Desa LSL18NT Safety Information And Installation Manual

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Desa LSL18NT Safety Information And Installation Manual Manual pdf 6 page image

www.desatech.com 116292-01A6AIR FOR COMBUSTIONAND VENTILATIONContinuedDETERMINING FRESH-AIR FLOWFOR HEATER LOCATIONDetermining if You Have a Confined orUnconfined SpaceUse this work sheet to determine if you have a con-fined or unconfined space.Space: Includes the room in which you will installheater 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. (6.1 m) (length) x 16ft. (4.88 m)(width) x 8 ft. (2.44 m) (ceiling height)= 2560 cu. ft. (72.49 m3) (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 = (MaximumBtu/Hr the space can support)Example: 2560 cu. ft. (72.49 m3 ) (volume ofspace) x 20 = 51,200 (maximum Btu/Hr the spacecan support)3. Add the Btu/Hr of all fuel burning appliances inthe space.Vent-free heater ___________ 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 heater + __________ Btu/HrTotal = __________ Btu/Hr40,00018,00058,0004. 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)58,000 Btu/Hr (actual amount ofBtu/Hr used)The space in the above example is a confined spacebecause the actual Btu/Hr used is more than the maxi-mum Btu/Hr the space can support. You must provideadditional 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 7.B. Vent room directly to the outdoors. See Ventila-tion Air From Outdoors, page 7.C. Install a lower Btu/Hr heater, if lower Btu/Hr sizemakes room unconfined.If the actual Btu/Hr used is less than the maximumBtu/Hr the space can support, the space is an uncon-fined space. You will need no additional fresh airventilation.WARNING: If the area inwhich the heater may be oper-ated is smaller than that definedas an unconfined space or if thebuilding is of unusually tightconstruction, provide adequatecombustion and ventilation airby one of the methods describedin the National Fuel Gas Code,ANSI Z223.1/NFPA 54 Section 5.3or applicable local codes.