6105566INFRARED NATURAL GAS HEATERFigure 3 - Ventilation Air from OutdoorsVentilation Air From OutdoorsProvide extra fresh air by using ventilationgrills or ducts. You must provide two per-manent openings: one within 12" of theceiling and one within 12" of the floor.Connect these items directly to the outdoorsor spaces open to the outdoors. These spacesinclude attics and crawl spaces. Follow theNational Fuel Gas Code NFPA 54/ANSZ223.1, Section 5.3, Air for Combustion andVentilation for required size of ventilationgrills or ducts.IMPORTANT: Do not provide openings forinlet or outlet air into attic if attic has athermostat-controlled power vent. Heated airentering the attic will activate the power vent.OutletAirVentilatedAtticOutletAirInletAirInlet Air VentilatedCrawl SpaceToCrawlSpaceTo AtticFRESH AIR FORCOMBUSTION ANDVENTILATIONContinuedOrRemoveDoor intoAdjoiningRoom,Option 3Ventilation GrillsInto Adjoining Room,Option 212"12"VentilationGrillsinto AdjoiningRoom,Option 1VENTILATION AIRVentilation Air From InsideBuildingThis fresh air would come from an adjoiningunconfined space. When ventilating to anadjoining unconfined space, you must pro-vide two permanent openings: one within12" of the ceiling and one within 12" of thefloor on the wall connecting the two spaces(see options 1 and 2, Figure 2). You can alsoremove door into adjoining room (see op-tion 3, Figure 2). Follow the National FuelGas Code NFPA 54/ANS Z223.1, Section5.3, Air for Combustion and Ventilation forrequired size of ventilation grills or ducts.Figure 2 - Ventilation Air from Inside BuildingWARNING: Rework work-sheet, adding the space of theadjoining unconfined space. Thecombined spaces must haveenough fresh air to supply allappliances in both spaces.