Enthalpihjul

Enthalpihjul, a term of Swedish origin, translates to "enthalpy wheel" in English. It is a type of heat exchanger used in ventilation systems, particularly in energy recovery ventilators (ERVs). The primary function of an enthalpihjul is to transfer both sensible heat and latent heat from the exhaust air stream to the incoming fresh air stream. This process pre-conditions the incoming air, reducing the load on the heating and cooling systems of a building and thereby saving energy.

The enthalpihjul typically consists of a rotating rotor made of a material that can absorb and release moisture, such as aluminum coated with a desiccant. As the exhaust air passes through one side of the rotating wheel, it transfers its heat and moisture to the rotor material. The wheel then rotates, bringing the heat- and moisture-laden material into the path of the incoming fresh air. The fresh air absorbs the heat and moisture from the rotor, effectively pre-heating and humidifying it (in winter) or pre-cooling and dehumidifying it (in summer). The efficiency of an enthalpihjul is measured by its sensible and latent heat transfer capabilities. Modern enthalpihjuls can achieve high efficiencies, contributing significantly to the overall energy performance of buildings. They are a key component in achieving sustainable building designs and reducing operational costs.