Air For Combustion; Air For Combustion -- Horizontal Through A Sidewall - Space-Ray FUSION Series Installation & Operation Instructions

B. INDIRECT VENTING
products of combustion and provide fresh air for efficient combustion. Where unvented heaters are used,
gravity or mechanical means shall be provided to supply and exhaust at least 4 CFM per 1,000 Btu/hr input
of installed heaters. Exhaust vents must be located at the highest point above and in the vicinity of the
heaters, and the inlet vents must be located below the level of the heaters. An exhaust hood (Part
#42924100) must be placed on the end of the last body section when used unvented and must be mounted
only in a downward position as shown.
15.0)

AIR FOR COMBUSTION

If indoor combustion air is to be supplied for a tightly enclosed area, one square inch of free area opening shall
be provided below the heater for each 1,000 Btu/hr of heater input. When outside air is used, the opening below
the heater shall be one square inch of free area for each 4,000 Btu/hr of heater input. In contaminated
atmospheres or high humidity areas, optional outside air for combustion is recommended. Adequate clearances
around the air inlet screen must be maintained at all times. In larger open areas of buildings, infiltration normally
is adequate to provide air for combustion.
15.1)

AIR FOR COMBUSTION -- HORIZONTAL THROUGH A SIDEWALL

Outside combustion air should be supplied directly to the heater when the building is subject to negative pressure,
or when contaminants or high humidity are present in the building air. These contaminants include paints,
solvents, corrosive vapors or any other foreign particles that may cause damage to the heater or result in poor
combustion.
Outside combustion air can be brought directly to the heater by a 4" diameter duct (field supplied) less than 20 ft.
long or equivalent. An approved vent cap and 4" flexible hose (supplied in accessory Kit #44129510) must be
connected to the duct as shown below. Connect the 4" flexible hose directly to the 4" starting collar (supplied with
heater). This is used to allow for expansion/contraction of tube heaters assembled in straight configurations.
Form 43343100
April 2022 A
(UNVENTED HEATERS) — This heater requires ventilation in the building to dilute the
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