Blocked fan detection system for heat pump
US5440890A · kind A · utility
96Cited by
15References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1993 |
| Grant date | Aug 15, 1995 |
| Priority date | — |
| Expiry date | Dec 10, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B30/70
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A blocked fan or obstructed airflow condition is detected by measuring the difference between outdoor air temperature and outdoor exchanger coil temperature. If a very high difference is detected, or if no decrease in the difference is achieved after termination of the defrost cycle, and if either of these conditions persists over a plurality of defrost cycles, then the blocked condition is declared. The diagnostic system can be integrated in an existing demand defrost cycle and is capable of detecting blocked conditions attributable to foreign matter such as leaves, paper and debris which cannot be cleared by defrosting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.