F24F 3/052
Multiple duct systems
Official title: Multiple duct systems, e.g. systems in which hot and cold air are supplied by separate circuits from the central station to mixing chambers in the spaces to be conditioned
F24F3/052 (Multiple duct systems) appears on 89 US grants and 74 published applications in this corpus.
Search patents in F24F- Granted patents
- 89
- Published applications
- 74
- Assignees
- 44
- Inventors
- 149
- Latest grant
- 15 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 7 | 0 |
| 1977 | 8 | 0 |
| 1978 | 4 | 0 |
| 1979 | 3 | 0 |
| 1980 | 1 | 0 |
| 1981 | 2 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 2 | 0 |
| 1986 | 0 | 0 |
| 1987 | 3 | 0 |
| 1988 | 0 | 0 |
| 1989 | 2 | 0 |
| 1990 | 3 | 0 |
| 1991 | 0 | 0 |
| 1992 | 3 | 0 |
| 1993 | 0 | 0 |
| 1994 | 2 | 0 |
| 1995 | 1 | 0 |
| 1996 | 1 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 1 | 0 |
| 2001 | 1 | 0 |
| 2002 | 0 | 0 |
| 2003 | 0 | 1 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 1 | 1 |
| 2007 | 0 | 0 |
| 2008 | 1 | 1 |
| 2009 | 0 | 1 |
| 2010 | 0 | 0 |
| 2011 | 0 | 2 |
| 2012 | 0 | 3 |
| 2013 | 0 | 0 |
| 2014 | 0 | 1 |
| 2015 | 3 | 3 |
| 2016 | 2 | 1 |
| 2017 | 3 | 4 |
| 2018 | 0 | 0 |
| 2019 | 2 | 7 |
| 2020 | 4 | 23 |
| 2021 | 6 | 10 |
| 2022 | 5 | 4 |
| 2023 | 6 | 4 |
| 2024 | 5 | 6 |
| 2025 | 4 | 2 |
| 2026 | 3 | 0 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- HVAC system using reheat from alternative heat source15 Sep 2026US 12,736,236 B2Tyco Fire & Security GmbH
- Air-mixing plenum and method of mixing flows of air therewith24 Feb 2026US 12,560,340 B2Ingénia Technologies Inc.
- Systems and methods for optimizing control of an air handling unit (AHU) to minimize electrical and thermal energy consumption of the ahu13 Jan 2026US 12,523,384 B2Schneider Electric Industries SAS
- Linearization of airflow through zone dampers of an HVAC system16 Sep 2025US 12,416,426 B2Rheem Manufacturing Company
- Air-conditioning system8 Jul 2025US 12,352,463 B2Fh Alliance Inc.
- Air-conditioning system6 Nov 2025US 2025/0341338 A1Fh Alliance Inc.
- Hvac system using reheat from alternative heat source29 May 2025US 2025/0172303 A1Tyco Fire & Security GmbH
- Systems and methods for reheat control of an hvac system11 Jul 2024US 2024/0230177 A9Johnson Controls Tyco IP Holdings LLP
- Air-mixing plenum and method of mixing flows of air therewith23 May 2024US 2024/0167702 A1Ingénia Technologies Inc.
- Hvac system using reheat from alternative heat source23 May 2024US 2024/0167703 A1Johnson Controls Tyco IP Holdings LLP
Most cited
By later US patents
- Personal comfort conditioner136US 4,905,475 A1990
- Energy conservation air conditioning system69US 3,979,922 AHoneywell Inc. · 1976
- Air-conditioning system and operation method thereof60US 5,103,896 AKabushiki Kaisha Toshiba · 1992
- Method and apparatus for controlling air-conditioning systems51US 4,136,732 ARanco Incorporated · 1979
- Zone air-conditioning control system for motor vehicle compartment49US 4,537,245 ANippondenso Co., Ltd. · 1985