How to choose your heat pump
This image of a refrigerator is often used to describe a heat pump. Indeed, it works according to the same principle, except that it produces heat. How does it work? By extracting calories present in ambient air, ground or water. Via a heat exchanger, the calories heat up the refrigerant gas that, by compression, transforms into fluid. It then transfers its accumulated heat to water in the tank. Remember: with 1 kWh of electricity, a heat pump produces 3 to 5 kWh free of charge. The greater the COP (Coefficient Of Performance) is, the more efficient the heat pump will be. It is one of the most important criteria to remember in choosing a heat pump. Our advice: focus on the average annual COP, it is a good indicator which takes into account the annual weather conditions.
Selecting a heat pump is a complex process. Remember that it is important to seek professional help. The numerous models have very specific configurations. For example, the choice is not likely to be the same whether it is a new and well isolated construction or a boiler replacement in an existing home. The question of the needs also arises: heating, domestic hot water production, cooling in summer time. Other parameters to consider: the type of heating appliances you have (radiators, underfloor heating systems, fan convector heating units). These are several important parameters to achieve an accurate sizing of the installation. Good to know: if you have an oversized installation, it will cause additional purchase costs, increase the number cycles (hence electricity consumption) and wear and tear. At the contrary, if undersized, your installation will be unable to meet all your needs and the back-up system will be needed too often.
At home, the most commonly used systems are aerothermal heat pumps with calories captured in the air. If the installation has been carried correctly, the return on investment is fast. It ranges from 3 to 8 years depending on the circumstances. Geothermal heat pumps (calories captured in the ground) or hydrothermal ones (calories captured in the water), because of a significant cost, administrative and implementation complexities, are rather reserved to new constructions.
The operating principle is rather simple: one or several outdoor units capture the calories from the outside cold air. The calories are extracted from this air and warm the heat transfer fluid. Once heated, it will heat the water from the system that supplies low temperature appliances (radiators or underfloor heating systems). High temperature models, in addition to the domestic hot water production, provide heating for an existing network of high temperature heaters. These models replace, without the need for taking over, the current boiler.