Systems and methods for reheat control of an HVAC system
AssigneeTyco Fire & Security GmbH
InventorsJohn T. Knight, Stephen B. Pickle, Norman J. Blanton, Kerry L. Shumway
Life of this patent
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Abstract
A heating, ventilation, and/or air conditioning (HVAC) unit includes a first sensor disposed adjacent to an inlet of an evaporator configured to receive an airflow. The HVAC unit includes a second sensor disposed adjacent to an outlet of a reheat coil positioned downstream of the evaporator and configured to expel the airflow. The HVAC unit also includes a controller configured to regulate operation of a modulating reheat valve to adjust flow of a working fluid in thermal communication with the airflow to control a difference between a measurement of the first sensor and a measurement of the second sensor.
Claims20
A controller for a heating, ventilation, and air conditioning (HVAC) system, wherein the controller is configured to:
- receive a call to operate the HVAC system in a dehumidification mode;
- receive first feedback indicative of a first temperature of return air received by the HVAC system;
- receive second feedback indicative of a second temperature of supply air discharged by the HVAC system;
- determine a temperature differential between the first temperature and the second temperature;
- and
- control operation of a modulating valve to control a flow rate of a working fluid to a reheat coil in fluid communication with the return air to maintain the temperature differential at or below a non-zero threshold amount, to reduce the temperature differential below the non-zero threshold amount, or both.
A heating, ventilation, and/or air conditioning (HVAC) system, comprising:
- an enclosure defining an air flow path, wherein the enclosure is configured to receive a return air flow from a thermal load and to discharge a supply air flow toward the thermal load;
- a first heat exchanger and a reheat heat exchanger disposed within the air flow path, wherein the first heat exchanger and the reheat heat exchanger are each configured to receive a working fluid of a vapor compression system;
- a modulating reheat valve configured to transition between a plurality of discrete positions, wherein the modulating reheat valve is configured to distribute the working fluid to the reheat heat exchanger and to a second heat exchanger of the HVAC system in parallel in each discrete position of the plurality of discrete positions;
- and
- a controller configured to:
- determine a temperature differential between a first temperature associated with the return air flow and a second temperature associated with the supply air flow;
- and
- control operation of the modulating reheat valve to control a flow rate of the working fluid to the reheat heat exchanger to maintain the temperature differential at or below a non-zero threshold amount, to reduce the temperature differential below the non-zero threshold amount, or both.
A heating, ventilation, and/or air conditioning (HVAC) system, comprising:
- an enclosure defining an air flow path, wherein the enclosure is configured to receive return air from a thermal load, and the enclosure is configured to discharge supply air toward the thermal load;
- a vapor compression system configured to circulate a working fluid, wherein the vapor compression system comprises a first heat exchanger, a reheat heat exchanger, a second heat exchanger, and a modulating valve, wherein the modulating valve is configured to distribute the working fluid to the reheat heat exchanger and to the second heat exchanger in parallel, the first heat exchanger and the reheat heat exchanger are disposed within the air flow path, and the second heat exchanger is disposed external to the air flow path;
- and
- a controller configured to operate the vapor compression system in a dehumidification mode, and, in the dehumidification mode, the controller is configured to:
- receive first feedback indicative of a first temperature associated with the return air;
- receive second feedback indicative of a second temperature associated with the supply air;
- determine a temperature differential between the first temperature and the second temperature;
- and
- control operation of the modulating valve to control a flow rate of the working fluid to the reheat heat exchanger to maintain the temperature differential at or below a non-zero threshold amount, to reduce the temperature differential below the non-zero threshold amount, or both.
Dependencies are inferred from the claim text.