F24D 9/00
Central heating systems employing combinations of heat transfer fluids covered by two
Official title: Central heating systems employing combinations of heat transfer fluids covered by two or more of groups F24D1/00 - F24D7/00 (district heating systems F24D10/00; central heating systems using heat accumulated in storage masses F24D11/00)
F24D9/00 (Central heating systems employing combinations of heat transfer fluids covered by two) appears on 25 US grants and 21 published applications in this corpus.
Search patents in F24D- Granted patents
- 25
- Published applications
- 21
- Assignees
- 17
- Inventors
- 53
- Latest grant
- 4 Mar 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 2 | 0 |
| 1978 | 1 | 0 |
| 1979 | 2 | 0 |
| 1980 | 1 | 0 |
| 1981 | 2 | 0 |
| 1982 | 0 | 0 |
| 1983 | 2 | 0 |
| 1984 | 0 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 1 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 1 | 0 |
| 1991 | 1 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 0 | 0 |
| 2003 | 1 | 1 |
| 2004 | 1 | 2 |
| 2005 | 0 | 1 |
| 2006 | 0 | 0 |
| 2007 | 0 | 1 |
| 2008 | 1 | 1 |
| 2009 | 1 | 1 |
| 2010 | 0 | 0 |
| 2011 | 0 | 1 |
| 2012 | 0 | 0 |
| 2013 | 0 | 1 |
| 2014 | 0 | 0 |
| 2015 | 1 | 1 |
| 2016 | 0 | 1 |
| 2017 | 1 | 0 |
| 2018 | 1 | 2 |
| 2019 | 0 | 0 |
| 2020 | 0 | 1 |
| 2021 | 2 | 0 |
| 2022 | 1 | 3 |
| 2023 | 0 | 0 |
| 2024 | 0 | 1 |
| 2025 | 1 | 1 |
| 2026 | 0 | 2 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Air heating apparatus4 Mar 2025US 12,241,641 B2Kyungdong Navien Co., Ltd.
- Methods and systems for thermal energy storage and their use in buildings applications25 Oct 2022US 11,480,395 B2Alliance for Sustainable Energy, LLC
- Heating system, kit and method of using16 Nov 2021US 11,175,051 B2
- Heat exchange system and method of controlling the alternation and redundancy between heat exchangers therein23 Mar 2021US 10,955,145 B2Maxi-Therme Inc.
- Combined space conditioning or heating and water heating system3 Jul 2018US 10,012,396 B2Intellihot, Inc.
- Systems and methods for integrating a water heating unit and a heat pump1 Oct 2026US 2026/0298484 A1
- Systems and methods for integrating a water heating unit and a heat pump1 Oct 2026US 2026/0298485 A1
- Energy and hydrometric control of horticultural greenhouses20 Nov 2025US 2025/0351782 A1Les Industries Harnois Inc.
- Automatically switching a combi radiator25 Apr 2024US 2024/0133562 A1Sagemcom Energy & Telecom SAS
- Air heating apparatus9 Jun 2022US 2022/0178553 A1Kyungdong Navien Co., Ltd.
Most cited
By later US patents
- Hot water heating and defrost in a heat pump circuit49US 4,646,537 AAmerican Standard Inc. · 1987
- Unified hot water and forced air heating system45US 4,178,907 A1979
- Use of synthetic hydrocarbon oils as heat transfer fluids16US 4,239,638 AUniroyal, Inc. · 1980
- Arrangement for heating rooms uniformly trough the equalization of the temperature distribution between the ceiling and the floor regions15US 4,950,871 A1990
- Air circulation and humidification system for stoves9US 4,256,081 A1981