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:
Apr. 12, 1988
Filed:
Aug. 25, 1987
Andrew S Robertson, Lafayette, CA (US);
Other;
Abstract
A heating system comprising a firebox defining a combustion chamber that is substantially sealed from the atmosphere. The system includes a flue for conducting combustion gases from the combustion chamber. A first duct surrounds the flue and defines an inner passageway with respect thereto. A second duct surrounds the first duct and defines an outer passageway. An inlet means is provided for introducing ambient air into the outer passageway. The air in the outer passageway is drawn through the inner passageway by a negative pressure in the combustion chamber. The ambient air in the inner and outer passageways is heated by heat transmitted from the flue. This heated ambient air is then introduced in the combustion chamber to improve the efficiency of combustion.