Furnace controller and a furnace that controls a gas input rate to maintain a discharge air temperature

摘要

Provided herein are embodiments of a multistage gas furnace, a controller therefor and a computer-usable medium having non-transitory computer readable instructions stored thereon for execution by a processor to perform a method for operating a gas furnace. In one embodiment, the gas furnace includes: (1) a burner, (2) a circulation fan and (3) a furnace controller. The furnace controller having: (3A) an interface configured to receive heating calls and a blower control signal, the blower control signal corresponding to an operating speed of the circulation fan and (3B) a processor configured to respond to the heating calls and the blower control signal by setting and adjusting a gas input rate for the burner that is based on the blower control signal and that corresponds to a discharge air temperature determined by a dedicated discharge air sensor associated with the furnace.

主权项

1. A controller, comprising:
an interface configured to:
receive one or more heating calls;receive a blower control signal, said blower control signal indicating an operating speed of a circulation fan coupled to a multistage gas furnace; and a processor configured to:
determine, in response to receiving said heating calls, a discharge air temperature based on said blower control signal;determine and set a gas input rate for said multistage gas furnace according to outer loop control, the outer loop control using one or more lookup tables that relate the gas input rate to the discharge air temperature determined based on said blower control signal; anddetermine and set an adjustment of the gas input rate for said multistage gas furnace according to inner loop control, the inner loop control configured to use feedback from a discharge air sensor to maintain the determined discharge air temperature.