Abstract: A heat pump type heating and air conditioning system includes a gas furnace or other auxiliary heat source and a thermostat and controller associated with the heat pump and the auxiliary heat source for automatically energizing the heat pump if the auxiliary heat source is inoperative regardless of whether or not the automatic heating mode has been selected or the auxiliary heating mode has been selected by the user of the system. A method of operating a heat pump system with an auxiliary heating source to automatically change from operation of the heat pump to the auxiliary heating source depending on conditions such as outdoor temperature, and to automatically change back to operation of the heat pump if the auxiliary heating source is inoperable.

Abstract: An intense field dielectric air filtration system associated with an air conditioning unit includes a microprocessor based control system which may be connected to the thermostat of the air conditioning unit to energize the air filtration system in response to a call for heat or cooling signal at the thermostat or startup of the fan motor for the air conditioning unit. The control system includes a power supply for the air filtration system together with voltage and current monitoring circuits for detecting a fault condition. Filtration system on/off and timing function reset switches are connected to the microprocessor and visual displays, including a multicolored LED bargraph display, are controlled by the microprocessor to indicate voltage potential applied to the air filtration system, a fault condition or a test mode.

Abstract: An air conditioning system may comprise an air handler, heat pump or fossil fuel furnace and may include a variable speed blower for conducting air through the system and operably connected to a controller which is also connected to a thermostat and/or humidity sensor. A discharge air temperature sensor may be disposed downstream of or embedded in a heat exchanger of the air conditioning system and connected to the controller for controlling the blower speed and airflow through the system. The amount of heating or cooling effect produced by the heat exchanger or blower speed may be adjusted to provide a constant discharge temperature or lower the humidity of air returning to a controlled space.

Abstract: A power distribution system for an air handler is reconfigureable by way of selectively connectable plug-in connectors. The air handler includes a blower associated with a first plug-in connector that is selectively connectable to a second plug-in connector of a heater and a third plug-in connector of an electric air cleaner. If the air handler includes a heater but not the electric air cleaner, then the blower connector plugs into the heater connector. If the air handler includes an electric air cleaner but not a heater, then the blower plugs into the connector of the air cleaner. And if the air handler includes both a heater and an electric air cleaner, then a three-way electrical connector couples the blower to both the heater and the air cleaner.

Abstract: A method of controlling a variable speed draft inducer motor and fan in a gas furnace. The method comprises the steps of: detecting a first fault driving the motor to a maximum operating range; detecting a second fault forcing the motor to operate towards a minimum operating range; and generating a fault signal if both faults are detected substantially simultaneously.

Abstract: A method of controlling a variable speed draft inducer motor and fan in a gas furnace. The method comprises the steps of: detecting a first fault driving the motor to a maximum operating range; detecting a second fault forcing the motor to operate towards a minimum operating range; and generating a fault signal if both faults are detected substantially simultaneously.

Abstract: An air-handler includes an AC induction motor that drives a blower to move air across a heat exchanger. A switch system selectively determines whether the blower motor operates at its rated full speed or at a reduced speed. For full speed operation, the switch system couples an AC supply at a nominal line frequency directly to the blower motor and bypasses an inverter. For reduced speed operation, the switch system couples a lower frequency output of the inverter to the blower motor. The blower is operated at a reduced speed during a pre-run dehumidification mode, a post-run heat recovery mode, and/or an electronic air-cleaning mode. The switch system allows the rated current capacity of the inverter to be substantially less that the rated full load current of the blower motor.

Abstract: A method of controlling a variable speed draft inducer motor and fan in a gas furnace. The method comprises the steps of: detecting a first fault driving the motor to a maximum operating range; detecting a second fault forcing the motor to operate towards a minimum operating range; and generating a fault signal if both faults are detected substantially simultaneously.

Abstract: An apparatus for generating a spark, particularly for igniting the gas in a gas appliance. The apparatus includes a spark generator adjacent to a combustible gas burner. The spark generator consists of at least two spark electrodes connected to a high voltage transformer. The transformer and electrodes, preferably sealed or supported in an epoxy or ceramic shell, form one easily replaceable unit. A remote circuit is operatively associated with the high voltage transformer for igniting a spark. The transformer and electrodes are located at a distance from the spark initiating circuitry and other circuitry, which in combination with the epoxy or ceramic shell provides enhanced EMI protection for sensitive remote circuitry. The ignition system may also includes a flame sensing mechanism which detects when the burner is lit.

