Fan coil unit

A fan coil unit (FCU) is a simple device consisting of a heating or cooling coil and fan. It is part of an HVAC system found in residential, commercial, and industrial buildings. Since it does not have any ductwork, a fan coil unit is used to control the temperature only in the space where it is installed. It is controlled either by a manual on/off switch or by thermostat.

Due to their simplicity, fan coil units are more economic to install than ducted or central heating systems. However, they can be noisy because its fan is within the same space.

Design and operation

The coil receives hot or cold water from a central plant, and removes or adds heat from the air through heat transfer. Fan coil units can contain their own internal thermostat, or can be wired to operate with a remote thermostat.

Fan coil units circulate hot or cold water through a coil in order to condition a space. The unit gets its hot or cold water from a central plant, or mechanical room containing equipment for removing heat from the central building's closed-loop. The equipment used can consist of machines used to remove heat such as a chiller or a cooling tower and equipment for adding heat to the building's water such as a boiler or a commercial water heater.

Fan coil units are divided into two types: Two (2) pipe fan coil units or Four (4) pipe fan coil units. Two pipe fan coil units have one (1) supply and one (1) return pipe. The supply pipe supplies either cold or hot water to the unit depending on the time of year. Four (4) pipe fan coil units have two (2) supply pipes and two (2) return pipes. This allows either hot or cold water to enter the unit at any given time.

Areas of use

Fan coil units are typically used in spaces where economic installations are preferred such as unoccupied storage rooms, corridors, loading docks.

In high-rise buildings, fan coils may be stacked, located one above the other from floor to floor and all interconnected by the same piping loop.

Installation

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. Usually, there are either 3 or 5 copper pipes that go through the floor. The pipes are usually insulated with refrigeration insulation, such as acrylonitrile butadiene/polyvinyl chloride (AB/PVC) flexible foam (Rubatex or Armaflex brands) on all pipes or at least the cool lines.

Unit Ventilator

A unit ventilator is an fan coil unit that is used mainly in classrooms, hotels, apartments and condominium applications. A unit ventilator can be a wall mounted or ceiling hung cabinet, and is designed to use a fan to blow air across a coil, thus conditioning the space which it is serving.

Examples of unit ventilators:
*McQuay [http://www.mcquay.com/McQuay/ProductInformation/UnitVent/UnitVentilators]
*Nesbitaire [http://www.nesbittaire.com/na_vents_903.html]
*Trane [http://www.trane.com/Commercial/Dna/View.aspx?i=1094]

ee also

* Thermal insulation
* HVAC
* Construction
* Intumescent
* Firestop

External links

* [http://www.temspec.com/guides/Vertical%20Hi-Rise%20Fan%20Coil%20Units%20-%20Models%20TVA,%20TVE,%20TVS,%20TFA,%20TFE,%20TFS,%20TCA,%20TCE,%20TCS-%202007.pdf Temspec FCUs]