sisälämmönvaihtimen

Sisälämmönvaihdin is a Finnish term that translates to "indoor heat exchanger" or "domestic heat exchanger." It refers to a device used in building ventilation systems, particularly in heat recovery ventilation (HRV) or energy recovery ventilation (ERV) units. The primary function of a sisälämmönvaihdin is to transfer heat between the outgoing stale air from inside a building and the incoming fresh outdoor air.

In a typical setup, stale, warm air from the interior of the building is drawn through one side of the heat exchanger. Simultaneously, cold, fresh air from outside is drawn through the other side. The sisälämmönvaihdin, often made of a material like aluminum or plastic, has many thin plates or channels that allow for a large surface area of contact between the two air streams. As the air streams pass through, heat energy moves from the warmer air to the colder air without the air masses mixing.

This process preheats the incoming fresh air, reducing the energy demand on the building's primary heating system. In warmer months, the same principle can be applied in reverse, pre-cooling incoming fresh air with the heat from the outgoing stale air, thus reducing the load on air conditioning systems. The efficiency of a sisälämmönvaihdin is a key factor in the overall performance and energy savings of a ventilation system. Different types exist, including plate heat exchangers and rotary heat exchangers, each with its own advantages and applications.