A Heat Pump Explained

Definition of a heat pump

A heat pump is a thermodynamic device that extracts the heat found in an environment (for example air, water or earth) to transfer it to another (for example, to a house in order to heat it). The refrigerator is the most well known heat pump. A reversible heat pump will produce cool air in summer and warm air in winter.

There are 3 main types of heat pumps:

  • Air/air heat pump: heat is extracted from the air and directly transferred into a room’s air to heat or cool it.
  • Air/water heat pump: heat is extracted from the air and transferred to a water circuit, which will in turn provide heated and/or cooled flooring and/or ceiling, fan convector or air heaters.
  • Water/water heat pump: the system extracts heat from a water circuit through a  component that will transfer the heat (earth, groundwater) to another water circuit

The exhaust air heat pump concept

Inside a DATEC thermodynamic unit, the first air flow (Extraction -> Outdoor release) goes through an exchange battery “Evaporator”. The air flow frees the heat contained in the air to transfer it to the thermodynamic cycle’s heat transfer fluid. The air flow of a temperature of about 20°C when extracted is released outside at about 2°C once the heat has been removed.

At the same time, the second air flow (Outside new air->Blown in the home) goes through a second exchange battery “Condenser”. The air flow recovers the heat from the thermodynamic cycle’s heat transfer fluid. The increase in temperature between the new air, taken from outside the dwelling, and the blown air in the dwelling is approximately 35°C. This means that if the outside air temperature is 0°C, the blown air in the home would be 35°C.

  • The two flows are completely separate and there is no mixing of the two airflows, therefore ensuring fresh air renewal within the home.
  • Unlike a static dual flow system (with a static exchanger), using a heat pump with a thermodynamic cycle enables the heating of incoming air to a higher temperature than the exhaust air (20°C) of the home. Depending on the level of home heat loss, this in turn provides either some or all of the home’s heating needs.

The difference between MyDATEC and other heat pumps

Unlike other systems, MyDATEC uses the dwelling’s existing exhaust air to ventilate.  It is a source of renewable energy. If we did not reuse it, it would be lost. More importantly, it is a naturally warm source (about 20°C all year round) and rich in humidity – everything a heat pump loves and what makes the performance of MyDATEC so impressive!  In return, the need for the source that uses MyDATEC, the CMV’s exhaust air, is limited: heat recovery from exhaust air is no longer required if there is no need to ventilate! This is why the power supplied by MyDATEC is limited (up to 3kW for the heat pump), whereas an air/air heat pump could provide limitless energy.

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