Fan coil unit
FCUs are commonly used in HVAC systems of residential, commercial, and industrial buildings that use ducted split air conditioning or central plant cooling.
FCUs come in various configurations, including horizontal (ceiling-mounted) and vertical (floor-mounted), and can be used in a wide range of applications, from small residential units to large commercial and industrial buildings.
Noise output from FCUs, like any other form of air conditioning, depends on the design of the unit and the building materials surrounding it.
A concealed fan coil unit will typically be installed within an accessible ceiling void or services zone.
Depending upon the selected chilled water temperatures and the relative humidity of the space, it's likely that the cooling coil will dehumidify the entering air stream, and as a by product of this process, it will at times produce a condensate which will need to be carried to drain.
The simplest means to drain the condensate from multiple fan coil units will be by a network of pipework laid to falls to a suitable point.
This adjustment is typically performed during the commissioning stage of building construction and remains fixed for the lifespan of the unit.
Alternatively, certain manufacturers employ custom-wound Permanent Split Capacitor (PSC) motors with speed taps in the windings.
To enable local control, a simple speed selector switch (Off-High-Medium-Low) is provided for the occupants of the room.
The reason that these DC Fan Coil Units are, despite their apparent relative complexity, becoming more popular is their improved energy efficiency levels compared to their AC motor-driven counterparts of only a few years ago.
A straight swap, AC to DC, will reduce electrical consumption by 50% but applying Demand and Occupancy dependent fan speed control can take the savings to as much as 80%.
Fan coil units are an excellent delivery mechanism for hydronic chiller boiler systems in large residential and light commercial applications.
In these applications the fan coil units are mounted in bathroom ceilings and can be used to provide unlimited comfort zones - with the ability to turn off unused areas of the structure to save energy.
In high-rise residential construction, typically each fan coil unit requires a rectangular through-penetration in the concrete slab on top of which it sits.
