Design Dynamics VF-18N-BTB Owner's Operation And Installation Manual

Also see for VF-18N-BTB: OWNER'S OPERATION AND INSTALLATION MANUAL OWNER'S OPERATION AND INSTALLATION MANUAL

Design Dynamics VF-18N-BTB Owner's Operation And Installation Manual Manual pdf 5 page image

111826-01For more information, visit www.desatech.com5540,00033,00073,000Unusually tight construction is defi ned as constructionwhere:a. walls and ceilings exposed to the outside atmospherehave a continu ous water vapor retarder with a ratingof one perm (6 x 10-11 kg per pa-sec-m2 ) or less withopen ings gasketed or sealed andb. weather stripping has been added on openable win-dows and doors andc. caulking or sealants are applied to areas such asjoints around window and door frames, between soleplates and floors, between wall-ceiling joints, betweenwall panels, at pene tra tions for plumbing, electrical,and gas lines, and at other openings.If your home meets all of the three criteria above, youmust provide additional fresh air. See Ventilation AirFrom Outdoors, page 6.If your home does not meet all of the three criteria above,proceed to De ter min ing Fresh-Air Flow For Heater Lo-ca tion, below.Confi ned and Unconfined SpaceThe National Fuel Gas Code, ANSI Z223.1/NFPA 54 defi nes acon fi ned space as a space whose volume is less than 50 cubic feetper 1,000 Btu per hour (4.8 m 3 per kw) of the aggregate input ratingof all ap pli anc es in stalled in that space and an uncon fi ned space asa space whose vol ume is not less than 50 cubic feet per 1,000 Btuper hour (4.8 m 3 per kw) of the aggregate input rating of all appli-ances in stalled in that space. Rooms commu ni cat ing di rect ly withthe space in which the appli anc es are in stalled*, through openingsnot fur nished with doors, are con sid ered a part of the unconfinedspace.* Adjoining rooms are communicating only if there are doorlesspassageways or ven ti la tion grills between them.DETERMINING FRESH-AIR FLOW FORHEATER LOCATIONDetermining if You Have a Confined or UnconfinedSpaceUse this work sheet to determine if you have a confined or unconfinedspace.Space: Includes the room in which you will install heater plus any ad-joining rooms with doorless passageways or ventilation grills betweenthe rooms.1. Determine the volume of the space (length x width x height).Length x Width x Height = ____________cu. ft. (vol ume of space)Example: Space size 20 ft. (length) x 16 ft. (width) x 8 ft. (ceilingheight) = 2560 cu. ft. (vol ume of space)AIR FOR COMBUSTION ANDVENTILATIONContinuedWARNING: If the area in which the heater may beoperated is smaller than that defined as an unconfinedspace or if the building is of unusually tight construc-tion, provide ad e quate com bustion and venti lationair by one of the methods described in the NationalFuel Gas Code, ANSI Z223.1/NFPA 54 Section 5.3 orapplicable local codes.If additional ventilation to adjoining room is supplied with grills or open-ings, add the volume of these rooms to the total volume of the space.2. Multiply the space volume by 20 to determine the maximum Btu/Hrthe space can support.____________(volume of space) x 20 = (Maximum Btu/Hr the spacecan sup port)Example: 2560 cu. ft. (volume of space) x 20 = 51,200 (maxi mumBtu/Hr the space can support)3. Add the Btu/Hr of all fuel burning appli anc es in the space.Vent-free heater _____________ Btu/HrGas water heater* _____________ Btu/HrGas fur nace _____________ Btu/HrVented gas heater _____________ Btu/HrGas fire place logs _____________ Btu/HrOther gas appliances* + _____________ Btu/HrTotal = _____________ Btu/Hr* Do not include direct-vent gas appliances. Direct-vent draws com-bus tion air from the outdoors and vents to the outdoors.Example:Gas water heater _____________ Btu/HrVent-free heater + _____________ Btu/HrTotal = _____________ Btu/Hr4. Compare the maximum Btu/Hr the space can support with the actualamount of Btu/Hr used.____________________Btu/Hr (maximum the space can support)____________________Btu/Hr (actual amount of Btu/Hr used)Example: 51,200 Btu/Hr (max i mum the space can support)73,000 Btu/Hr (actual amount of Btu/Hr used)The space in the above example is a confi ned space because the actualBtu/Hr used is more than the maximum Btu/Hr the space can support. Youmust provide additional fresh air. Your op tions are as follows:A. Rework worksheet, adding the space of an adjoining room. If the extraspace provides an unconfined space, remove door to adjoining room oradd ven ti la tion grills between rooms. See Ven ti la tion Air From InsideBuilding, page 6.B. Vent room directly to the outdoors. See Ventilation Air From Outdoors,page 6.C. Install a lower Btu/Hr heater, if lower Btu/Hr size makes room uncon-fined.If the actual Btu/Hr used is less than the maximum Btu/Hr the space can sup-port, the space is an unconfined space. You will need no additional fresh airven ti la tion.AIR FOR COMBUSTION AND VENTILATIONProviding Adequate Ventilation (Cont.)Determining Fresh-Air Flow for Heater Location