Abstract: A method of heating a component within a heating, ventilation and air conditioning (HVAC) system is provided. The method includes maintaining a non-heating condition of the HVAC system component when the HVAC system component is in a non-operational state. The method also includes determining when the HVAC system component will switch from the non-operational state to an operational state, the determination based on a threshold parameter being met. The method further includes operating a heating device from the non-heating condition to a heating condition to heat the HVAC system component from a temperature to a target temperature suitable for the operational state of the HVAC system component.

Abstract: A method of heating a component within a heating, ventilation and air conditioning (HVAC) system is provided. The method includes maintaining a non-heating condition of the HVAC system component when the HVAC system component is in a non-operational state. The method also includes determining when the HVAC system component will switch from the non-operational state to an operational state, the determination based on a threshold parameter being met. The method further includes operating a heating device from the non-heating condition to a heating condition to heat the HVAC system component from a temperature to a target temperature suitable for the operational state of the HVAC system component.

Abstract: A heating and cooling system includes a compressor having a discharge outlet and a suction inlet; a first heat exchanger; a second heat exchanger; a four-way valve including: a body including a first port connected to the discharge outlet, a second port connected to the first heat exchanger, a third port connected to the suction inlet and a fourth port connected to the second heat exchanger; a slider positioned in the body; and an actuator assembly configured to impart linear motion to the slider; and a controller configured to send a command to the actuator assembly to move the slider to one of a first position, a second position or a third position.

Abstract: A method of operating an air conditioning system including: operating a refrigerant compression device at a demand speed to circulate refrigerant through a refrigeration circuit; monitoring, using a temperature sensor, a temperature of external ambient air; monitoring, using a pressure sensor, a pressure of the refrigerant within the refrigerant circuit; detecting, using a controller, when the temperature of external ambient air is greater than a selected temperature; detecting, using the controller, when the pressure of the refrigerant is greater than a selected pressure; and reducing the speed of the refrigerant compression device to a selected speed for a first duration of time when the temperature of external ambient air is greater than the selected temperature and the pressure of the refrigerant is greater than the selected pressure.

Abstract: A system and method of controlling an oil flow within a refrigeration system, the system including a compressor, an expansion device in flow communication with the compressor, and an electronic controller in communication with the expansion device and the compressor, wherein the electronic controller is configured to operate in an oil return mode based at least in part on an operational speed and a continuous operational run time of the compressor.

Abstract: A method of operating an air conditioning system including: operating a refrigerant compression device at a demand speed to circulate refrigerant through a refrigeration circuit; monitoring, using a temperature sensor, a temperature of external ambient air; monitoring, using a pressure sensor, a pressure of the refrigerant within the refrigerant circuit; detecting, using a controller, when the temperature of external ambient air is greater than a selected temperature; detecting, using the controller, when the pressure of the refrigerant is greater than a selected pressure; and reducing the speed of the refrigerant compression device to a selected speed for a first duration of time when the temperature of external ambient air is greater than the selected temperature and the pressure of the refrigerant is greater than the selected pressure.

Abstract: A method for determining a level of refrigerant charge in a vapor compression system having a compressor, a condenser, an expansion device and an evaporator operatively connected in serial relationship in a refrigerant flow circuit having a refrigerant, includes receiving information indicative of at least one of a compressor torque or compressor current; and determining whether the refrigerant charge is within a defined tolerance or whether the refrigerant is to be added or recovered in response to the receiving of the information.

Abstract: A method and apparatus are provided for indicating the status of the refrigerant charge in an air conditioning system based upon the degree of subcooling present in the condensed refrigerant system temperature measurements. The status of the refrigerant charge in the system is indicated in real-time on a service panel for access by a field service technician. The status of the refrigerant charge in the system on a time-average basis for a specified period of operation is presented on an indicator panel. The indicator panel includes a first indicator light indicating that the refrigerant charge is low, a second indicator light indicating that the refrigerant charge is high, and a third indicator light indicating that the refrigerant charge is correct.

Abstract: A method for controlling a system includes receiving system demand data; processing the system demand data; defining a first value of a first system operating parameter; receiving system condition data; associating the first value of the first system operating parameter with a first operating map function; determining whether the system condition data exceeds a threshold of the first operating map function; determining whether the system condition data exceeds a threshold of a second operating map function responsive to determining that the system condition data exceeds the threshold of the first operating map function; and changing the first value of the first system operating parameter to a second value associated with the second operating map function responsive to determining that the system condition data does not exceed the threshold of the second operating map function.

Abstract: A method for controlling a system comprising, receiving system demand data (402), processing the system demand data (404), defining a first system operating parameter (404), receiving system condition data (406), associating the system condition data with an operating map function (406), determining whether the system condition data exceeds a threshold of the operating map function (408), and changing the first system operating parameter responsive to determining that the system condition data exceeds the threshold of the operating map function (411).

