CPC F24F 3/1405 (2013.01) [F24F 3/153 (2013.01); F25B 47/006 (2013.01); G05B 15/02 (2013.01); F24F 2003/144 (2013.01)] | 19 Claims |
1. A method of preventing evaporator coil freeze in a heating, ventilation and air conditioning (HVAC) system operating in re-heat dehumidification mode, the method comprising:
determining, by a controller, a reference saturated suction temperate (SST) via a sensor disposed on an exterior surface of an evaporator coil in the HVAC system, the evaporator coil comprises a plurality of evaporator circuits assigned to a plurality of compressors in the HVAC system, wherein the determining the reference SST comprises determining a plurality of SSTs via a plurality of sensors disposed in relation to the evaporator coil and determining a minimum SST of the plurality of SSTs, wherein the minimum SST is the reference SST;
determining, by the controller, whether the reference SST is below a minimum SST threshold;
responsive to a determination that the reference SST is below the minimum SST threshold, determining a decreased compressor speed; and
modulating, by the controller, a variable-speed compressor in the HVAC system to operate at the decreased compressor speed, the decreased compressor speed varies at least one of linearly and non-linearly with the reference SST between a first value and a second value.
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