YH Heating valve actuator
YC Cooling valve actuator
YHC Heating/cooling valve actuator
M1 1-speed or 3-speed fan, DC 0…10 V fan
B1 Return air temperature sensor or external room temperature
sensor (optional)
● Use case a): IAQ - CO
2
control in fan coil systems with integrated fresh air
damper
The fresh air is provided via an external ventilation system, e.g. an air handling
unit (AHU)
● Use case b): IAQ - CO
2
control in fan coil systems with direct fresh air from
outside
By activating the frost protection function and setting the frost protection
setpoint (P109), the outside fresh air is provided via damper into the fan coil
and then to the room. When the outside temperature (sent to RDG2..4KN via
e.g. LTE-mode, zone 31) drops below the frost protection setpoint, the
thermostat closes the damper to protect the equipment.
● Use case c): IAQ - CO
2
monitoring (P450 = 0 or 1) or control (P450 = 2 or 3), in
traditional fan coil systems (without built-in fresh air damper)
For CO
2
control, the fresh air is provided via an external ventilation system.
Damper controlled via RDG2..4KN is required.
● Use case d): IAQ - CO
2
monitoring (P450 = 0 or 1) or control (P450 = 2 or 3) in
universal heating and cooling systems
For CO
2
control, the fresh air is provided via an external ventilation system.
Damper controlled via RDG2..4KN is needed.
The thermostats support indoor air quality control on several HVAC fan coil or
universal applications, for different types of control outputs and fan signals.
Consult the tables below to determine whether the thermostat can control your
equipment:
● Select HVAC application (e.g. 4-pipe)
● Select fan type (DC, 3-speed or no fan (fan disabled))
● Check available control signals (On/Off, PWM, 3-pos, DC)
● Verify availability of IAQ control type (DC or On/Off damper)