Refrigerant detection for a cooling system

Abstract

A heating, ventilation, and air conditioning (HVAC) system is disclosed, featuring an evaporator coil that receives airflow and transfers heat to a refrigerant flow. Positioned beneath the evaporator coil is a drain pan with a base and two vertically extending sides. A main support is located between the drain pan and an air filter, extending vertically to create a space adjacent to one side of the drain pan, and includes a hole. A housing is mounted against the main support such that any refrigerant leaking from the evaporator coil, which overflows the drain pan and accumulates in the defined space, is directed through the hole into the housing. The system further includes a compressor that receives refrigerant from the evaporator coil and discharges it at elevated pressure. A refrigerant detection sensor is positioned within the housing to monitor and detect refrigerant concentration within the housing volume.

1 . A heating, ventilation, and air conditioning (HVAC) system, comprising:
 an evaporator coil configured to receive an airflow and to transfer heat from the received airflow to a flow of refrigerant;   a drain pan disposed underneath the evaporator coil, wherein the drain pan comprises a base, a first side extending vertically from the base, and a second side extending vertically from the base;   a main support disposed between the drain pain and an air filter, wherein the main support extends vertically to define a space between the main support and the first side of the drain pan, wherein the main support includes a hole;   a housing disposed against the main support such that any leaked refrigerant that overflows the first side of the drain pan and that accumulates in the space, flows into the housing through the hole;   a compressor configured to receive the flow of refrigerant from the evaporator coil and to discharge the flow of refrigerant at a higher pressure; and   a refrigerant detection sensor disposed within the housing and configured to detect a concentration of refrigerant in a volume defined by the housing.   
     
     
         2 . HVAC system of  claim 1 , wherein the housing is disposed between the evaporator coil and an air filter. 
     
     
         3 . The HVAC system of  claim 2 , wherein the hole is vertically offset from the refrigerant detection sensor. 
     
     
         4 . The HVAC system of  claim 3 , further comprising a blower stand disposed adjacent to the drain pan opposite from the housing, wherein the blower is disposed on top of the blower stand. 
     
     
         5 . The HVAC system of  claim 1 , wherein the refrigerant is classified as an A2L refrigerant. 
     
     
         6 . The HVAC system of  claim 1 , further comprising a condensing unit configured to reject heat from the flow of refrigerant, wherein the condensing unit comprises a condenser and at least one fan. 
     
     
         7 . A heating, ventilation, and air conditioning (HVAC) system, comprising:
 an evaporator coil configured to receive an airflow and to transfer heat from the received airflow to a flow of refrigerant;   a drain pan disposed underneath the evaporator coil, wherein the drain pan comprises a base, a first side extending vertically from the base, and a second side extending vertically from the base;   a main support disposed between the drain pain and an air filter, wherein the main support extends vertically to define a space between the main support and the first side of the drain pan, wherein the main support includes a hole;   a housing disposed against the main support such that any leaked refrigerant that overflows the first side of the drain pan and that accumulates in the space, flows into the housing through the hole;   a compressor configured to receive the flow of refrigerant from the evaporator coil and to discharge the flow of refrigerant at a higher pressure;   a refrigerant detection sensor disposed within the housing and configured to detect a concentration of refrigerant in a volume defined by the housing; and   a controller operably coupled to the refrigerant detection sensor and configured to turn off the compressor and to actuate a blower to discharge the airflow when the concentration of refrigerant in the volume exceeds a threshold value associated with a lower flammability limit of the refrigerant.   
     
     
         8 . HVAC system of  claim 7 , wherein the housing is disposed between the evaporator coil and an air filter. 
     
     
         9 . The HVAC system of  claim 8 , wherein the hole is vertically offset from the refrigerant detection sensor. 
     
     
         10 . The HVAC system of  claim 9 , further comprising a blower stand disposed adjacent to the drain pan opposite from the housing, wherein the blower is disposed on top of the blower stand. 
     
     
         11 . The HVAC system of  claim 7 , wherein the refrigerant is classified as an A2L refrigerant. 
     
     
         12 . The HVAC system of  claim 7 , further comprising a condensing unit configured to reject heat from the flow of refrigerant, wherein the condensing unit comprises a condenser and at least one fan. 
     
     
         13 . The HVAC system of  claim 7 , wherein the blower is disposed proximate to the evaporator coil.