Abstract: A refrigerant vapor compression system includes a compressor, an expansion valve, a compressor speed sensor operatively connected to the compressor, an ambient temperature sensor, and a controller operatively coupled to the expansion valve, compressor speed sensor and ambient temperature sensor. The controller including a superheat control that is configured and disposed to selectively activate the expansion valve to establish a desired superheat value based on a speed of the compressor as sensed by the compressor speed sensor and ambient temperature as sensed by the ambient temperature sensor.

Abstract: A method for determining a level of refrigerant charge in a vapor compression system having a compressor, a condenser, an expansion device and an evaporator operatively connected in serial relationship in a refrigerant flow circuit having a refrigerant, includes receiving information indicative of at least one of a compressor torque or compressor current; and determining whether the refrigerant charge is within a defined tolerance or whether the refrigerant is to be added or recovered in response to the receiving of the information.

Abstract: A method for determining the adequacy of the refrigerant charge in an air conditioning system based upon both the instantaneous degree of subcooling present in the liquid refrigerant in the refrigerant line at a location whereat only liquid refrigerant is present and a calculated average subcooling value based upon accumulated instantaneous subcooling values. The adequacy of the refrigerant charge in the system may be indicated by an alert indicating “check charge” or by a series of lights including a first indicator light indicating that the refrigerant charge is low, a second indicator light indicating that the refrigerant charge is high, and a third indicator light indicating that the refrigerant charge is correct.

Abstract: A method for controlling a system comprising, receiving system demand data (402), processing the system demand data (404), defining a first system operating parameter (404), receiving system condition data (406), associating the system condition data with an operating map function (406), determining whether the system condition data exceeds a threshold of the operating map function (408), and changing the first system operating parameter responsive to determining that the system condition data exceeds the threshold of the operating map function (411).

Abstract: A method and apparatus are provided for indicating the status of the refrigerant charge in an air conditioning system based upon the degree of subcooling present in the condensed refrigerant system temperature measurements. The status of the refrigerant charge in the system is indicated in real-time on a service panel for access by a field service technician. The status of the refrigerant charge in the system on a time-average basis for a specified period of operation is presented on an indicator panel. The indicator panel includes a first indicator light indicating that the refrigerant charge is low, a second indicator light indicating that the refrigerant charge is high, and a third indicator light indicating that the refrigerant charge is correct.

Abstract: A method for determining the adequacy of the refrigerant charge in an air conditioning system based upon both the instantaneous degree of subcooling present in the liquid refrigerant in the refrigerant line at a location whereat only liquid refrigerant is present and a calculated average subcooling value based upon accumulated instantaneous subcooling values. The adequacy of the refrigerant charge in the system may be indicated by an alert indicating “check charge” or by a series of lights including a first indicator light indicating that the refrigerant charge is low, a second indicator light indicating that the refrigerant charge is high, and a third indicator light indicating that the refrigerant charge is correct.

Abstract: The refrigerant charge adequacy of an air conditioning system is determined by the sensing of two temperatures in the system, one being at a midpoint in a condenser coil and the other being the temperature in the liquid line of the condenser discharge, with the difference then being indicative of the degree of subcooling, which, in turn, may be indicative of refrigerant charge condition. The method is refined by measuring a third temperature at the compressor discharge, with the three temperature values then being used to calculate a pair of residual values which provide an indication of whether the two temperature approach is useful in determining charge adequacy under the existing conditions and if not, whether the system is overcharged or undercharged.

Abstract: A tube is provided with an indentation long enough to receive a sensor bulb and having a nominal curvature corresponding to the outer curvature of the sensor bulb whereby, when secured by a clamp, which is suitably tightened, at least one of the members will deform to the curvature of the other member thereby achieving area contact between the members.

Abstract: A tube is provided with an indentation long enough to receive a sensor bulb and having a nominal curvature corresponding to the outer curvature of the sensor bulb whereby, when secured by a clamp, which is suitably tightened, at least one of the members will deform to the curvature of the other member thereby achieving area contact between the members.

Abstract: In a heat pump system designed for use with a relatively low pressure refrigerant, provision is made, by use of a vapor pressure control system, to use a higher pressure refrigerant without replacement of the indoor coil and the line set. The vapor pressure is sensed during periods of heat pump operation, and when the pressure reaches a predetermined maximum threshold level, the outdoor fan speed is reduced to thereby cause the vapor pressure to be reduced. When the vapor pressure is reduced to a predetermined minimum threshold level, then the fan speed is resumed so as thereby allow the vapor pressure to again be increased.