Desa VDCFRNA Owner's Operation And Installation Manual

Contents

www.desatech.com113133-01B 7PROVIDING 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,column 2.AIR FOR COMBUSTIONAND VENTILATIONContinuedConfined 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 m 3 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 will installfireplace plus any adjoining rooms with doorless pas-sageways or ventilation grills between the rooms.1. Determine the volume of the space (length xwidth x height).Length x Width x Height =__________cu. ft.(volume of space)Example: Space size 16 ft. (length) x 14 ft.(width) x 8 ft. (ceiling height) = 1792 cu. ft.(volume of space)If additional ventilation to adjoining room issupplied with grills or openings, add the volumeof these rooms to the total volume of the space.2. Multiply the space volume by 20 to determinethe maximum Btu/Hr the space can support.__________ (volume of space) x 20 = (Maxi-mum Btu/Hr the space can support)Example: 1792 cu. ft. (volume of space) x 20 =35,840 (maximum Btu/Hr the space can support)3. Add the Btu/Hr of all fuel burning appliances inthe space.Vent-free fireplace ___________ Btu/HrGas water heater* ___________ Btu/HrGas furnace ___________ Btu/HrVented gas heater ___________ Btu/HrGas fireplace logs ___________ Btu/HrOther gas appliances* + ___________ Btu/HrTotal = ___________ Btu/Hr* Do not include direct-vent gas appliances. Di-rect-vent draws combustion air from the outdoorsand vents to the outdoors.