Advantages and Installation Accessories of Fan Coil Units

1. Main features of fan coil unit:

a. The fan coil unit has an exquisite structure, compactness, durability, beautiful appearance, and noble elegance. ​

b. The fan coil unit is made of high-quality galvanized sheet casing, and the condensate water pan is integrally formed by molding technology. There are no welds or solder joints, and the insulation material that complies with fire protection regulations is integrally connected to the water pan. ​

c. The fan coil unit is small in size: the body design is lightweight. Drainage pipes and lines are easy to install, and the left and right connection and air return methods can be changed at any time to suit the site conditions. The unit can be installed in any space. ​

Internal structure diagram of horizontal concealed fan coil unit
Internal structure diagram of the horizontal concealed fan coil unit

d. High fan coil efficiency: The advanced tube expansion process ensures close contact between the heat exchanger copper tube and aluminum foil, and has good heat transfer performance;

e. The fan coil unit has low noise: Reasonable fan and airflow structure design, high-quality sound-absorbing and thermal insulation materials make the unit noise 1-3dB (A) lower than the national standard;

f. The fan coil unit has low energy consumption: the fan and the heat exchanger are reasonably matched, and the air volume is adjustable in three levels so that the fan consumes the most electricity.

g. The fan coil unit mainly relies on the forced effect of the fan to heat the air as it passes through the surface of the heater. This strengthens the convection heat exchanger between the radiator and the air and can quickly heat the air in the room.

h. The fan coil is the terminal device of the air conditioning system. Its working principle is to continuously recirculate the air in the room where it is located so that the air passes through the cold water (hot water) coil and is cooled (heated) to maintain a constant room temperature. Usually, it is processed by a fresh air unit and then sent indoors to meet the demand for fresh air volume in air-conditioned rooms. ​
However, since this heating method is only based on convection heat transfer, the indoor comfort level cannot be reached optimally. Therefore, it is only suitable for places where people stay for a short time, such as offices and hotels, and is not used in ordinary residences. Due to the addition of fans, the construction and operating costs are increased, and the maintenance and management of the equipment are also more complicated. ​


i. Use of fan coil unit control mostly adopts a local control scheme, which is divided into two types: simple control and temperature control.

Simple control: Use the three-speed switch to directly manually control the three-speed conversion and start and stop the fan.

Temperature control: The STC series thermostat automatically controls the opening and closing of the STV series electric two/three-way valve and the three-speed conversion of the fan based on the comparison and calculation of the set temperature and the actual detected temperature. Or directly control the three-speed conversion and start-stop of the fan, thereby achieving constant temperature by controlling the system water flow or air volume. ​

2. General technical requirements for installation:

a. Before installing the fan coil unit, visual inspection, three-speed operation and hydraulic pressure test of the unit should be carried out.

b. When connecting pipes to fan coil units, hoses should be used.

c. The water supply and return valves and filters of the fan coil should be installed close to the coil and all above the condensate pan.

d. When hoisting the fan coil, the hoisting should be firm and in the correct position, with a slope of 0.003 towards the outlet of the condensate pan. The connection between the boom and the coil should be fastened with double nuts. Concealed coil ceilings should have movable inspection doors to facilitate unit and maintenance.

e. Special tools should be used when connecting the fan coil to the water supply and return pipes to prevent the coil interface. A 200mm long plastic hose should be used at the connection between the condensate pan and the condensate pipe and clamped with a special pipe clamp.

f. The fan coil should be connected to the pipe after flushing to prevent the coil from being blocked; if a filter is installed, it should be disassembled and cleaned after the system is debugged and run before delivery.

Before installation of the fan coil unit, a single three-speed test run, and a hydraulic pressure test should be carried out. The test pressure is 1.5 times the system working pressure. If there is no leakage, it is qualified.

Working principle of vertical surface-mounted fan coil cooling and heating
Working principle of vertical surface-mounted fan coil cooling and heating


3. Fan coil installation accessories:

Soft connection
Electric two-way valve
Shut-off valve
Y type filter
Air duct soft joint
Condensate drainage

4. Precautions for fan coil installation:

The inlet and outlet valves of the fan coil unit should be installed as close as possible to the condensate pan to prevent dripping water from the valve stem from leaking into the room.

The connections between the air duct, return air box air outlet and the fan coil unit should be tight and firm.

The drainage slope should be correct, and the fan coil should be slightly sloped toward the condensate drain outlet during installation.