Abstract: A blower unit controller and an HVAC system are disclosed herein. In one embodiment, the blower unit controller includes: (1) an input configured to receive motor operating parameters, (2) an output configured to provide a motor speed control signal to an inverter, (3) a memory configured to store a mathematical model of airflow produced by a blower motor, the mathematical model being configured to relate a motor speed to the motor operating parameters and (4) a processor configured to produce the speed control signal based on the mathematical model.

Abstract: A blower system includes a blower motor and an inverter in electrical communication therewith. The blower motor is mechanically coupled to a blower configured to generate an airstream having an airflow rate. The inverter is configured to provide a motor drive signal to the motor. A flow rate calculator is configured to determine a calculated airflow rate from motor operating parameters of the blower motor using a mathematical model of the airflow rate.

Abstract: An inverter controller, a method of operating a controller and a field-installable kit. In one embodiment, the controller includes: (1) a thermostat interface configured to receive conventional thermostat signals providing for a ventilation mode, first- and second-stage cooling modes and at least one heating mode and provide relay control signals for an inverter forward start relay, first- and second-stage cooling speed select relays and at least one heating relay and (2) an inverter controller coupled to the thermostat interface and configured to receive the relay control signals and provide an inverter forward start signal, an inverter high speed set, an inverter medium speed set and an inverter ventilation speed set.

Abstract: A blower system includes a blower motor and an inverter in electrical communication therewith. The blower motor is mechanically coupled to a blower configured to generate an airstream having an airflow rate. The inverter is configured to provide a motor drive signal to the motor. A flow rate calculator is configured to determine a calculated airflow rate from motor operating parameters of the blower motor using a mathematical model of the airflow rate.

Abstract: An air moving unit, an HVAC system and an enclosed plug fan unit are disclosed. In one embodiment, the air moving unit includes: (1) a plug fan with a blower wheel and (2) a circulation enclosure. The circulation enclosure includes: (2A) a back side and (2B) a front side having an inlet orifice corresponding to an intake area of the plug fan, the front side coupled to top, left and right sides that extend therefrom to the back side to form the circulation enclosure, wherein the blower wheel is located within the circulation enclosure and the plug fan is mechanically coupled to at least one side thereof.

Abstract: A synchronous air blower, a HVAC system and a HVAC rooftop unit is disclosed. In one embodiment, the synchronous air blower includes: (1) a permanent magnet motor having a motor shaft with a first cogged sprocket attached thereto, (3) a fan having a fan shaft with a second cogged sprocket attached thereto and (4) a synchronous belt coupled to the motor shaft and the fan shaft via the first and second cogged sprockets, the synchronous belt having teeth configured to mate with the first cogged sprocket and the second cogged sprocket.