HVAC Fresh Air Handling Unit With Heat Recovery Wheel

A Fresh Air Handling Unit With Heat Recovery Wheel (often abbreviated as FAHU with Heat Recovery Wheel) is a type of HVAC (Heating, Ventilation, and Air Conditioning) equipment designed to supply fresh outdoor air to indoor spaces while efficiently recovering sensible and latent heat (or cold) from the exhaust air being discharged from the building.
Its core feature lies in the integration of a heat recovery wheel (also called a rotary heat exchanger)—a rotating, honeycomb-structured wheel typically made of materials with high heat and moisture transfer capabilities (such as aluminum foil or desiccant-coated media). The working principle is as follows:
The wheel rotates continuously between the fresh air stream (outdoor air entering the unit) and the exhaust air stream (indoor air exiting the building).
When the wheel passes through the exhaust air side, it absorbs heat (and moisture, if using a desiccant wheel) from the warm exhaust air.
As the wheel rotates to the fresh air side, it releases the absorbed heat (and moisture) to preheat (or pre-cool and humidify/dehumidify) the incoming fresh air.
This process significantly reduces the energy required to heat, cool, or condition the fresh air to the desired indoor temperature and humidity, thereby improving the energy efficiency of the HVAC system and reducing operating costs. The unit also typically includes components such as filters (to purify fresh air), fans (to drive air flow), and sometimes coils (for additional heating or cooling) to ensure the supplied fresh air meets indoor air quality and thermal comfort requirements.