Patent ID: 11927362
Assignee: LENNOX INDUSTRIES INC.
Field: Thermal processes and apparatus (Mechanical engineering)
Classification: CPC F  G  Y | IPC F  G

Claim 0:
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.