Fan coil units are convectors fitted with a fan and one or more heating and/air cooling coils, with at least one fed with hot and/or chilled water. They are made up of:
- A diffusion grill
- One or more coils
- A condensate tray under the cooling coil
- One or more centrifugal fans
- A coarse filter
Fan coil units have thermal outputs of approx. 1 to 10
[kW]. They are used for conditioning buildings with several non-homogeneous
occupation zones: offices, hotels, etc.
For systems with direct control (air conditioners) they have the advantage of centralising the refrigeration production (and possibly heating) but require at least a chilled water supply system.
In addition, the fan has several speeds which can be
pre-controlled or that the user can change himself.
Fan coil units can be
installed horizontally or vertically.
They exist in uncased versions for flush fitting and encased versions for surface mounting.
Some versions known as «ducted» can be connected to a ducted network.
With false (suspended) ceilings, the fan coil units integrate between the above floor and the suspended ceiling (minimum required height 30 [cm] (1 ft)).
We can distinguish:
« 2 pipe/2 wire» fan coil units:
« 2 pipe/2 wire» fan coil units
They have a cooling coil fed with chilled water and an electric heating coil.In mid-season, they can simultaneously handle heating and cooling of a building, where the rooms are orientated differently; for example rooms with a northern façade requiring heating and southern facing rooms requiring cooling.
« 2 pipe » fan coil units:
2 pipe fan-coil units
They only have one coil fed with either hot water or cold water
subject to the season.
The coil, generally sized for cooling needs, is overpowered in winter.
These systems are not generally designed for simultaneous heating and cooling of differently orientated rooms.
« 4 pipe » fan coil units:
4 pipe FCU
They are fitted with a coil fed with chilled water and
a coil fed with hot water.
In mid-season, they permit the simultaneous heating and cooling of differently orientated rooms.