Safety System For Air Handling Unit

Abstract

The present disclosure provides an interface control relay module including a refrigerant sensor input connected to a refrigerant sensor of an air handling unit (AHU) that generates an input proportional to a concentration of a refrigerant leak in the AHU. The relay module further includes a control unit coupled to the refrigerant sensor input to receive the input from the refrigerant sensor; a first relay output and a second relay output, each connecting the control unit to a cooling unit of the AHU; a third relay output connecting the control unit to a fan of the AHU; and a fourth relay output connecting the control unit to a damper of the AHU. The control unit activates or deactivates at least one of the first relay output, the second relay output, the third relay output and the fourth relay output based on the input received from the refrigerant sensor.

What is claimed is: 
     
         1 . An interface control relay module comprising:
 a refrigerant sensor input connected to a refrigerant sensor of an air handling unit (AHU), the refrigerant sensor configured to generate an input proportional to a concentration of a refrigerant leak sensed in the AHU;   a control unit coupled to the refrigerant sensor input and configured to receive the input from the refrigerant sensor;   a first relay output and a second relay output, each connecting the control unit to a cooling unit of the AHU;   a third relay output connecting the control unit to a fan of the AHU; and   a fourth relay output connecting the control unit to a damper of the AHU,   wherein the control unit is configured to activate or deactivate at least one of the first relay output, the second relay output, the third relay output and the fourth relay output based on the input received from the refrigerant sensor.   
     
     
         2 . The interface control relay module of  claim 1 , wherein the control unit is configured to determine a degree of refrigerant leak based on comparing the concentration of the refrigerant leak to a predefined threshold value. 
     
     
         3 . The interface control relay module of  claim 2 , wherein the control unit is configured to deactivate at least one of the third relay output and the fourth relay output when the concentration of the refrigerant leak is below the predefined threshold value. 
     
     
         4 . The interface control relay module of  claim 1 , further comprising a fifth relay output and a sixth relay output, each connected to a heating unit of the AHU, wherein the control unit is configured to activate or deactivate the fifth relay output and the sixth relay output to turn on or turn off the heating unit. 
     
     
         5 . The interface control relay module of  claim 1 , further comprising an airflow sensor of the AHU, the airflow sensor configured to generate an input indicative of an amount of airflow produced by the fan. 
     
     
         6 . A safety system for an air handling unit (AHU) comprising a heating unit and a cooling unit, the safety system comprising:
 a refrigerant sensor coupled to the AHU, wherein the refrigerant sensor is configured to generate an input proportional to a concentration of a refrigerant leak sensed in the AHU;   an interface control relay module comprising:
 a refrigerant sensor input connected to the refrigerant sensor; 
 a control unit coupled to the refrigerant sensor input and configured to receive the input from the refrigerant sensor; 
 a first relay output and a second relay output, each connecting the control unit to a cooling unit of the AHU; 
 a third relay output connecting the control unit to a fan of the AHU; and 
 a fourth relay output connecting the control unit to a damper of the AHU, 
 wherein the control unit is configured to activate or deactivate at least one of 
   the first relay output, the second relay output, the third relay output and the fourth relay output based on the input received from the refrigerant sensor.   
     
     
         7 . The safety system of  claim 6 , wherein the control unit is configured to determine a degree of refrigerant leak based on comparing the concentration of the refrigerant leak to a predefined threshold value. 
     
     
         8 . The safety system of  claim 7 , wherein the control unit is configured to deactivate at least one of the third relay output and the fourth relay output when the concentration of the refrigerant leak is below the predefined threshold value. 
     
     
         9 . The safety system of  claim 6 , wherein the interface control relay module further comprises a fifth relay output and a sixth relay output, each connected to the heating unit, wherein the control unit is configured to activate or deactivate the fifth relay output and the sixth relay output to turn on or turn off the heating unit. 
     
     
         10 . The safety system of  claim 7 , further comprising a smoke detector alarm, wherein the control unit is configured to trigger the smoke detector alarm when the refrigerant leak is detected. 
     
     
         11 . The safety system of  claim 7 , further comprising a processing unit configured to monitor the interface control relay module and trigger an alert when the refrigerant leak is detected. 
     
     
         12 . The safety system of  claim 7 , further comprising an airflow sensor of the AHU, the airflow sensor configured to generate an input indicative of an amount of airflow produced by the fan. 
     
     
         13 . A method of operating an air handling unit (AHU), the method comprising:
 monitoring an input from a refrigerant sensor, the input indicating concentration of a refrigerant leak sensed in the AHU;   comparing, by a control unit, the concentration of the refrigerant leak with a predefined threshold value;   determining, by the control unit, a degree of refrigerant leak in the AHU based on the comparison; and   activating or deactivating, by the control unit, at least one of a first relay output, a second relay output, a third relay output and a fourth relay output based on the degree of refrigerant leak, wherein the first relay output and the second relay output connects the control unit to a cooling unit of the AHU, the third relay output connects the control unit to a fan of the AHU, and a fourth relay output connects the control unit to a damper of the AHU.   
     
     
         14 . The method of  claim 13 , further comprising, deactivating the first relay output and the second relay output, and stopping operation of the cooling unit when the concentration of the refrigerant leak exceeds the predefined threshold value. 
     
     
         15 . The method of  claim 13 , further comprising, activating at least one of the third relay output and the fourth relay output to initiate the fan or the damper, and dispersing the leaked refrigerant. 
     
     
         16 . The method of  claim 13 , further comprising deactivating, by the control unit, at least one of the third relay output and the fourth relay output when the concentration of refrigerant leak is below the predefined threshold value. 
     
     
         17 . The method of  claim 13 , further comprising, activating, or deactivating a fifth relay output and a sixth relay output to turn on or turn off the heating unit, wherein each of the fifth relay output and a sixth relay output is connected to a heating unit of the AHU. 
     
     
         18 . The method of  claim 13 , further comprising triggering, via a processing unit, a smoke detector alarm in response to the refrigerant leak.