roottorilämmönvaihtimet

Root-and-rotor heat exchangers, known in Finnish as roottorilämmönvaihtimet, are a type of rotary heat exchanger used in applications such as heat recovery in ventilation systems. They consist of a rotor that rotates slowly within a housing. The rotor is typically made of a material with high thermal conductivity, such as aluminum or a ceramic.

As warm exhaust air passes through one half of the rotating rotor, it heats up the rotor material. Simultaneously, cooler fresh air passes through the other half of the rotor. As the rotor turns, the heated section moves into the path of the fresh air, transferring its stored heat. This continuous rotation allows for efficient transfer of thermal energy between the exhaust and supply air streams without significant mixing of the air itself.

The primary advantage of roottorilämmönvaihtimet is their high efficiency in recovering heat, often exceeding 80%. They can also transfer moisture, which can be beneficial in humid climates to pre-condition incoming air. However, a small amount of cross-contamination between the air streams is unavoidable due to the nature of the rotary design. Maintenance typically involves cleaning the rotor and checking the drive mechanism. They are widely employed in commercial buildings and industrial processes where energy efficiency is a key consideration.