MLM Wall Thermostat with Relative Humidity Control

The Rickard MLM+ Wall Thermostat with Relative Humidity Control (wall controller) has been designed to give the user primary temperature control and secondary RH level control to maintain comfort levels and keep RH levels in check respectively. The wall controller senses temperature and controls the temperature of the zone by modulating the damper of each VAV diffuser. When the RH value rises above an adjustable threshold value (RH% Threshold High), the diffusers open fully until the RH value is brought down to an acceptable level (RH% Threshold Low). Thereafter the diffuser returns to primary temperature control mode. The Relative Humidity of the supply air should be lower than the RH% Threshold Low value to allow for the relative humidity to be controlled adequately.

Note: RH control has priority over temperature control i.e. temperature will not be controlled when RH levels have risen above the RH% Threshold High Level. If temperature control mode is required while the diffuser is in RH flush mode, the user can override it to revert to temperature control mode. This can be activated by pressing and holding the enter button until the controller buzzes.