Patent · US Expired

Adaptive defrost system

US4884414A · kind A · utility

31Cited by
20References
36Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 26, 1987
Grant dateDec 5, 1989
Priority date
Expiry dateAug 26, 2007

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF25D2700/14
  • WIPO fieldThermal processes and apparatus
  • WIPO sectorMechanical engineering

Abstract

A defrost system adapted for use with refrigeration or heat pump systems wherein an evaporator coil defrost cycle is adaptively modified in response to changing environmental conditions. Under normal conditions, a defrost operation is effected at the end of a period of frost accumulation. The period of frost accumulation is adjusted in accordance with deviation from a desired defrost time of the time required to raise the temperature of the coil from a first predetermined temperature to a second predetermined temperature. If a predetermined maximum defrost period is exceeded, the frost accumulation period is set to a predetermined value. During the frost accumulation period, the differential between the temperature of the coil and ambient temperature is determined, and the frost accumulation period terminated and a defrost operation initiated if temperature differential exceeds a target differential.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.