Abstract: A method is provided for controlling operation of an air conditioning unit. The method comprises supplying line voltage to activate a motor configured to operate the air conditioning unit, and monitoring a supply of control voltage in order to control operation of the air conditioning unit, the supply of control voltage being derived from line voltage. In response to detecting a control voltage below a predetermined threshold and/or by a predetermined percentage, a time delay is initiated. The method further comprises deactivating the motor if a predetermined increase in control voltage is not detected before the time delay expires.

Abstract: A ventilation system for a building in some cases includes a main HVAC blower for moving temperature-conditioned air through the building plus a smaller ventilation blower for providing fresh air. A controller regulates the ventilation blower's speed to provide a target ventilation flow rate regardless of changes in the pressure differential between the indoor and outdoor air. To ensure that the target rate is appropriate for a particular building, the target flow rate is determined based on a ventilation setting that reflects a specified number of bedrooms and a specified amount of floor space of the building.

Abstract: A ventilation system for a building in some cases includes a main HVAC blower for moving temperature-conditioned air through the building plus a smaller ventilation blower for providing fresh air. A controller regulates the ventilation blower's speed to provide a target ventilation flow rate regardless of changes in the pressure differential between the indoor and outdoor air. To ensure that the target rate is appropriate for a particular building, the target flow rate is determined based on a ventilation setting that reflects a specified number of bedrooms and a specified amount of floor space of the building.

Abstract: A ventilation system for a building in some cases includes a main HVAC blower for moving temperature-conditioned air through the building plus a smaller ventilation blower for providing fresh air. A controller regulates the ventilation blower's speed to provide a target ventilation flow rate regardless of changes in the pressure differential between the indoor and outdoor air. To ensure that the target rate is appropriate for a particular building, the target flow rate is determined based on a ventilation setting that reflects a specified number of bedrooms and a specified amount of floor space of the building.

Abstract: A ventilation system for a building in some cases includes a main HVAC blower for moving temperature-conditioned air through the building plus a smaller ventilation blower for providing fresh air. A controller regulates the ventilation blower's speed to provide a target ventilation flow rate regardless of changes in the pressure differential between the indoor and outdoor air. To ensure that the target rate is appropriate for a particular building, the target flow rate is determined based on a ventilation setting that reflects a specified number of bedrooms and a specified amount of floor space of the building.

Abstract: An air conditioning apparatus, including an electric motor driven blower for circulating air through a cabinet, also includes one or more electric heating elements and a system controller operable to control energization of the heating elements and the blower motor at predetermined operating conditions by way of suitable relay or control elements. The system includes a heating interlock relay to prevent energization of the one or more heating elements if the blower motor is inoperable, operating at other than a predetermined range of speeds or the system controller detects a malfunctioning heating element control relay or the like.

Abstract: A ventilation system for a building in some cases includes a main HVAC blower for moving temperature-conditioned air through the building plus a smaller ventilation blower for providing fresh air. A controller regulates the ventilation blower's speed to provide a target ventilation flow rate regardless of changes in the pressure differential between the indoor and outdoor air. To ensure that the target rate is appropriate for a particular building, the target flow rate is determined based on a ventilation setting that reflects a specified number of bedrooms and a specified amount of floor space of the building.

Abstract: An air conditioning control system and method for compensating for heat gain or loss in an air conditioned space due to window area and temperature differential between outdoor temperature and indoor temperature. For predetermined amounts of window area, as a percent of total wall area defining an enclosed space, the thermostat setpoint or measured temperature is adjusted as a function of the temperature differential between the enclosed space and the outdoor ambient temperature, for example. Data may be accumulated and stored in a controller memory for various types of structures and rates of heat transfer therethrough for various amounts and type of window area as a percent of the total wall area, for example.

Abstract: A method is provided for controlling operation of an air conditioning unit. The method comprises supplying line voltage to activate a motor configured to operate the air conditioning unit, and monitoring a supply of control voltage in order to control operation of the air conditioning unit, the supply of control voltage being derived from line voltage. In response to detecting a control voltage below a predetermined threshold and/or by a predetermined percentage, a time delay is initiated. The method further comprises deactivating the motor if a predetermined increase in control voltage is not detected before the time delay expires.

Abstract: HVAC apparatus is configured to include a control system with a controller which may be connected directly to a personality module for transferring information stored in the controller related to historic operating conditions of the apparatus to the module, or information may be transferred to the controller from the module to configure the controller for operation of the apparatus at selected operating conditions of temperature, pressure and blower motor speed, for example. The personality module includes a memory circuit and a connector for releasably connecting the module to the control system of the apparatus for transferring information between the module and the controller.

