F25B 2700/04
Refrigerant level
F25B2700/04 (Refrigerant level) appears on 328 US grants and 349 published applications in this corpus.
Search patents in F25B- Granted patents
- 328
- Published applications
- 349
- Assignees
- 160
- Inventors
- 749
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1977 | 2 | 0 |
| 1978 | 1 | 0 |
| 1979 | 0 | 0 |
| 1980 | 1 | 0 |
| 1981 | 1 | 0 |
| 1982 | 2 | 0 |
| 1983 | 0 | 0 |
| 1984 | 2 | 0 |
| 1985 | 2 | 0 |
| 1986 | 5 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 2 | 0 |
| 1990 | 1 | 0 |
| 1991 | 3 | 0 |
| 1992 | 5 | 0 |
| 1993 | 3 | 0 |
| 1994 | 0 | 0 |
| 1995 | 7 | 0 |
| 1996 | 4 | 0 |
| 1997 | 2 | 0 |
| 1998 | 7 | 0 |
| 1999 | 4 | 0 |
| 2000 | 7 | 0 |
| 2001 | 4 | 1 |
| 2002 | 3 | 4 |
| 2003 | 5 | 2 |
| 2004 | 2 | 6 |
| 2005 | 8 | 11 |
| 2006 | 7 | 19 |
| 2007 | 4 | 6 |
| 2008 | 8 | 12 |
| 2009 | 10 | 16 |
| 2010 | 8 | 13 |
| 2011 | 9 | 14 |
| 2012 | 6 | 13 |
| 2013 | 8 | 6 |
| 2014 | 6 | 11 |
| 2015 | 9 | 8 |
| 2016 | 13 | 14 |
| 2017 | 17 | 22 |
| 2018 | 16 | 18 |
| 2019 | 12 | 20 |
| 2020 | 17 | 29 |
| 2021 | 16 | 17 |
| 2022 | 19 | 23 |
| 2023 | 13 | 17 |
| 2024 | 19 | 17 |
| 2025 | 22 | 23 |
| 2026 | 6 | 7 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Autocascade system with superheat control6 Oct 2026US 12,753,960 B2Trane International Inc.
- Liquid level control of expansion valves in climate control systems23 Jun 2026US 12,663,190 B2Trane International Inc.
- CO2 refrigeration system with multiple receivers16 Jun 2026US 12,656,031 B2Hill Phoenix, Inc.
- Lubricant recovery system for heat exchange system and heat exchange system31 Mar 2026US 12,590,741 B2Carrier Corporation
- Method of evaluating refrigerant charge within a refrigeration circuit10 Feb 2026US 12,546,520 B2Carrier Corporation
- Liquid level control of expansion valves in climate control systems24 Sep 2026US 2026/0287231 A1Trane International Inc.
- Uninterruptible power supply for hvac&r system13 Aug 2026US 2026/0238036 A1Tyco Fire & Security GmbH
- Batch oil return system and method6 Aug 2026US 2026/0227103 A1John Bean Technologies Corporation
- Continuous refrigerant monitoring for pumped two-phase cooling system2 Jul 2026US 2026/0185757 A1Vertiv Corporation
- Refrigerant supply apparatus18 Jun 2026US 2026/0168713 A1Samsung SDI.Co., Ltd.
Most cited
By later US patents
- Method of determining refrigerant charge level in a space temperature conditioning system138US 6,571,566 B1Lennox Manufacturing Inc. · 2003
- Overcharge-undercharge diagnostic system for air conditioner controller129US 5,381,669 ACopeland Corporation · 1995
- Refrigerant level control in a refrigeration system98US 5,655,379 AGeneral Electric Company · 1997
- Solid state clutch cycler with charge protection97US 4,463,576 AGeneral Motors Corporation · 1984
- Refrigerant flow rate control based on liquid level in simple vapor compression refrigeration cycles97US 5,435,145 AGeneral Electric Company · 1995