3916991

Information

• Patent Grant
• 3916991

• References
• Source

• Patent Number

  3,916,991

• Date Filed

  Not available

• Date Issued

  Tuesday, November 4, 1975
  49 years ago

• CPC

  • F28D21/0007 - Water heaters
  • F24D12/02 - having more than one heat source
  • F24H6/00 - Combined water and air heaters
  • F24D2200/04 - Gas or oil fired boiler
  • F24D2200/18 - Flue gas recuperation
  • Y02B10/70 - Hybrid systems
  • Y02B30/14 - Central heating systems having more than one heat source
  • Y10S165/441 - Helical
  • Y10S165/901 - Heat savers
  • Y10S165/909 - Regeneration

• US Classifications

  • 165 - Heat exchange
  • 122 - Liquid heaters and vaporizers
  • 126 - Stoves and furnaces