Systems, apparatus, and methods of controlling a variable-speed fan of an environmental maintenance module that controls temperatures of a plurality of zones of a building are provided. A first critical zone of the building is identified by analyzing the first zone temperature errors, which are used to determine a final speed setting of the variable-speed fan. Systems, apparatus, and methods of calibrating an environmental maintenance module that controls a temperature of a zone of a building are also provided. A location parameter is calculated for a plurality of zone temperatures, and a scale parameter is computed that quantifies a variation of the zone temperatures relative to a location parameter. A first temperature setpoint for the zone is determined and used in controlling the temperature of the zone.