Abstract: A two temperature electronic expansion valve control for variable speed compressors that utilizes a correlation between airflow percentage and heat exchanger pressure drop to control the operation of an expansion valve. An indoor airflow percentage request may be communicated from an outdoor controller to an air handler controller. Using a correlation between airflow percentage and pressure drop across the heat exchanger, the airflow percentage may be used in predicting an outlet pressure of refrigerant exhausted from the heat exchanger. The predicted pressure drop may be used in determining a saturated temperature for the exhausted refrigerant. The determined saturated temperature may be compared to a sensed temperature of the refrigerant at the outlet of the heat exchanger to determine a superheat value, which is compared to a reference superheat value in determining the degree to open or close the expansion valve.

Abstract: Systems and methods are disclosed herein that include controlling operation of a heating, ventilation, and/or air conditioning (HVAC) system that utilizes information from a plurality of temperature sensors to monitor, verify, determine, and/or discover whether a temperature sensor is properly located in proximity to a dome of a compressor of the HVAC system. When the HVAC system determines that the temperature sensor associated with the dome of the compressor is not properly located, the HVAC system may initiate a shutdown of the compressor and/or other components of the HVAC system, generate a signal, present a message, and/or otherwise provide a notification of the improper temperature sensor placement, and/or reduce a runtime of the compressor, operate the compressor at a lower speed, reduce a power consumption of the compressor, and/or otherwise control the compressor and/or associated components to effectuate a reduced compressor dome temperature.

Abstract: An apparatus and method for controlling the heating of an airflow. According to certain embodiments, the temperature of an outdoor heat exchanger and the speed of a compressor are used to determine a blower speed for a variable speed indoor air blower. The selected blower speed may facilitate a flow of air across a second, indoor heat exchanger at an indoor volumetric flow rate that heats the airflow to a leaving air temperature. The leaving air temperature may at least seek to attain the temperature of a variable target leaving air temperature that is adjusted based on changes in outdoor ambient temperatures. Additionally, according to certain embodiments, the blower speed may be based on an indoor volumetric airflow rate that is determined, at least in part, on a determined system heating capacity and a temperature at the outdoor heat exchanger.

Abstract: Systems and methods are disclosed herein that include controlling operation of a heating, ventilation, and/or air conditioning (HVAC) system that utilizes information from a plurality of temperature sensors to monitor, verify, determine, and/or discover whether a temperature sensor is properly located in proximity to a dome of a compressor of the HVAC system. When the HVAC system determines that the temperature sensor associated with the dome of the compressor is not properly located, the HVAC system may initiate a shutdown of the compressor and/or other components of the HVAC system, generate a signal, present a message, and/or otherwise provide a notification of the improper temperature sensor placement, and/or reduce a runtime of the compressor, operate the compressor at a lower speed, reduce a power consumption of the compressor, and/or otherwise control the compressor and/or associated components to effectuate a reduced compressor dome temperature.

Abstract: An apparatus and method for controlling the heating of an airflow. According to certain embodiments, the temperature of an outdoor heat exchanger and the speed of a compressor are used to determine a blower speed for a variable speed indoor air blower. The selected blower speed may facilitate a flow of air across a second, indoor heat exchanger at an indoor volumetric flow rate that heats the airflow to a leaving air temperature. The leaving air temperature may at least seek to attain the temperature of a variable target leaving air temperature that is adjusted based on changes in outdoor ambient temperatures. Additionally, according to certain embodiments, the blower speed may be based on an indoor volumetric airflow rate that is determined, at least in part, on a determined system heating capacity and a temperature at the outdoor heat exchanger.

Abstract: A two temperature electronic expansion valve control for variable speed compressors that utilizes a correlation between airflow percentage and heat exchanger pressure drop to control the operation of an expansion valve. An indoor airflow percentage request may be communicated from an outdoor controller to an air handler controller. Using a correlation between airflow percentage and pressure drop across the heat exchanger, the airflow percentage may be used in predicting an outlet pressure of refrigerant exhausted from the heat exchanger. The predicted pressure drop may be used in determining a saturated temperature for the exhausted refrigerant. The determined saturated temperature may be compared to a sensed temperature of the refrigerant at the outlet of the heat exchanger to determine a superheat value, which is compared to a reference superheat value in determining the degree to open or close the expansion valve.

Abstract: The sufficiency of refrigerant charge in an air conditioning system is determined by a comparison of two sensed temperatures in the system, one being the liquid line temperature and the other being either the outdoor temperature or the condenser coil temperature. In one embodiment the two sensed temperatures are displayed on respective thermochromic strips which are so calibrated and juxtaposed as to provide a visual indication, by the relative positions of the two displayed sensed temperatures, as to whether the refrigerant charge is adequate. In another embodiment, the sensed liquid line temperature is displayed by way of a plurality of LEDs and the other temperature is displayed by way of a marker on a temperature scale. If the two displayed temperatures are aligned, then the refrigerant charge is optimized, and if they are not aligned, the system is undercharged or overcharged.

Abstract: A heat pump system includes an outdoor unit, an indoor unit, a compressor, and outdoor and indoor fans. An outdoor heat exchanger coil is connected to an indoor heat exchanger coil by liquid and vapor tubes. A control system limits the pressure in the vapor tubes during heating mode periods of heat pump operation by using a temperature sensor including a switch operatively connected in the indoor heat exchanger coil for sensing a temperature in the indoor heat exchanger coil. The switch operatively connects in series with a motor of the outdoor fan, such that when the temperature sensor senses a predetermined temperature in the indoor heat exchanger coil, it causes the switch to reduce a speed of the outdoor fan, thereby reducing the temperature in the vapor tubes and indoor heat exchanger coil.