heat pumps are no longer the big, bulky and noisy pieces of equipment they were when they first came onto the market. Modern heat pumps are compact, energy efficient and make about as much noise as your refrigerator.

The noise you hear is from the pump’s fan pulling air into the system – if yours is installed correctly by a certified installer, you shouldn’t be able to hear the sound indoors.

From 1 December 2011 the installation of an air source heat pump on domestic premises is considered to be permitted development, not needing an application for planning permission, provided ALL the limits and conditions listed below are met.

These permitted development rights apply to the installation, alteration or replacement of an air source heat pump on a house or block of flats, or within the curtilage (garden or grounds) of a house or block of flats, including on a building within that curtilage. A block of flats must consist wholly of flats (e.g. should not also contain commercial premises).

Limits to be met:

• Development is permitted only if the air source heat pump installation complies with the Microgeneration Certification Scheme Planning Standards (MCS 020) or equivalent standards. Read more about the scheme.
• The volume of the air source heat pump’s outdoor compressor unit (including housing) must not exceed 0.6 cubic metres.
• Only the first installation of an air source heat pump would be permitted development, and only if there is no existing wind turbine on a building or within the curtilage of that property. Additional wind turbines or air source heat pumps at the same property requires an application for planning permission.
• All parts of the air source heat pump must be at least one metre from the property boundary.
• Installations on pitched roofs are not permitted development. If installed on a flat roof all parts of the air source heat pump must be at least one metre from the external edge of that roof.
• Permitted development rights do not apply for installations within the curtilage of a Listed Building or within a site designated as a Scheduled Monument.
• On land within a Conservation Area or World Heritage Site the air source heat pump must not be installed on a wall or roof which fronts a highway or be nearer to any highway which bounds the property than any part of the building.
• On land that is not within a Conservation Area or World Heritage Site, the air source heat pump must not be installed on a wall if that wall fronts a highway and any part of that wall is above the level of the ground storey.