Abstract: Plenum fan banding that effectively changes the width of the fan blades in a plenum fan for a HVAC unit. A removable and replaceable band attaches to the back of a fan wheel of the plenum fan so that the band is located within the circle of the fan blades and extends outward perpendicular to the back of the wheel. The band is provided with tabs that insert through slots provided in the back of the fan wheel, and the tabs can be bent over as a means of removably securing the band to the fan wheel. The band effective reduces the functional width of the fan blades in proportion to the width of the band.

Abstract: A control system for a HVAC unit for controlling the humidity and temperature of interior building space at desired levels regardless of the outside temperature and humidity conditions. This system is more efficiently so that it operates with less energy consumption than current HVAC systems. The control system employs a combination of modulated return air bypass, modulated capacity compressor, and modulating hot gas reheat to maintain proper interior space humidity, and temperature while maintaining adequate ventilation within the interior building space. The system employs feed forward control to prevent overheating the interior building space with reheat and also, once humidity requirements are met, resets low pressure limit settings at the exit of the evaporator to minimize use of reheat in the operation of the unit.

Abstract: A method and device for concurrently transferring sensible heat from the warmer of either an incoming outside airstream or an outgoing exhaust airstream to the other stream and transferring latent heat from the wetter of either the incoming outside airstream or the outgoing exhaust airstream to the other stream prior to the incoming airstream entering a standard heating and air conditioning unit. The method and apparatus both employ a rotating heat wheel impregnated with a dry desiccant such as silica gel in order to accomplish the simultaneous transfer of both sensible and latent heat between the two airstreams.