Method and system for compressor modulation in non-communicating mode
An HVAC system includes a pressure sensor is disposed in a suction line between a compressor and an indoor heat-exchange coil. The pressure sensor is electrically coupled to a compressor controller. An HVAC controller is electrically coupled to the compressor controller. The HVAC controller is configured to transmit a signal to the compressor controller to activate and de-activate the compressor. The compressor controller is configured to receive a signal from the HVAC controller to activate the compressor, determine a start speed of the compressor, monitor a run time of the compressor, and modulate a speed of the compressor.
1. A heating, ventilation, and air-conditioning (HVAC) system comprising:
an indoor unit comprising:
an indoor heat-exchange coil;
an indoor circulation fan arranged to circulate air through the indoor heat-exchange coil;
a metering device fluidly coupled to the indoor heat-exchange coil;
an outdoor unit comprising:
an outdoor heat-exchange coil;
an outdoor circulation fan arranged to circulate air through the outdoor heat-exchange coil;
a compressor fluidly coupled to the outdoor heat-exchange coil and fluidly coupled to the indoor heat-exchange coil;
a compressor controller electrically coupled to the compressor;
a pressure sensor disposed in a suction line between the compressor and the indoor heat-exchange coil, the pressure sensor being electrically coupled to the compressor controller;
an HVAC controller electrically coupled to the compressor controller, the HVAC controller configured to transmit a signal to the compressor controller to at least one of activate and de-activate the compressor;
the compressor controller configured to:
receive a signal from the HVAC controller to activate the compressor;
determine a start speed of the compressor;
monitor a run time of the compressor relative to a minimum run time and a desired cycle time;
modulate a speed of the compressor to maintain a desired suction pressure; and
responsive to a determination that the desired cycle time has been reached, increase the speed of the compressor to lower the desired suction pressure.
2. The HVAC system of claim 1 , wherein the HVAC system operates in at least one of an air-conditioning mode and a heating mode.
3. The HVAC system of claim 2 , wherein, when the HVAC system operates in the air-conditioning mode, the compressor controller modulates the speed of the compressor responsive to a suction pressure measured by the pressure sensor.
4. The HVAC system of claim 2 , comprising at least one of:
a temperature sensor disposed in a discharge line between the compressor and the outdoor heat-exchange coil, the temperature sensor being electrically coupled to the compressor controller; and
a pressure sensor disposed in the discharge line, the pressure sensor being electrically coupled to the compressor controller.
5. The HVAC system of claim 4 , wherein, when the HVAC system operates in the heating mode, the compressor controller modulates the speed of the compressor responsive to a refrigerant temperature in a discharge line measured by the temperature sensor.
6. The HVAC system of claim 4 , wherein, when the HVAC system operates in the heating mode, the compressor controller modulates the speed of the compressor responsive to a refrigerant pressure in the discharge line measured by the pressure sensor.
7. A compressor system comprising:
an outdoor heat-exchange coil;
an outdoor circulation fan disposed arranged to circulate air through the outdoor heat-exchange coil;
a compressor fluidly coupled to the outdoor heat-exchange coil;
a compressor controller electrically coupled to the compressor, the compressor controller configured to:
receive a signal from an HVAC controller to activate the compressor;
determine a start speed of the compressor;
monitor a run time of the compressor relative to a minimum run time and a desired cycle time;
modulate a speed of the compressor to maintain a desired suction pressure; and
responsive to a determination that the desired cycle time has been reached, increase the speed of the compressor to lower the desired suction pressure.
8. The compressor system of claim 7 , comprising a pressure sensor disposed on a suction side of the compressor.
9. The compressor system of claim 7 , comprising at least one of a temperature sensor and a pressure sensor disposed on a discharge side of the compressor.
10. The compressor system of claim 7 , wherein the compressor system is coupled to an indoor unit of an HVAC system that operates in at least one of an air-conditioning mode and a heating mode.
11. The compressor system of claim 10 , wherein, when the HVAC system operates in the air-conditioning mode, the compressor controller modulates the speed of the compressor responsive to a suction pressure measured by a pressure sensor.
12. The compressor system of claim 10 , wherein, when the HVAC system operates in the heating mode, the compressor controller modulates the speed of the compressor responsive to at least one of a refrigerant temperature in a discharge line measured by a temperature sensor and a refrigerant pressure in the discharge line measured by a pressure sensor.
13. The compressor system of claim 10 , wherein the HVAC controller increases the speed of the compressor responsive to the run time of the compressor exceeding a desired cycle time of the HVAC system.
14. The compressor system of claim 7 , wherein the signal received from the HVAC controller is a 24 VAC signal.
15. A method of modulating a speed of a compressor, the method comprising:
receiving a signal from an HVAC controller to at least one of activate and de-activate a compressor;
determining a start speed of the compressor;
activating the compressor at the determined start speed;
monitoring a run time of the compressor;
comparing the run time of the compressor to a minimum run time and a desired cycle time of an HVAC system;
modulate a speed of the compressor to maintain a desired suction pressure; and
responsive to a determination that the desired cycle time has been reached, increase the speed of the compressor to lower the desired suction pressure.
16. The method of claim 15 , wherein the modulating the speed of the compressor comprises modulating the speed of the compressor responsive to a suction pressure measured by a pressure sensor when the HVAC system is operating in an air-conditioning mode.
17. The method of claim 15 , wherein the modulating the speed of the compressor comprises modulating the speed of the compressor responsive to at least one of a discharge refrigerant temperature measured by a temperature sensor and a discharge refrigerant pressure measured by a pressure sensor when the HVAC system is operating in a heating mode.
18. The method of claim 15 , comprising increasing the speed of the compressor responsive to the run time exceeding the desired cycle time of the HVAC system.
19. The method of claim 15 , comprising decreasing the start speed of the compressor responsive to the run time being below a minimum threshold.
20. The method of claim 15 , wherein the signal received from the HVAC controller is a 24 VAC signal.