... control room temperature by way of on/off??controlling the fan coil units(with or without motorised valves),damper or electric ... are available for heating/cooling/ventilating control of 4-pipe fan-coil units .It is widely used in the civil architecture ... check Floor Heating Thermostat, Autuator, Modulating Butterfly Valves,?Motorized Valves, Fan Coil Unit,? Differential Pressure Controller, etc.