HVAC system operated with adaptive discharge air temperature setpoint
An HVAC system includes a blower, a variable-speed compressor, an indoor air temperature sensor that measures an indoor air temperature (IAT) of an enclosed space, and a controller. The controller stores an indoor temperature setpoint and a default discharge air temperature setpoint. The controller receives the IAT. The controller determines that the IAT is not within a threshold range of the indoor temperature setpoint. The controller then determines an adaptive discharge air temperature setpoint. The controller determines a compressor speed at which to operate the variable-speed compressor based on the adaptive discharge air temperature setpoint. The controller causes the variable-speed compressor to operate at the determined compressor speed.
1. A heating, ventilation and air conditioning (HVAC) system, comprising:
a variable-speed compressor configured to compress a refrigerant flowing through the HVAC system;
an indoor air temperature sensor positioned and configured to measure an indoor air temperature (IAT) of an enclosed space; and
a controller communicatively coupled to the variable-speed compressor, the indoor air temperature sensor, and a discharge air temperature sensor, the controller comprising:
a memory configured to store an indoor temperature setpoint and a default discharge air temperature setpoint; and
a processor configured to:
receive the IAT;
determine, based on a difference between the received IAT and the indoor temperature setpoint, that the IAT is not within a threshold range of the indoor temperature setpoint;
after determining that the IAT is not within the threshold range of the indoor temperature setpoint, determine an adaptive discharge air temperature setpoint based on the default discharge air temperature setpoint and the difference between the received IAT and the indoor temperature setpoint;
determine a compressor speed at which to operate the variable-speed compressor based on the adaptive discharge air temperature setpoint; and
cause the variable-speed compressor to operate at the determined compressor speed.
2. The system of claim 1 , wherein the processor is further configured to determine that the IAT is not within the threshold range of the indoor temperature setpoint when the IAT is greater than the indoor temperature setpoint.
3. The system of claim 1 , wherein:
the memory is further configured to store a default dehumidification mode discharge air temperature setpoint and a maximum temperature differential; and
the processor is further configured to determine the adaptive discharge air temperature setpoint based on the default discharge air temperature setpoint, the difference between the received IAT and the indoor temperature setpoint, the default dehumidification mode discharge air temperature setpoint, and the maximum temperature differential.
4. The system of claim 3 , wherein the processor is further configured to determine the compressor speed based on a difference between a discharge air temperature and the adaptive discharge air temperature setpoint.
5. The system of claim 4 , wherein:
the HVAC system further comprises a second compressor; and
the processor is further configured to:
determine that the determined compressor speed is greater than a maximum speed of the variable-speed compressor;
after determining that the determined compressor speed is greater than the maximum speed of the variable-speed compressor:
cause the variable-speed compressor to operate at the maximum speed; and
cause the second compressor to activate.
6. The system of claim 5 , wherein following causing the variable-speed compressor to operate at the determined compressor speed, the IAT is within a threshold value of the indoor temperature setpoint within a threshold time.
7. The system of claim 6 , wherein the processor is further configured to:
determine a blower speed at which to operate a blower based on the received IAT and the indoor temperature setpoint; and
cause the blower to operate at the determined blower speed.
8. A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to:
receive an indoor air temperature (IAT) of an enclosed space to which conditioned air is provided by a heating, ventilation and air conditioning (HVAC) system;
determine, based on a difference between the received IAT and an indoor temperature setpoint, that the IAT is not within a threshold range of the indoor temperature setpoint;
after determining that the IAT is not within the threshold range of the indoor temperature setpoint, determine an adaptive discharge air temperature setpoint based on a default discharge air temperature setpoint and the difference between the received IAT and the indoor temperature setpoint;
determine a compressor speed at which to operate a variable-speed compressor of an HVAC system based on the adaptive discharge air temperature setpoint; and
cause the variable-speed compressor to operate at the determined compressor speed.
9. The non-transitory computer-readable medium of claim 8 , wherein the instructions further cause the processor to determine that the IAT is not within the threshold range of the indoor temperature setpoint when the IAT is greater than the indoor temperature setpoint.
10. The non-transitory computer-readable medium of claim 8 , wherein the instructions further cause the processor to determine the adaptive discharge air temperature setpoint based on the default discharge air temperature setpoint, the difference between the received IAT and the indoor temperature setpoint, a default dehumidification mode discharge air temperature setpoint, and a maximum temperature differential.
11. The non-transitory computer-readable medium of claim 10 , wherein the instructions further cause the processor to determine the compressor speed based on a difference between a discharge air temperature and the adaptive discharge air temperature setpoint.
12. The non-transitory computer-readable medium of claim 11 , wherein the instructions further cause the processor to:
determine that the determined compressor speed is greater than a maximum speed of the variable-speed compressor; and
after determining that the determined compressor speed is greater than the maximum speed of the variable-speed compressor:
cause the variable-speed compressor to operate at the maximum speed; and
cause a second compressor of the HVAC system to activate.
13. The non-transitory computer-readable medium of claim 12 , wherein the instructions further cause the processor to: wherein following causing the variable-speed compressor to operate at the determined compressor speed, the IAT is within a threshold value of the indoor temperature setpoint within a threshold time.
14. The non-transitory computer-readable medium of claim 13 , wherein the instructions further cause the processor to:
determine a blower speed at which to operate a blower of the HVAC system based on the received IAT and the indoor temperature setpoint; and
cause the blower to operate at the determined blower speed.