![Air Filter](/images/new-backgrounds/35668/3566821x1.webp)
Air Filter
An air filter is supplied standard with the heater. This filter is shipped loose for field installation. Refer to the Air Filter Kit Installation Instructions (Part No. 241338) for details.
Fig. 8: Air Filter Box
Direct Vent
If outside air is drawn through the intake pipe directly to the unit for combustion:
1.Install combustion air direct vent in accordance with Fig. 27 (horizontal) or Fig. 28 (vertical) of this manual (pages 28 and 29, respectively).
2.Provide adequate ventilation of the space occu- pied by the heater( s) by an opening (s) for ventilation air at the highest practical point com- municating with the outdoors. The total
3.In cold climates, and to mitigate potential freeze- up, Raypak highly recommends the installation of a motorized sealed damper to prevent the circula- tion of cold air through the heater during the
TruSeal™ Combustion Air
In addition to the 3 previous steps, combustion air may be ducted directly to the heater by using PVC, CPVC
or sealed
All ducting must be
CAUTION: Use TruSeal combustion air if damaging airborne contaminants are or may be present in the heater area. See the Appendix of this manual regarding air contamination.
Conventional Combustion Air Supply
U.S. Installations
All Air from Inside the Building
The confined space shall be provided with TWO per- manent openings communicating directly with an additional room(s) of sufficient volume so that the com- bined volume of all spaces meets the criteria for a room large in comparison (NFGC). The total input of all gas utilization equipment installed in the combined space shall be considered in making this determina- tion. Each opening shall have a minimum free area of 1 in.2 per 1,000 BTUH (2,225 mm2 per kW) of the total input rating of all gas utilization equipment in the con- fined space, but not less than 100 in.2 (645 cm2). One opening shall commence within 12 in. (305 mm) of the top, and one opening shall commence within 12 in. (305 mm) of the bottom of the enclosure. The mini- mum dimension of air openings shall be not less than 3 in. (76 mm) in any direction.
All Air from Outdoors
The confined space shall communicate with the out- doors in accordance with one of the methods below. The minimum dimension of air openings shall not be less than 3 in. (76 mm) in any direction. Where ducts are used, they shall be of the same
1.Two permanent openings, one commencing within 12 in. (305 mm) of the top, and one com- mencing within 12 in. (305 mm) of the bottom of
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