Abstract: A user interface for a control system for an air conditioning apparatus includes a visual display and keys for scrolling menu items and entering commands to the control system. The interface is mounted in the apparatus cabinet and on a rotatable bracket to orient the interface for ease of reading the display and actuating the respective keys.

Abstract: An air conditioning (HVAC) system for a residential dwelling or other building with enclosed spaces includes multiple thermostats hard wire interconnected or communicating via radio frequency transceivers. The thermostats each include control circuits for adjusting the setpoint temperature at any one thermostat and displaying the set temperature at all thermostats, setting the time at any one thermostat and displaying the time at all thermostats, controlling the thermostat temperature setting from a selected one of the thermostats and providing a setpoint for control of the air conditioning system based on an average temperature sensed by all of the thermostats. A method for correctly setting a thermostat time display to one of Daylight Saving Time or Standard Time and displaying an icon identifying one or the other is disclosed.

Abstract: An HVAC system includes a variable speed electric motor driven fan for circulating air to an enclosed space through an indoor unit for providing heating or cooling effect to air circulated through the indoor unit. A controller with user or system installer actuatable switches includes a programmable microcontroller providing a pulse width modulated (PWM) signal to a motor control unit to select a predetermined air flowrate less than full air flowrate during system startup and shutdown. User input parameters include selected percentages of full air flowrate to satisfy requirements for reduced noise level, lower humidity and for improved sensible heating of air being circulated, the latter being effective particularly for heat pump applications. Selection of pre-run, short run and shutdown cycles may be provided.

Abstract: An air conditioning (HVAC) system for a residential dwelling or other building with enclosed spaces includes multiple thermostats hard wire interconnected or communicating via radio frequency transceivers. The thermostats each include control circuits for adjusting the setpoint temperature at any one thermostat and displaying the set temperature at all thermostats, setting the time at any one thermostat and displaying the time at all thermostats, controlling the thermostat temperature setting from a selected one of the thermostats and providing a setpoint for control of the air conditioning system based on an average temperature sensed by all of the thermostats. A method for correctly setting a thermostat time display to one of Daylight Saving Time or Standard Time and displaying an icon identifying one or the other is disclosed.

Abstract: An air conditioning (HVAC) system for a residential dwelling or other building with enclosed spaces includes multiple thermostats hard wire interconnected or communicating via radio frequency transceivers. The thermostats each include control circuits for adjusting the setpoint temperature at any one thermostat and displaying the set temperature at all thermostats, setting the time at any one thermostat and displaying the time at all thermostats, controlling the thermostat temperature setting from a selected one of the thermostats and providing a setpoint for control of the air conditioning system based on an average temperature sensed by all of the thermostats. A method for correctly setting a thermostat time display to one of Daylight Saving Time or Standard Time and displaying an icon identifying one or the other is disclosed.

Abstract: A user interface for a control system for an air conditioning apparatus includes a visual display and keys for scrolling menu items and entering commands to the control system. The interface is mounted in the apparatus cabinet and on a rotatable bracket to orient the interface for ease of reading the display and actuating the respective keys.

Abstract: A forced airflow air conditioning system includes a humidifier which is operable to humidify air bypassed from a supply air plenum to a return air duct or vice versa, the humidifier airflow being controlled by a damper closure member which is operably connected to a bimetal spring actuator or to an electric motor, both responsive to temperature of air flowing through the system. One embodiment includes an electric motor connected to the damper closure member and in circuit with a humidistat for opening the damper when humidification is required.

Abstract: An air conditioning apparatus, including an electric motor driven blower for circulating air through a cabinet, also includes one or more electric heating elements and a system controller operable to control energization of the heating elements and the blower motor at predetermined operating conditions by way of suitable relay or control elements. The system includes a heating interlock relay to prevent energization of the one or more heating elements if the blower motor is inoperable, operating at other than a predetermined range of speeds or the system controller detects a malfunctioning heating element control relay or the like.

Abstract: HVAC apparatus is configured to include a control system with a controller which may be connected directly to a personality module for transferring information stored in the controller related to historic operating conditions of the apparatus to the module, or information may be transferred to the controller from the module to configure the controller for operation of the apparatus at selected operating conditions of temperature, pressure and blower motor speed, for example. The personality module includes a memory circuit and a connector for releasably connecting the module to the control system of the apparatus for transferring information between the module and the controller.

Abstract: An air conditioning control system and method for compensating for heat gain or loss in an air conditioned space due to window area and temperature differential between outdoor temperature and indoor temperature. For predetermined amounts of window area, as a percent of total wall area defining an enclosed space, the thermostat setpoint or measured temperature is adjusted as a function of the temperature differential between the enclosed space and the outdoor ambient temperature, for example. Data may be accumulated and stored in a controller memory for various types of structures and rates of heat transfer therethrough for various amounts and type of window area as a percent of the total wall area, for example.