Introduction to Temperature Control System for Fan Coil Unit Room

(1) The room temperature control system for fan coil units consists of three parts: control panel, actuator, and valve body. The actuator and valve body form an electric two-way/three-way valve.
(2) Sensing the indoor temperature through the control panel of the room temperature controller and comparing it with the set temperature to control the on/off of the electric two-way valve, so as to achieve a constant room temperature.
(3) When the fan coil unit is stopped, the electric two-way valve is turned off to avoid the exchange of cold and hot water flowing through the fan coil unit, making the entire central air conditioning system more energy-efficient.
(4) The shut-off of the electric two-way valve, when applied to fan coil units with four sided air outlets, can prevent the output of condensed water and prevent the room from being flooded.
(5) The control panel corresponds to the fan coil unit, which has three levels of speed regulation: high, medium, and low. It can also achieve automatic speed regulation through temperature difference setting.
(6) The electric two-way valve is installed on the return water of the fan coil unit, and a filter needs to be installed in front of the valve body to ensure the safe use of the electric two-way valve.
(7) The installation height of the control panel is about 1.5 meters above the ground, and it can also be placed side by side with other lighting switches to avoid being close to heat sources or solar radiation.

Fan coil temperature control (control schematic)

-Indoor installation of fan coil temperature controller
-The thermostat is equipped with a temperature setting button to adjust the indoor temperature setting value; Equipped with a fan three speed switch; Equipped with a cooling/heating mode switch.
-Install an electric two-way valve on the return pipe of the fan coil to control the amount of water passing through the coil.
-Adjust the indoor temperature setting value through the temperature knob. The thermostat detects the actual indoor temperature in real time and automatically controls the opening/closing of the electric two-way valve to keep the room temperature constant at the set temperature value.
-When the indoor temperature reaches the set value, the electric two-way valve closes (you can choose whether the fan is turned off at the same time); Otherwise, the electric two-way valve remains open.

Common actuators and small valves for temperature control at the end of fan coil units

(1) Commonly used actuators (SUA21, SFA21/SFA71)

The electric actuator controlled by the regional valve switch is used in conjunction with the VVI/VXI series valves to achieve low-temperature hot and cold water control in HVAC systems.

Technical Specifications:

(2) Commonly used valve bodies (VVI46 and VXI46 series)

Two way or three-way valve, with internal thread connection, used for controlling regional or end devices.

Technical Specifications

(3) Common configurations:

Basic type: Control panel RAB11.1+two-way valve VVI46/three-way valve VXI46+actuator SUA21

Comfort type: control panel RDF310.2+two-way valve VVI46/three-way valve VXI46+actuator SUA21

Luxury model: control panel RDF300.02+two-way valve VVI46/three-way valve VXI46+actuator SUA21