Systems for refrigerant leak detection and management

Abstract

A control system for a heating, ventilation, and/or air conditioning (HVAC) system includes a sensor configured to detect a concentration of refrigerant in air. The control system also includes a controller configured to receive feedback from the sensor indicative of the concentration of refrigerant in air, determine that the concentration of refrigerant in air is less than a threshold value, and determine that the HVAC system is in an operating mode. The controller is configured to operate a blower of the HVAC system for a predetermined time period based on the determinations that the concentration of refrigerant in air is less than the threshold value and that the HVAC system is in the operating mode.

1 . A control assembly for a heating, ventilation, and/or air conditioning (HVAC) system, the control assembly comprising:
 a thermostat;   a sensor configured to detect a refrigerant leaked from the HVAC system; and   a controller configured to:
 receive, via the thermostat, a call for heating or cooling a space conditioned by the HVAC system; 
 operate, based on the call, a blower motor to cause a blower to circulate a first air flow across a coil of the HVAC system for a first time period based on a normal operating mode of the HVAC system; 
 receive, via the sensor, feedback indicative of the refrigerant leaked from the HVAC system; and 
 operate, based on the feedback, the blower motor to circulate a second air flow across the coil of the HVAC system for a second time period based on a detected leak mode of the HVAC system, wherein the detected leak mode differs from the normal operating mode. 
   
     
     
         2 . The control assembly of  claim 1 , wherein the first time period based on the normal operating mode includes a start time corresponding to activation of the blower motor and an end time corresponding to the call of the thermostat being satisfied. 
     
     
         3 . The control assembly of  claim 2 , comprising a sensor configured to detect a temperature in the space conditioned by the HVAC system, wherein the controller is configured to:
 receive, via the sensor, additional feedback indicative of the temperature in the space; and   identify, based on the additional feedback, the end time corresponding to the call of the thermostat being satisfied.   
     
     
         4 . The control assembly of  claim 1 , wherein:
 the first time period is dependent on additional feedback indicative of a temperature in the space; and   the second time period corresponds to a pre-defined time period.   
     
     
         5 . The control assembly of  claim 1 , wherein the second time period concludes with the detected leak mode being cleared. 
     
     
         6 . The control assembly of  claim 1 , wherein the coil corresponds to an evaporator coil. 
     
     
         7 . The control assembly of  claim 1 , wherein the controller is configured to block operation of a compressor of the HVAC system during the detected leak mode. 
     
     
         8 . The control assembly of  claim 1 , wherein the controller is configured to operate, based on the feedback, the blower motor to circulate the second air flow across the coil of the HVAC system for:
 the second time period based on the detected leak mode; and   after a delay period subsequent to the second time period, a third time period based on the detected leak mode.   
     
     
         9 . The control assembly of  claim 1 , wherein the first time period differs from the second time period. 
     
     
         10 . The control assembly of  claim 1 , wherein the sensor is configured to detect a concentration of the refrigerant leaked from a refrigerant circuit of the HVAC system into air, and the controller is configured to initiate the detected leak mode in response to determining that the concentration exceeds a threshold value. 
     
     
         11 . A heating, ventilation, and/or air conditioning (HVAC) system, comprising:
 a coil; and   a control assembly, comprising:
 a sensor configured to detect a refrigerant leaked from the HVAC system; and 
 a controller configured to:
 operate, based on a normal operating mode of the HVAC system, a blower assembly to circulate a first air flow across the coil; 
 receive, via the sensor, feedback indicative of the refrigerant leaked from the HVAC system; 
 initiate, based on the feedback, a detected leak mode; and 
 operate, based on the detected leak mode, the blower assembly to circulate a second air flow across the coil, wherein the detected leak mode differs from the normal operating mode in blower assembly operation time, blower assembly operation speed, or both. 
 
   
     
     
         12 . The HVAC system of  claim 11 , comprising a thermostat, wherein the controller is configured to initiate the normal operating mode in response to receiving, from the thermostat, a call for heating or cooling a space conditioned by the HVAC system. 
     
     
         13 . The HVAC system of  claim 12 , wherein the controller is configured to:
 operate, based on the normal operating mode of the HVAC system, the blower assembly to circulate the first air flow across the coil until the call is satisfied; and   operate, based on the detected leak mode, the blower assembly for a pre-defined time period or until the detected leak mode is cleared.   
     
     
         14 . The HVAC system of  claim 11 , wherein the sensor is configured to detect a concentration of the refrigerant leaked from a refrigerant circuit of the HVAC system into air, and the controller is configured to initiate, based on the feedback, the detected leak mode in response to determining that the concentration exceeds a threshold value. 
     
     
         15 . The HVAC system of  claim 11 , wherein the coil comprises an evaporator coil. 
     
     
         16 . One or more tangible, non-transitory, computer-readable media storing instructions thereon that, when executed by one or more processors, are configured to cause the one or more processors to:
 receive, via a thermostat, a call for heating or cooling a space conditioned by a heating, ventilation, and/or air conditioning (HVAC) system;   initiate a normal operating mode of the HVAC system based on the call;   operate, based on the normal operating mode, a blower assembly of the HVAC system to circulate a first air flow across a coil of the HVAC system;   receive, via a refrigerant concentration sensor, feedback indicative of a concentration of a refrigerant leaked from a refrigerant circuit of the HVAC system into air;   initiate a detected leak mode based on the feedback indicating that the concentration is greater than a threshold value; and   operate, based on the detected leak mode, the blower assembly to circulate a second air flow across the coil, wherein the detected leak mode differs from the normal operating mode in at least one operational aspect corresponding to the blower assembly.   
     
     
         17 . The one or more tangible, non-transitory, computer-readable media of  claim 16 , wherein the operational aspect includes a speed of the blower assembly. 
     
     
         18 . The one or more tangible, non-transitory, computer-readable media of  claim 16 , wherein the operational aspect includes an amount of time for operating the blower assembly. 
     
     
         19 . The one or more tangible, non-transitory, computer-readable media of  claim 16 , wherein the instructions, when executed by the one or more processors, are configured to cause the one or more processors to:
 display, on a user interface, a refrigerant leak alert based on the detected leak mode; or   transmit, to a user device, the refrigerant leak alert based on the detected leak mode.   
     
     
         20 . The one or more tangible, non-transitory, computer-readable media of  claim 16 , wherein the instructions, when executed by the one or more processors, are configured to cause the one or more processors to block operation of a compressor of the HVAC system based on the detected leak mode.