www.desatech.com 111245-01C6AIR FOR COMBUSTIONAND VENTILATIONWARNING: This heater shallnot be installed in a confinedspace or unusually tight con-struction unless provisions areprovided for adequate combus-tion and ventilation air. Read thefollowing instructions to insureproper fresh air for this andother fuel-burning appliancesin your home.Today’s homes are built more energy efficientthan ever. New materials, increased insulation andnew construction methods help reduce heat lossin homes. Home owners weather strip and caulkaround windows and doors to keep the cold air outand the warm air in. During heating months, homeowners want their homes as airtight as possible.While it is good to make your home energy effi-cient, your home needs to breathe. Fresh air mustenter your home. All fuel-burning appliances needfresh air for proper combustion and ventilation.Exhaust fans, fireplaces, clothes dryers and fuelburning appliances draw air from the house tooperate. You must provide adequate fresh air forthese appliances. This will insure proper ventingof vented fuel-burning appliances.PROVIDING ADEQUATEvENTILATIONThe following are excerpts from National FuelGas Code, ANSI Z223.1/NFPA 54, Section 5.3,Air for Combustion and Ventilation.All spaces in homes fall into one of the three fol-lowing ventilation classifications:1. Unusually Tight Construction2. Unconfined Space3. Confined SpaceThe information on pages 6 through 8 will helpyou classify your space and provide adequateventilation.Unusually Tight ConstructionThe air that leaks around doors and windowsmay provide enough fresh air for combustion andventilation. However, in buildings of unusuallytight construction, you must provide additionalfresh air.Unusually tight construction is defined asconstruction where:a. walls and ceilings exposed to the out-side atmosphere have a continuouswater vapor retarder with a rating ofone perm (6 x 10-11 kg per pa-sec-m2) orless with openings gasketed or sealedandb. weather stripping has been added onopenable windows and doors andc. caulking or sealants are applied toareas such as joints around windowand door frames, between sole platesand floors, between wall-ceiling joints,between wall panels, at penetrationsfor plumbing, electrical and gas linesand at other openings.If your home meets all of these threecriteria, you must provide additionalfresh air. See Ventilation Air FromOutdoors, page 8.If your home does not meet all of the threecriteria above, proceed to DeterminingFresh-Air Flow For Fireplace Location.Confined and Unconfined SpaceThe National Fuel Gas Code, ANSI Z223.1/NFPA54 defines a confined space as a space whosevolume is less than 50 cubic feet per 1,000 Btuper hour (4.8 m3 per kw) of the aggregate inputrating of all appliances installed in that space andan unconfined space as a space whose volume isnot less than 50 cubic feet per 1,000 Btu per hour(4.8 m3 per kw) of the aggregate input rating ofall appliances installed in that space. Rooms com-municating directly with the space in which theappliances are installed*, through openings notfurnished with doors, are considered a part of theunconfined space.* Adjoining rooms are communicating only ifthere are doorless passageways or ventilation grillsbetween them.DETERMINING FRESH-AIR FLOWFOR FIREPLACE LOCATIONDetermining if You Have a Confined orUnconfined SpaceUse this work sheet to determine if you have aconfined or unconfined space.Space: Includes the room in which you willinstall fireplace plus any adjoining rooms withdoorless passageways or ventilation grills betweenthe rooms.