However, the quantity of heat delivered into your home is much greater than the quantity of electricity used to power the system, and this is what helps to make it a viable and green option to power the home. As a heat pump captures heat that is already present in the environment, the system itself does not burn any fuel and therefore emits no carbon dioxide which is why its seen as a sustainable way to heat the home. Heat pumps can be around three to four times more efficient than a traditional gas or oil boiler.
Thermal energy, or heat, is all around us and it naturally flows from a warmer place to a colder place. To provide the heat energy in a home when outdoor temperatures are colder, heat needs to flow in the other direction – from a colder place to a warmer place. The relationship between pressure and temperature is the key to how a heat pump works and it requires a gas or ‘refrigerant’ to act as the phase change material. The heat pump uses electricity to compress this refrigerant, increasing the pressure and therefore the temperature.
As the refrigerant’s heat is transferred to your home through the heat exchanger, it cools down a little. The refrigerant is then allowed to expand so that it cools even further. It’s now cold enough to absorb more heat from outside and begin the process again. The heat delivered to the heat exchanger can then be used to heat your home. This would normally be done using a central heating system – but it could also be done using warm air in a heat pump.
The key with any heating system is to reduce the time and rate at which it must work to heat the home, therefore, heating systems will only ever be as energy efficient as the quantity and quality of insulation present in the home. As the heat pump runs on electricity, it can become very inefficient if the home is poorly insulated because it will have to work harder and longer to maintain a constant temperature.
Provided the property has double-glazing windows and adequate levels of insulation in the loft, walls and floor, heat pumps can be a very efficient heating strategy for the long-term. It is thought that heat pumps in well insulated homes can be three to four times more efficient than traditional fossil fuel boilers. The efficiency levels of a heat pump can increase significantly when powered using Solar PV and Battery Storage.