US 11,859,849 B2
HVAC systems with evaporator bypass and supply air recirculation and methods of using same
Rakesh Goel, Irving, TX (US); and Vijay Sathyamurthi, Frisco, TX (US)
Assigned to Lennox Industries Inc., Richardson, TX (US)
Filed by Lennox Industries Inc., Richardson, TX (US)
Filed on Oct. 19, 2022, as Appl. No. 18/047,837.
Application 18/047,837 is a continuation of application No. 17/156,211, filed on Jan. 22, 2021, granted, now 11,549,714.
Application 17/156,211 is a continuation of application No. 16/356,841, filed on Mar. 18, 2019, granted, now 10,941,958, issued on Mar. 9, 2021.
Prior Publication US 2023/0063742 A1, Mar. 2, 2023
Int. Cl. F24F 11/81 (2018.01); F24F 3/14 (2006.01); F24F 11/65 (2018.01); F24F 3/048 (2006.01); F24F 110/20 (2018.01); F24F 110/10 (2018.01)
CPC F24F 11/81 (2018.01) [F24F 3/14 (2013.01); F24F 11/65 (2018.01); F24F 3/048 (2013.01); F24F 2003/144 (2013.01); F24F 2110/10 (2018.01); F24F 2110/20 (2018.01)] 15 Claims
OG exemplary drawing
 
1. A heating, ventilation, and air conditioning (HVAC) system comprising:
an evaporator coil disposed between a return air duct and a supply air duct;
a compressor fluidically connected to the evaporator coil;
a blower disposed between the evaporator and the supply air duct, wherein the blower provides a flow of air through the HVAC system;
an evaporator bypass line fluidically connecting the return air duct to an output airstream of the evaporator coil, the evaporator bypass line comprising a bypass damper for adjusting a first flow of air to an input of the evaporator coil and a second flow of air to the output airstream of the evaporator coil via the evaporator bypass line; and
a controller operatively coupled to the compressor, the blower, the recirculation damper, and the bypass damper, the controller operable to:
determine an operating mode of the HVAC system;
determine a predetermined threshold ratio value for the operating mode;
determine whether a ratio of a minimum operating flow rate of the blower to a speed of the compressor is greater than the predetermined threshold ratio value for the operating mode; and
responsive to a determination that the ratio is greater than the predetermined threshold ratio value, determine a bypass portion of the first flow of air to divert from the return air duct to the output airstream of the evaporator coil based on the speed of the compressor and the predetermined threshold ratio value for the operating mode.