A heat pump draws warmth from the outside and brings it into your home. And while they require electricity, heat pumps are more efficient than other heating systems because the amount of heat they produce is typically around 3-4 times the amount of electricity they require. This makes them very cost effective in the long term, delivering significant savings on annual energy bills. And because heat pumps don’t emit any carbon dioxide, they’re a valuable option in the challenge of reversing climate change.

A heat pump works by transferring heat from one area to another. It uses electricity to move heat from a source like the air, water, or the ground to your home.

The process of transferring heat relies on the properties and behaviours of refrigerants, which are used in a 'refrigeration cycle'. Refrigerants are chemicals that can change from a gas to a liquid and back again. By changing the pressure and temperature of the refrigerant, a heat pump can either extract or release heat from the surrounding environment. In this way, the heat pump process can be reversed in hot summer weather, turning your system into a cooling air conditioner.

Your heat pump will arrive with information explaining its Coefficient of Performance (CoP). For instance, a CoP of 3.0, means that your pump produces three units of heat for every unit of electricity consumed. However, the CoP is calculated under test conditions and, in reality, it will vary across the year in your home, depending on the temperature outside and other factors.

The Seasonal Performance Factor (SPF) is another useful figure which is used to show the efficiency of the heat pump across the whole year. Your installer is required to provide you with an SPF based on the specific design for your home before they start work. The SPF calculation demonstrates how the heat pump should perform given the average temperatures at your location and other details such as the size of your house and your radiators, providing a better indication of likely running costs and energy savings.

There are obviously costs attached to installing a heat pump, although government grants are available to help with that. But over the long term, a heat pump is likely to bring you significant energy savings because the amount of electricity that it consumes is relatively small compared to the amount of heat that is generated. However, before investing, you can get a clearer picture of the level of savings that should apply to your particular home setting.

Note also that you may see an increase in your electricity bills due to energy usage by the heat pump, but this should be more than offset by savings in gas or oil that is no longer used for heating the home.

Be aware that your home must be well insulated in order to get the best from a heat pump. Using a heat pump in an unsuitable home can significantly raise your energy bills as the device will need to work hard to heat the building.

The cost varies widely according to the size of your property and the extent of the work required. However, as a rough rule of thumb, expect to pay somewhere in the region of €12,000 to €18,000 to purchase and install a heat pump in an average-sized Irish home.

Remember, generous grants are available through the SEAI, ranging up to €6,500 per property – see here for more details.