107032-01EFor more information, visit www.desatech.comFor more information, visit www.desatech.com773. Add the Btu/Hr of all fuel burning appliances in 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 com-bustion air from the outdoors and vents to the outdoors.Example:Gas water heater _____________ Btu/HrVent-free fireplace + _____________ 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: 35,840 Btu/Hr (maximum the space can support)40,000 Btu/Hr (actual amount of Btu/Hr used)The space in the above example is a confined space because the actual Btu/Hr used is more than the maximum Btu/Hr the space can support. You mustprovide additional fresh air. Your options are as follows:A. Rework worksheet, adding the space of an adjoining room. If theextra space provides an unconfined space, remove door to adjoiningroom or add ventilation grills between rooms. See Ventilation Air FromInside Building.B. Vent room directly to the outdoors. See Ventilation Air From Out-doors, page 8.C. Install a lower Btu/Hr fireplace, if lower Btu/Hr size makes roomunconfined.If the actual Btu/Hr used is less than the maximum Btu/Hr the space can support,the space is an unconfined space. You will need no additional fresh air ventilation.AIR FOR COMBUSTION ANDVENTILATIONContinuedVENTILATION AIRVentilation Air From Inside BuildingThis fresh air would come from an adjoining unconfined space.When ventilating to an adjoining unconfined space, you mustprovide two permanent openings: one within 12" of the ceiling andone within 12" of the floor on the wall connecting the two spaces(see options 1 and 2, Figure 5). You can also remove door intoadjoining room (see option 3, Figure 5). Follow the National FuelGas Code, ANSI Z223.1/NFPA 54, Section 5.3, Air for Combustionand Ventilation for required size of ventilation grills or ducts.Figure 5 - Ventilation Air from Inside BuildingAIR FOR COMBUSTION AND VENTILATIONDetermining Fresh-Air Flow for Fireplace Location (Cont.)Ventilation Air30,00010,00040,000WARNING: If the area in which the fireplace maybe operated is smaller than that defined as an uncon-fined space or if the building is of unusually tightconstruction, provide adequate combustion and ven-tilation air by one of the methods described in theNational Fuel Gas Code, ANSI Z223.1/NFPA 54 Sec-tion 5.3 or applicable local codes.OrRemoveDoor intoAdjoiningRoom,Option 3Ventilation GrillsInto Adjoining Room,Option 212"12"VentilationGrillsinto AdjoiningRoom,Option 1