Hayward Universal-H 500K BTU 8″ Negative Pressure Indoor Vent Adapter

The heater must be installed such that the installation and service clearances from combustible materials shown in Table 4 are maintained. This heater may be installed on combustible floors. Do not install heater in a closet. Indoor installations and outdoor shelters (confined spaces) must be provided with adequate combustion and ventilation air vents to assure proper heater operation. These vents must be sized according to the requirements stated in paragraph A or B below (whichever applies to the installation). These vents must never be obstructed when heater is in operation. When air blowers are used in spa/hot tub installations and are located in proximity to the heater, caution must be observed to ensure sufficient combustion air is available to the heater for proper combustion. A separate blower air duct is recommended.