Leakage detection system for a2l class refrigerants

Abstract

An air delivery system comprises an air handler enclosure having an inlet for enabling air to flow into the air handler enclosure and an outlet exhaust air out of the air handler enclosure. A blower is located in the air handler enclosure for drawing air through the inlet and exhausting air from the outlet. The system includes at least one sensor A2L refrigerant sensor for sensing the concentration of A2L refrigerant in the air delivery system, at least one auxiliary fan, and a controller is provided for receiving data from the A2L sensor, and powering the at least one auxiliary fan to reduce the concentration of A2L refrigerant below a predetermined threshold level.

What is claimed is: 
     
         1 . An air delivery system comprising: an air handler enclosure having an inlet for enabling air to flow into the air handler enclosure and an outlet exhaust air out of the air handler enclosure, a blower located in the air handler enclosure for drawing air through the inlet and exhausting air from the outlet, at least one sensor A2L refrigerant sensor for sensing the concentration of A2L refrigerant in the air delivery system, at least one auxiliary fan, and a controller for receiving data from the A2L sensor, and powering the at least one auxiliary fan to reduce the concentration of A2L refrigerant below a predetermined threshold level. 
     
     
         2 . The air delivery system of  claim 1  wherein the at least one auxiliary fan is located at the inlet. 
     
     
         3 . The air delivery system as claimed in  claim 1  wherein the at least one auxiliary fan is located at the outlet. 
     
     
         4 . The air delivery system as claimed in  claim 1  wherein the at least one auxiliary fan is located at the air handler. 
     
     
         5 . The at least one auxiliary fan comprises three auxiliary fans, one auxiliary fan located at the inlet, one auxiliary fan located at the outlet and one auxiliary fan located along the air handler enclosure. 
     
     
         6 . The air delivery system as claimed in  claim 1  wherein the at least one auxiliary fan is located at the outlet and the at least one A2L sensor is located proximate the at least one auxiliary fan. 
     
     
         7 . The air delivery system as claimed in  claim 1  wherein the at least one auxiliary fan is located at the inlet and the at least one A2L sensor is located proximate the at least one auxiliary fan. 
     
     
         8 . The air delivery system as claimed in  claim 1  wherein the at least one auxiliary fan is located along the air handler enclosure, and the at least one A2L sensor is located proximate the at least one auxiliary fan. 
     
     
         9 . The air delivery system as claimed in  claim 1  wherein the at least one auxiliary fan comprises three auxiliary fans, one auxiliary fan located at the inlet, one auxiliary fan located at the outlet and one auxiliary fan located along the air handler enclosure, and the at least one A2L sensor comprises three sensors each of the at least one sensors being located proximate each of the at least one auxiliary fans. 
     
     
         10 . The air delivery system as claimed in  claim 1  wherein the blower has an adjustable rotary speed, the controller configured to reduce the blower speed when the concentration of A2L is above the predetermined threshold level. 
     
     
         11 . A method of operating an air delivery system wherein the air delivery system comprises a blower, at least one sensor for sensing A2L refrigerant concentration in the air, and a controller for receiving data from the sensor representing the A2L refrigerant concentration and controlling operation of the blower, the method comprising:
 a. sensing the concentration of A2L refrigerant in the delivered air;   b. sending data representing the sensed concentration of A2L refrigerant to the controller;   c. processing the data to determine if the concentration of A2L refrigerant has exceeded a threshold concentration limit; and   d. if the concentration of A2L refrigerant exceeds a threshold limit, controlling the air delivery system and instructing the air delivery system to perform a mitigating operation to reduce the A2L refrigerant concentration below the threshold level.   
     
     
         12 . The method of operating an air delivery system, as claimed in  claim 11 , wherein the mitigation operation comprises lowering the rotational speed of the blower. 
     
     
         13 . The method of operating an air delivery system, as claimed in  claim 12  wherein the air delivery system comprises a compressor for delivering refrigerant to the air delivery system, the mitigation operation comprising turning shutting off the power to the compressor until the A2L refrigerant concentration is below a threshold level. 
     
     
         14 . The method of operating an air delivery system as claimed in  claim 11  wherein the air delivery system further comprises an auxiliary fan, the mitigating operation comprising sending a control signal to the auxiliary fan to reduce the A2L refrigerant concentration below a threshold level. 
     
     
         15 . The method of operating an air delivery system as claimed in  claim 11  wherein the air delivery system further comprises an air handler enclosure having an inlet for enabling air to flow into the air handler enclosure and an outlet exhaust air out of the air handler enclosure, the blower located in the air handler enclosure, auxiliary fans located at the inlet, outlet and along the air handler enclosure, the mitigating operation comprising powering one or more of the auxiliary fans to reduce the A2L concentration below a threshold level. 
     
     
         16 . The method of operating an air delivery system as claimed in  claim 11  wherein the air delivery system further comprises an air handler enclosure having an inlet for enabling air to flow into the air handler enclosure and an outlet exhaust air out of the air handler enclosure, the blower located in the air handler enclosure, an auxiliary fan located at the inlet, the mitigating operation comprising powering the auxiliary fan to reduce the A2L concentration below a threshold level. 
     
     
         17 . The method of operating an air delivery system as claimed in  claim 11  wherein the air delivery system further comprises an air handler enclosure having an inlet for enabling air to flow into the air handler enclosure and an outlet exhaust air out of the air handler enclosure, the blower located in the air handler enclosure, an auxiliary fan located at the outlet, the mitigating operation comprising powering the auxiliary fan to reduce the A2L concentration below a threshold level. 
     
     
         18 . The method of operating an air delivery system as claimed in  claim 11  wherein the air delivery system further comprises an air handler enclosure having an inlet for enabling air to flow into the air handler enclosure and an outlet exhaust air out of the air handler enclosure, the blower located in the air handler enclosure, an auxiliary fan located along the air handler enclosure, the mitigating operation comprising powering the auxiliary fan to reduce the A2L concentration below a threshold level.