Design Dynamics VF-18N-PJD Owner's Operating & Installation Manual

Also see for VF-30P-PJD: OWNER'S OPERATION AND INSTALLATION MANUAL

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Design Dynamics VF-18N-PJD Owner's Operating & Installation Manual Manual pdf 7 page image

www.fmiproducts.com111826-04E 7AIR FOR COMBUSTION AND VENTILATIONContinued40,00033,00073,000Confined and Unconfined SpaceThe National Fuel Gas Code, ANSI Z223.1/NFPA 54 defines a confined space as a spacewhose volume is less than 50 cubic feet per1,000 Btu per hour (4.8 m3 per kw) of the ag-gregate input rating of all appliances installed inthat space and an unconfined space as a spacewhose volume is not less than 50 cubic feet per1,000 Btu per hour (4.8 m3 per kw) of the ag-gregate input rating of all appliances installed inthat space. Rooms communicating directly withthe space in which the appliances are installed*,through openings not furnished with doors, areconsidered a part of the unconfined space.* Adjoining rooms are communicating only ifthere are doorless passageways or ventilationgrills between them.DETERMINING FRESH-AIR FLOWFOR HEATER LOCATIONDetermining if You Have a Confined orUnconfined SpaceUse this work sheet to determine if you havea confined or unconfined space.Space: Includes the room in which you willinstall heater plus any adjoining rooms withdoorless passageways or ventilation grillsbetween the rooms.1. Determine the volume of the space (lengthx width 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 is sup-plied with grills or openings, add the volume ofthese 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) x20 = 51,200 (maximum Btu/Hr the space cansupport )3. Add the Btu/Hr of all fuel burning appliancesin the 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.Direct-vent draws combustion air from theoutdoors and vents to the outdoors.Example:Gas water heater _________ Btu/HrVent-free fireplace + _________ Btu/HrTotal = _________ Btu/Hr4. Compare the maximum Btu/Hr the spacecan support with the actual amount of Btu/Hr used._______ Btu/Hr (maximum the space can sup-port)________ Btu/Hr (actual amount of Btu/Hrused)Example: 51,200 Btu/Hr (maximum thespace can support)73,000 Btu/Hr (actual amount ofBtu/Hr used)The space in the above example is a confinedspace because the actual Btu/Hr used is morethan the maximum Btu/Hr the space can sup-port. You must provide additional fresh air. Youroptions are as follows:A. Rework worksheet, adding the space of anadjoining room. If the extra space providesan unconfined space, remove door to adjoin-ing room or add ventilation grills betweenrooms. See Ventilation Air From InsideBuilding, page 8.B. Vent room directly to the outdoors. SeeVentilation Air From Outdoors, page 8.C. Install a lower Btu/Hr fireplace, if lower Btu/Hr size makes room unconfined.If the actual Btu/Hr used is less than the maxi-mum Btu/Hr the space can support, the space isan unconfined space. You will need no additionalfresh air ventilation.WARNING: If the area inwhich the heater may be oper-ated does not meet the requiredvolume for indoor combustionair, combustion and ventilationair shall be provided by one ofthe methods described in theNational Fuel Gas Code, ANSIZ223.1/NFPA 54, the Internation-al Fuel Gas Code, or applicablelocal codes.