Air conditioning system: Constitution of air handling units

Air handling units (AHU) are used to control temperature and humidity sometimes the quality of the supply air.
Plants are composed of prefabricated elements assembled in a blow box and optionally in a recovery box.

Air handling units are mainly used :

To treat fresh air ventilation to introduce in buildings.

We then speak of central ventilation or central "everything looks new."

In most cases, a ventilation plant is not involved in space heating. It ensures that the heating (and possibly the cooling) the fresh air, to bring the outside temperature to room temperature. Fresh air is then blown neutral from a thermal point of view (it brings neither heat or cooling) the premises concerned.

The heating and space cooling is then performed by another system able to handle losses (excluding air) and possibly air conditioning loads. It can be for example a circuit radiators or fan coil units.

For ventilation and heating (and possibly the cooling) of premises.

The only flow required for ventilation of premises (20-30 [m3 / h] and person) is generally too low to allow heating (and possibly air conditioning) premises. In addition to the fresh air, the plant recycles while the return air in the treated premises. The plant is no longer "all fresh air."

An air handling unit may comprise: