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. 28, 1989
Filed:
Jul. 17, 1987
Applicant:
Inventor:
Lee A White, Keller, TX (US);
Assignee:
Ranco Incorporated, Dublin, OH (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F25D / ;
U.S. Cl.
CPC ...
62155 ; 62156 ; 62234 ; 165 17 ; 165 29 ;
Abstract
A demand defrost controller for a heat pump. The controller compares the temperature of an outdoor heat exchange coil with an enable temperature. A timer is activated when the coil temperature is less than the enable temperature. When the timer senses the compressor has run for a predetermined time the controller checks outdoor and coil temperatures to determine if a defrost cycle of the heat pump should be conducted. A defrost cycle is achieved by reversing refrigerant flow in the heat pump system for a predetermined period or until the outdoor heat exchange coil has been heated to a termination temperature.