A heat pump is a device that draws heat energy from the building's surroundings (air, ground, or water) and transfers it to the central heating installation. In this way, it obtains clean, ecological energy at low costs (electricity used to power the compressor). It is used for heating the building, utility water, and also for cooling rooms in hot weather. While looking for a comfortable and cheap solution for heating your home we often think about using a heat pump. Most importantly, we want the heat pump to provide lower costs of our heating and we want it to be reliable to us for many years. The reason for that is that the prices of fuels are changing rapidly. They are getting higher every year and it is difficult to predict what the situation will be in the next few years. Two-thirds of the cost of maintaining a building is related to heating. By using an inexpensive heat source, we can ensure low heating costs for up to 50 years. Currently, heat pumps are a reliable, economical, and environmentally friendly source of heat with a guaranteed future. In Switzerland, every third house is already equipped with a heat pump.