US 11,708,981 B2
High-pressure re-start control algorithm for microchannel condenser with reheat coil
Colin Clara, Frisco, TX (US); Eric Perez, Hickory Creek, TX (US); and Walter E. Davis, II, Dallas, TX (US)
Assigned to Lennox Industries Inc., Richardson, TX (US)
Filed by Lennox Industries Inc., Richardson, TX (US)
Filed on Mar. 22, 2021, as Appl. No. 17/208,795.
Application 17/208,795 is a division of application No. 15/362,316, filed on Nov. 28, 2016, granted, now 11,022,331.
Prior Publication US 2021/0207823 A1, Jul. 8, 2021
Int. Cl. F24F 3/153 (2006.01); F25B 41/20 (2021.01); F24F 3/14 (2006.01)
CPC F24F 3/153 (2013.01) [F25B 41/20 (2021.01); F24F 3/1405 (2013.01); F25B 2600/17 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method of controlling a heating, ventilation and air conditioning (HVAC) system, the method comprising:
receiving a request to start operation of the HVAC system;
using a valve to direct refrigerant from a compressor through a second branch of the valve into a reheat coil at startup, thereby causing the HVAC system to operate in a reheat mode, wherein the valve comprises a valve input connected to the compressor, a first branch connected to a micro-channel condenser, the second branch connected to the reheat coil, and a third branch connected to a low pressure refrigerant line, wherein the low pressure refrigerant line directly connects an evaporator to the compressor;
operating in the reheat mode for a predetermined amount of time to prevent high pressure conditions at an input to the micro-channel condenser and after operating in the reheat mode for the predetermined amount of time:
using the valve, in a normal mode, to direct the refrigerant from the compressor through the first branch of the valve to the input to the micro-channel condenser; and
using the valve, in the normal mode, to direct the refrigerant from the reheat coil through the second branch of the valve, out of the third branch of the valve, and to the low pressure refrigerant line through a restrictor located between the third branch of the valve and the low pressure refrigerant line directly connecting the evaporator to the compressor.