Desa VRL24NR, VRL24PR, VRL30NR, VRL30PR, CSG3924NR,CSG3924PR Owner's Operating & Installation Manual

Also see for CSG3924NR: OWNER'S OPERATION AND INSTALLATION MANUAL OWNER'S OPERATION AND INSTALLATION MANUAL OWNER'S OPERATION AND INSTALLATION MANUAL OWNER'S OPERATION AND INSTALLATION MANUAL Owner's manual

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Desa VRL24NR, VRL24PR, VRL30NR, VRL30PR, CSG3924NR,CSG3924PR Owner's Operating & Installation Manual Manual pdf 7 page image

www.desatech.com110021-01H 7AIR FOR COMBUSTIONAND VENTILATIONContinued40,00031,50071,500Unusually 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 (6x10-11 kg per pa-sec-m 2 ) 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 the three criteriaabove, you must provide additional fresh air.See Ventilation Air From Outdoors, page 8.If your home does not meet all of the threecriteria above, proceed to DeterminingFresh-Air Flow For Heater Location.Confined Space 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 20 ft. (length) x 16 ft.(width) x 8 ft. (ceiling height) = 2,560 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: 2,560 cu. ft. (volume of space) x 20 =51,200 (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.Example:Gas water heater __________ Btu/HrVent-free fireplace + __________ Btu/HrTotal = __________ Btu/Hr4. Compare the maximum Btu/Hr the space cansupport with the actual amount of Btu/Hr used._________ Btu/Hr (maximum the space can support)_________ Btu/Hr (actual amount of Btu/Hr used)Example: 51,200 Btu/Hr (maximum the spacecan support)79,000 Btu/Hr (actual amount ofBtu/Hr used)The space in the example is a confined space becausethe actual Btu/Hr used is more than the maximumBtu/Hr the space can support. You must provide ad-ditional fresh air. Your options are as follows:A. Rework worksheet, adding the space of an adjoin-ing room. If the extra space provides an unconfinedspace, remove door to adjoining room or addventilation grills between rooms. See VentilationAir From Inside Building, page 8.B. Vent room directly to the outdoors. See Ventila-tion Air From Outdoors, page 8.C. Install a lower Btu/Hr fireplace, if lower Btu/Hrsize makes room unconfined.