Method of operating a makeup air module of an air conditioner unit

Abstract

An air conditioning system includes a refrigeration loop includes an indoor fan operable to urge an inlet flow of indoor air through an indoor heat exchanger, an auxiliary fan operable to urge an outdoor makeup air flow to combine with the inlet flow to produce a mixed discharge air flow, and a controller. The controller is configured to operate a compressor at a first compressor speed, operate the indoor fan at a first indoor fan speed, operate the auxiliary fan at a first auxiliary fan speed, determine a temperature of the inlet flow of indoor air, determine a temperature of the mixed discharge air flow, determine that a temperature differential between the inlet flow temperature and the mixed discharge flow temperature deviates from a predetermined range, and implement a responsive action in response to determining the temperature differential deviates from the predetermined range.

What is claimed is: 
     
         1 . An air conditioning system comprising:
 a refrigeration loop comprising an indoor heat exchanger and an outdoor heat exchanger;   a compressor operably coupled to the refrigeration loop and being configured to urge refrigerant through the refrigeration loop;   an indoor fan operable to urge an inlet flow of indoor air through the indoor heat exchanger;   an auxiliary fan operable to urge an outdoor makeup air flow to combine with the inlet flow to produce a mixed discharge air flow; and   a controller operably coupled to the compressor, the indoor fan, and the auxiliary fan, the controller being configured to:
 operate the compressor at a first compressor speed; 
 operate the indoor fan at a first indoor fan speed; 
 operate the auxiliary fan at a first auxiliary fan speed; 
 determine a temperature of the inlet flow of indoor air; 
 determine a temperature of the mixed discharge air flow; 
 determine that a temperature differential between the inlet flow temperature and the mixed discharge flow temperature deviates from a predetermined range; and 
 implement a responsive action in response to determining the temperature differential deviates from the predetermined range. 
   
     
     
         2 . The air conditioning system of  claim 1 , further comprising:
 an inlet temperature sensor in operable communication with the controller and positioned in the inlet flow of indoor air;   a discharge temperature sensor in operable communication with the controller and positioned in the mixed discharge air flow;   wherein the inlet temperature sensor communicates to the controller an inlet air temperature signal corresponding to a temperature of the inlet air flow;   the discharge temperature sensor communicates to the controller a discharge air temperature signal corresponding to a temperature of the mixed discharge air flow; and   the controller determines the temperature differential from the inlet air temperature signal and the discharge air temperature signal.   
     
     
         3 . The air conditioning system of  claim 2 , wherein determining the temperature differential comprises subtracting the temperature of the mixed discharge air flow from the temperature of the inlet air flow. 
     
     
         4 . The air conditioning system of  claim 2 , wherein inlet temperature sensor is positioned in the inlet flow of indoor air upstream of the indoor heat exchanger. 
     
     
         5 . The air conditioning system of  claim 1 , wherein:
 the compressor is a variable speed compressor; and   implementing the responsive action comprises increasing the first compressor speed to a second compressor speed.   
     
     
         6 . The air conditioning system of  claim 5 , wherein the first compressor speed is increased at a predetermined compressor ramp-up rate. 
     
     
         7 . The air conditioning system of  claim 6 , wherein:
 the predetermined compressor ramp-up rate is about 100 revolutions per minute per minute; and   the second compressor speed is less than about 6,000 revolutions per minute.   
     
     
         8 . The air conditioning system of  claim 1 , wherein:
 the auxiliary fan is a variable speed fan; and   implementing the responsive action comprises decreasing the first auxiliary fan speed to a second auxiliary fan speed.   
     
     
         9 . The air conditioning system of  claim 1 , further comprising:
 a damper positioned in the outdoor makeup air flow, the damper movable between a first position allowing a flow of outdoor makeup air and a second position blocking the flow of outdoor makeup air; and   
       wherein implementing the responsive action comprises moving the damper to the second position. 
     
     
         10 . The air conditioning system of  claim 1 , further comprising:
 a reversing valve fluidly coupled to the refrigeration loop and selectively movable between a first position corresponding to a cooling mode and a second position corresponding to a heating mode; and   a supplemental heat source; and wherein implementing the responsive action in the heating mode comprises energizing the supplemental heat source.   
     
     
         11 . A method of operating an air conditioning system comprising a refrigeration loop comprising an indoor heat exchanger, an outdoor heat exchanger, a compressor configured to urge refrigerant through the refrigeration loop, an indoor fan operable to urge an inlet flow of indoor air through the indoor heat exchanger, and an auxiliary fan operable to urge an outdoor makeup air flow to combine with the inlet flow to produce a mixed discharge air flow, the method comprising:
 operating the compressor at a first compressor speed;   operating the indoor fan at a first indoor fan speed;   operating the auxiliary fan at a first auxiliary fan speed;   determining a temperature of the inlet flow of indoor air;   determining a temperature of the mixed discharge air flow;
 determining that a temperature differential between the inlet flow temperature and the mixed discharge flow temperature deviates from a predetermined range; and 
 implementing a responsive action in response to determining the temperature differential deviates from the predetermined range. 
   
     
     
         12 . The method of  claim 11 , wherein determining the temperature differential between the inlet flow temperature and the discharge flow temperature comprises:
 receiving an inlet air temperature signal corresponding to a temperature of the inlet air flow;   receiving a discharge air temperature signal corresponding to a temperature of the mixed discharge air flow; and   determining the temperature differential from the inlet air temperature signal and the discharge air temperature signal.   
     
     
         13 . The method of  claim 12 , wherein:
 the inlet air temperature signal is received from a temperature sensor positioned in the inlet flow of indoor air; and   the discharge air temperature signal is received from a discharge temperature senor positioned in the mixed discharge air flow.   
     
     
         14 . The method of  claim 13 , wherein determining the temperature differential comprises subtracting the temperature of the mixed discharge air flow from the temperature of the inlet air flow. 
     
     
         15 . The method of  claim 11 , wherein:
 the compressor is a variable speed compressor; and   implementing the responsive action comprises increasing the first compressor speed to a second compressor speed.   
     
     
         16 . The method of  claim 15 , wherein the first compressor speed is increased at a predetermined ramp-up rate. 
     
     
         17 . The method of  claim 16 , wherein:
 the predetermined ramp-up rate is about 100 revolutions per minute per minute; and   the second compressor speed is less than about 6,000 revolutions per minute.   
     
     
         18 . The method of  claim 11 , wherein:
 the auxiliary fan is a variable speed fan; and   implementing the responsive action comprises decreasing the first auxiliary fan speed to a second auxiliary fan speed.   
     
     
         19 . The method of  claim 11 , wherein:
 the air conditioning system further comprises a damper positioned in the outdoor makeup air flow, the damper movable between a first position allowing a flow of outdoor makeup air and a second position blocking the flow of outdoor makeup air; and   implementing the responsive action comprises moving the damper to the second position.   
     
     
         20 . The method of  claim 11 , wherein:
 the air conditioning system further comprises:
 a reversing valve fluidly coupled to the refrigeration loop and selectively movable between a first position corresponding to a cooling mode and a second position corresponding to a heating mode; and 
 a supplemental heat source; and wherein 
   implementing the responsive action in the heating mode comprises energizing the supplemental heat source.