US Patent:
20130067943, Mar 21, 2013
Inventors:
Trane International Inc. - Piscataway NJ, US
John R. Edens - Kilgore TX, US
Alan D. Marble - Whitehouse TX, US
Kevin B. Mercer - Troup TX, US
Gary L. Sapp - Tyler TX, US
Kristin L. Schaefer - Tyler TX, US
Steven A. Tice - Flint TX, US
Assignee:
TRANE INTERNATIONAL INC. - Piscataway NJ
International Classification:
F25B 47/02
F25B 13/00
F25B 49/02
Abstract:
A system and a method are provided for returning oil in a heating, ventilation, and air conditioning (HVAC) system by determining when an ambient zone temperature is equal to or less than a temperature limit and reversing a direction of refrigerant flow of the HVAC system based on the length of time. Also, a system and a method are provided for monitoring the length of operation in a first and a second heating mode and for reversing a direction of refrigerant flow based on the length of time operation occurs in the first and second heating modes. A system and a method having a first compressor, a first heating mode, a second heating mode, a defrost mode, and a controller is disclosed. The controller selectively controls initiation of the defrost mode in response to an HVAC system operating in a heating mode of operation for a predetermined amount of time.
