The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 1999
Filed:
Mar. 27, 1998
Kevin D Thompson, Indianapolis, IN (US);
Carrier Corporation, Farmington, CT (US);
Abstract
A combustion air regulating apparatus which is adapted for use with two stage induced draft furnaces and which allows such furnaces to be used with low cost AC inducer motors of the type having one or a small number of nominally fixed operating speeds. A flow restrictor assembly is disposed in fluidic series with the air intake and the exhaust vent to controllably restrict the flow of air through the burner box when the inducer motor operates at its low speed. A pressure sensing assembly is connected to sense a pressure approximately equal to that across the heat exchanger, and to control the flow resistance of the flow restrictor assembly to maintain a sufficient level of excess air when the furnace operates in its low stage. A solenoid valve responsive to the establishment of high stage furnace operation causes the flow restrictor assembly to establish and maintain its minimum flow resistance during operation in that stage.