Abstract: An apparatus and method for using a programmable variable speed motor to indicate a clogged filter while providing a constant airflow acrcss a wide range of restrictions. A motor has speed and airflow parameters and a built-in constant airflow regulator. A blower unit is connected to the motor to draw air from the inlet to the outlet. A filter reduces airborne particles as air is forced from the inlet to the outlet by operation of the motor and blower. A control system adjusts the airflow parameter of the motor based on the motor speed and environmental conditions such as light and motion. If an electronic air cleaner filter is employed, a discharge counter counts the frequency of pops occurring across the electrodes of that filter. The control system adjusts the voltage across those electrodes based on the discharge counter values.

Abstract: An HVAC controller including a first input; a second input; first means, responsive to a first signal received on the first input, for generating a first mode of operation; second means, responsive to a second signal received on the second input, for generating a second mode of operation; and third means, responsive to a third signal received substantially simultaneously on the first and second inputs, for generating a third mode of operation.

Abstract: A variable capacity refrigeration system includes a control scheme having three interrelated closed loops. The system includes a refrigeration system controller and at least one variable speed, electronically commutated DC motor driving a compressor. In the first closed loop, the controller supplies a speed command signal to a motor drive which governs the speed of the motor driven compressor. The speed of the compressor varies the system's capacity to condition the temperature of a comfort zone. A temperature sensor in the zone provides a temperature feedback signal to the controller to complete the first closed loop. In the second closed loop, the speed command signal from the controller is varied in response to a speed feedback signal received from a compressor drive which includes both the motor and the motor drive. The third closed loop is between the motor drive and the motor.

Abstract: A method of controlling a refrigeration compressor involves momentarily energizing the compressor after extended off periods. When the temperature of a comfort zone remains below its set point temperature for an extended period, such as at night, periodically energizing the compressor for brief periods improves the confort level of the zone.

Abstract: A residential heat pump installation includes a variable speed reciprocating compressor. The compressor speed control components, which include an inverter, are cooled by diverting the refrigerant liquid line into the closed controls compartment of the outdoor cabinet section and by passing the liquid line through a block of material therein upon which the compressor speed control components are mounted. The heat generated by the speed control components is transferred through the block of material and ultimately into the liquid refrigerant which is pumped through the liquid line by the operation of the compressor. Heat generated in the controls compartment is therefore removed from the compartment by system refrigerant in an manner which does not, to any significant degree, adversely affect the overall operation and efficiency of the system.

Abstract: A dual mode controller used to allow only one of either a primary heating/cooling system or a hot water heater to operate at one time. It is particularly useful where utility billing is based on peak demand. A two-position switch is used to select the mode such that in one switch position the heating/cooling system is given priority regardless of the operating status of the hot water heater, and in the other position the operating load is given priority. This relatively simple circuit includes one conventional relay and either another conventional relay or a pilot duty relay energized by an integral "doughnut" type current transformer.

Abstract: A microcomputer based defrost control for a heat pump system that "learns" from previous defrost cycles to achieve optimum defrost control at each of a plurality of outdoor temperature ranges, even if the heat pump system operating parameters change due to system aging. At the conclusion of each defrost cycle, the control determines the differential temperature between the outdoor ambient air and the outdoor heat exchanger and compares that value to a value stored in microcomputer memory representing a previous best such post-defrost differential temperature for the same ambient air temperature range. The control then calculates a defrost differential temperature initiate value, corrected to compensate for any loss of defrost performance indicated by the current post-defrost cycle differential temperature.

Abstract: An outside coil unit for a heat pump is provided which includes a refrigerant coil 16 with a protective grille 26, 28, the vertical edges of the grille being held by posts 30 and 45 which are tilted outwardly at the bottom to accordingly tilt the grille outwardly at the bottom so that ice and frost buildup onthe coil is not impeded in falling off the coil during defrost cycles.