The coil fan is an air conditioning unit. The main components are coil and fin heat exchangers, fans, sewers. If you pump cold water into a heat exchanger, the fan will send cold air.
First, we will see a 4 pipe system. Although this type of installation gives the user the most freedom, it is a more expensive arrangement.
Apart from this fan coil, there are recessed ceiling type ‘blower, centrifugal fan, cooling fan, air duct, centrifugal blower and sirocco blower’ (Also known as ‘พัดลม, พัดลมแบบแรงเหวี่ยง, พัดลมระบายความร้อน, ท่ออากาศ, พัดลมแบบแรงเหวี่ยงและพัดลมซิโรโค’ in the Thai language), etc.
In the 4 pipe fan coil, 2 separate coils are needed, one for heat and one for cooling. Two pipes are used for heating and two for cooling.
A valve, which is connected to the room thermostat, determines which circuit to use, hot or cold. When heating is needed, the valve opens the heating circuit. Hot water from the boiler passes through the coil.
The motor on the fan coil changes the blower, which blows across the coil and distributes warm air into the room. When calling cold air, the valve opens for cold water from the chiller, the coil is filled with cold water, and the blower distributes cold air.
The most common settings for the fan coil are 2 pipes. This is sometimes used only for cooling, heating, or both. There is only one coil in the 2 pipe system.
When a 2-pipe system is used for heating and cooling, the building engineer will replace the system from the chiller manually. With a 2 pipe system you can operate in only one mode, heating or cooling, not both. This may be somewhat uncomfortable during seasonal transitions where heat may be needed one day and the next cooling.
The fan coil is controlled by cycling the fan with a thermostat, or controlled by a water control valve with a thermostat. The thermostat can be changed manually from hot to cold, or automatically changed with aqua-stat installed in the pipe.