Fan coil systems

In a fan coil unit, hot or chilled water flows through a coil and a fan blows air across it to heat or cool the room. A room thermostat measures the temperature and controls the unit. 2- or 3-way motorised valves are recommended for stable operation and energy savings.

Ideal for multi-room buildings and spaces where ductwork is difficult. Units can be installed under windows, above suspended ceilings, below ceilings or in the floor.

Types

2-pipe

One coil with one supply and one return pipe. Heating and cooling cannot run at the same time; a changeover is needed.

4-pipe

Separate heating and cooling coils with two supply and two return pipes. Each zone heats or cools independently.

Advantages

• Individual climate per zone, room-level thermostat control
• Long service life: equipment sits indoors, away from rain, snow and heat
• Quiet operation, ideal for hospitals, hotels and schools
• Flow control and pump energy savings with 2-way control valves
• Lower heat loss through small pipe surfaces, low risk of duct leakage
• No dedicated plant room needed; simple installation and flushing
• Adjustable fan speed

Fan coil components

Fan coils come in wall-mounted, floor-standing, ceiling-suspended and ducted versions. Chassis (uncased) models cost less and are designed for concealed installation above a suspended ceiling or inside a decorative casing.

Heat exchanger coil

A unit with one coil is a two-pipe fan coil; with two coils it is a four-pipe unit, connected to both the chiller and the heating system and able to heat like a radiator in winter.

Fan and motor

Output is controlled by changing the fan speed. When the room reaches its set point the fan stops but water keeps flowing, so a three-way valve is fitted ahead of the coil to bypass the water around the unit.

Condensate tray

Collects the condensate formed during cooling.

Air filter

Easy to remove and wash; captures dust and fine particles.

Electric heater

Some models include an electric heating element for extra heat.

Controls

Unit-mounted panel, wired controller or infrared remote.