F28D 21/0007
Water heaters
Official title: {Water heaters}
F28D21/0007 (Water heaters) appears on 193 US grants and 153 published applications in this corpus.
Search patents in F28D- Granted patents
- 193
- Published applications
- 153
- Assignees
- 76
- Inventors
- 326
- Latest grant
- 19 May 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 4 | 0 |
| 1977 | 9 | 0 |
| 1978 | 4 | 0 |
| 1979 | 7 | 0 |
| 1980 | 4 | 0 |
| 1981 | 5 | 0 |
| 1982 | 7 | 0 |
| 1983 | 11 | 0 |
| 1984 | 7 | 0 |
| 1985 | 4 | 0 |
| 1986 | 3 | 0 |
| 1987 | 5 | 0 |
| 1988 | 0 | 0 |
| 1989 | 1 | 0 |
| 1990 | 1 | 0 |
| 1991 | 1 | 0 |
| 1992 | 1 | 0 |
| 1993 | 0 | 0 |
| 1994 | 1 | 0 |
| 1995 | 0 | 0 |
| 1996 | 1 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 2 | 0 |
| 2002 | 1 | 1 |
| 2003 | 1 | 2 |
| 2004 | 1 | 3 |
| 2005 | 0 | 2 |
| 2006 | 1 | 2 |
| 2007 | 1 | 2 |
| 2008 | 4 | 3 |
| 2009 | 0 | 4 |
| 2010 | 2 | 2 |
| 2011 | 1 | 2 |
| 2012 | 1 | 2 |
| 2013 | 3 | 5 |
| 2014 | 0 | 1 |
| 2015 | 0 | 8 |
| 2016 | 1 | 10 |
| 2017 | 0 | 16 |
| 2018 | 11 | 24 |
| 2019 | 21 | 16 |
| 2020 | 10 | 14 |
| 2021 | 15 | 9 |
| 2022 | 14 | 14 |
| 2023 | 12 | 6 |
| 2024 | 6 | 2 |
| 2025 | 7 | 2 |
| 2026 | 2 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Heat exchanger baffles and methods for manufacturing the same19 May 2026US 12,631,409 B2Bradford White Corporation
- Heat exchanger for heating devices, and tube-assembly module for a heat exchanger10 Feb 2026US 12,546,510 B2Clada S.R.L.
- Flue gas energy recovery system and method25 Nov 2025US 12,480,720 B2Carbon Cap Inc.
- Condensation heat exchanger25 Nov 2025US 12,480,724 B2Sermeta
- Compact fluid heating system with high bulk heat flux using elevated heat exchanger pressure drop1 Jul 2025US 12,345,445 B2Fulton Group N.A., Inc.
- Outdoor energy-storage device18 Jun 2026US 2026/0168684 A1Envola GmbH
- Heat exchanger unit4 Sep 2025US 2025/0277602 A1Kyungdong Navien Co., Ltd.
- Water heater15 May 2025US 2025/0155162 A1Kyungdong Navien Co., Ltd.
- Heat exchange fin and heat exchange device18 Jul 2024US 2024/0240878 A1
- Compact fluid heating system with high bulk heat flux using elevated heat exchanger pressure drop25 Apr 2024US 2024/0133586 A1Fulton Group N.A., Inc.
Most cited
By later US patents
- Economizer with soot blower59US 4,407,237 AApplied Engineering Co. · 1983
- Process for recovering heat from stack or flue gas45US 4,340,572 AWoodside Construction, Inc. · 1982
- Heat recovery apparatus and an improved heat recovery method40US 5,347,958 A1994
- Waste heat recovery system and method37US 4,185,685 A1980
- Fireplace heating system31US 4,143,816 A1979