GAS-FIRED OUTDOOR SPA AND HOT TUB HEATER
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 from 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 ?nned 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
150 the opposite end so that the ?ue ases mix with fresh air. The discharge from the blower is through louvers in the front panel. The temperature of the front Panel d°es "0‘ rise ab°V° *1 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.