Glossary Heating Air Conditioning

Here we gather a series of definitions or vocabulary related to the field of heating, air conditioning and renewable energy in general.

You will find all the vocabulary of heat pumps, but also solar panels. This collection is in constant evolution.


Boiler PAC

A PAC boiler is a domestic hot water tank on top of which is grafted a mini heat pump whose role is to take the calories from the air in the technical room and distribute them to the domestic hot water. The advantage compared to a traditional electric boiler is that it consumes 2 to 3 times less electricity for the same amount of heat brought to the water.ECS



This is the acronym for "Coefficient of Performance". It indicates the ratio between the heating energy produced by a heat pump and the electrical energy required to run the same heat pump. For example: if I spend 1kW to power my heat pump and it provides me with a total of 4kW of heating power for my hot water system, then the COP is 4. The higher the COP, the more free energy is drawn from the free source (air, water) and the more economical and ecological the system is. Be careful, the COP is measured at a given outside air temperature, and for a given hot water outlet temperature. Example: COP of 3.5 at -7°C (air) / 35°C (water). For any other couple of temperatures the COP is different.


CEBS stands for Certificat énergétique cantonal des bâtiments and is used to evaluate and advise on the renovation or new construction of buildings in Switzerland. Only certified experts can produce it. It gives 2 pieces of information:

  • Energy efficiency of the building envelope
  • The amount of energy required for a building in its standard use

A CEBS for a standard villa up to 200m2 costs between CHF 500 and CHF 800, according to the experts.



This is the acronym for theEat Chaude Sanitary. There are different ways to prepare it. Either by producing heat for the heating network (boiler, PACetc.), or by an independent producer with electric resistance or a heat pump boiler



Hydrosplit refers to the hydraulic connection between the indoor and outdoor unit of a split air-to-water heat pump. Split type heat pumps usually have a refrigerant connection between the two units. However, changes in the F-Gas regulations favor more environmentally friendly but more flammable fluids. Therefore, heat pump brands have developed a technology that allows the refrigerant to be left outside the house, in the outdoor unit. To this end, they install the condenser in the outdoor unit, and set up a hydraulic connection from this condenser to the indoor hydraulic module which then transfers the calories to the domestic water network.



This is the acronym for Pompe À Chaleur. This expression is used a lot and mostly by professionals among themselves.



The SCOP is the Seasonal Coefficient Of Performance. It is the COP on average over the year considering the average temperature of the region you are in. In Switzerland, the average temperature over the year is often 5°C. This value represents the amount of heating energy produced divided by the amount of electrical energy consumed, all according to the average annual climate.