04679545 is referenced by 11 patents and cites 7 patents.

A heat exchanger unit for use with spas or hot tubs. The unit is constructed to be installed in a side wall of a portable spa or hot tub. The unit has an exposed front plate or panel, and the unit is constructed so as to limit the temperature to which this panel can reach. The heater unit includes a finned tube construction and a blower with a double impeller. Flue gases enter into one end of the blower unit, and fresh air enters this end and also the opposite end so that the flue gases mix with fresh air. The discharge from the blower is through louvers in the front panel. The temperature of the front panel does not rise above a limiting value. The heat exchanger unit is automatically controlled and controls the temperature of the water in the spa or hot tub. A control is provided including a pitot tube positioned in the blower outlet whereby to shut down the system in the event of absence or failure of flow of gases which could allow the temperature to rise above the limiting value.

Title
Gas-fired outdoor spa and hot tub heater
Application Number
778436
Publication Number
4679545
Application Date
June 16, 1986
Publication Date
July 14, 1987
Inventor
Adrian V Cavestany
Moorpark
CA, US
Agent
Evanns & Walsh
Assignee
Raypak
CA, US
IPC
F24H 1/00
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