Dual thermochromic liquid crystal temperature sensing for refrigerant charge indication
US7552596B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 2004 |
| Grant date | Jun 30, 2009 |
| Priority date | — |
| Expiry date | Sep 25, 2026 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25D2400/36
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
The sufficiency of refrigerant charge in an air conditioning system is determined by a comparison of two sensed temperatures in the system, one being the liquid line temperature and the other being either the outdoor temperature or the condenser coil temperature. In one embodiment the two sensed temperatures are displayed on respective thermochromic strips which are so calibrated and juxtaposed as to provide a visual indication, by the relative positions of the two displayed sensed temperatures, as to whether the refrigerant charge is adequate. In another embodiment, the sensed liquid line temperature is displayed by way of a plurality of LEDs and the other temperature is displayed by way of a marker on a temperature scale. If the two displayed temperatures are aligned, then the refrigerant charge is optimized, and if they are not aligned, the system is undercharged or overcharged.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.