US 12,253,284 B2
Systems and methods for operating a furnace
James R. M. Neal, Tyler, TX (US); Thomas Gort, Tyler, TX (US); Wayne N. Kraft, Tyler, TX (US); Sandeep Gowdagiri, Tyler, TX (US); Neal Harrington, Tyler, TX (US); and David Williams, Jr., Tyler, TX (US)
Assigned to Trane International Inc., Davidson, NC (US)
Filed by Trane International Inc., Davidson, NC (US)
Filed on Mar. 9, 2023, as Appl. No. 18/181,292.
Application 18/181,292 is a continuation of application No. 16/926,403, filed on Jul. 10, 2020, granted, now 11,624,529.
Prior Publication US 2023/0213240 A1, Jul. 6, 2023
Int. Cl. F24H 9/20 (2022.01); F24D 19/10 (2006.01); F23D 14/02 (2006.01); F23J 15/06 (2006.01); F23N 3/00 (2006.01); F23N 3/08 (2006.01); F23N 5/24 (2006.01); F24D 5/02 (2006.01)
CPC F24H 9/2085 (2013.01) [F24D 19/1084 (2013.01); F23D 14/02 (2013.01); F23J 15/06 (2013.01); F23N 3/002 (2013.01); F23N 3/082 (2013.01); F23N 5/242 (2013.01); F23N 2231/26 (2020.01); F23N 2233/08 (2020.01); F23N 2233/10 (2020.01); F23N 2241/02 (2020.01); F24D 5/02 (2013.01); F24D 2220/06 (2013.01); Y02B 30/70 (2013.01); Y02E 20/30 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A heating, ventilation, and air conditioning (HVAC) system comprising:
a heat exchanger including an external surface;
a circulation fan configured to circulate air across the external surface of the heat exchanger to produce a conditioned airflow; and
a controller configured to:
estimate an airflow rate of the conditioned airflow based on two or more parameters of a motor of the circulation fan, wherein at least one of the two or more parameters is indicative of a speed of the motor and at least another of the two or more parameters is indicative of a torque of the motor,
operate the motor at a speed and a torque that corresponds to a target temperature differential of the conditioned airflow,
increase one of either the speed or torque of the motor in response to the two or more parameters indicating that the airflow rate is less than an airflow rate corresponding to the target temperature differential, and
adjust operation of at least one of the following components: the circulation fan and a burner assembly of a furnace, and
wherein adjusting the operation of the at least one component is in response to an indication by a combination of the speed and torque parameters that the estimated airflow rate is less than a minimum airflow rate.