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Directions-In order to determine the makeup air,Table 501.4.1 must be filled out(see below). For most new installations,column <br /> A will be appropriate,however,if atmospherically vented appliances or solid fuel appliances are installed,use the appropriate <br /> column.For existing dwellings,see MC 501.4.3. Please note,+f the makeup air quantity is negative,no additional makeup air will <br /> be required for ventilation,if the value is positive refer to Table 501.3.2 and size the opening. Transfer the cfm,size of opening and <br /> type(round,rectangular,flex or rigid)to the last line of section D. The make-up air supply must be installed per IMC 501.4.2.3. <br /> Table 501.4.1 <br /> PROCEDURE TO DETERMINE MAKEUP AIR QUANITY FOR EXHAUST EQUIPMENT IN DWELLINGS <br /> (Additional combustion air will be required for combustion appliances,see KAIR method for calculations) <br /> One or multiple power One or multiple fan- One atmospherically vent Multiple atmospherically <br /> vent or direct vent assisted appliances and gas or oil appliance or vented gas or oil <br /> appliances or no power vent or direct vent one solid fuel appliance appliances or solid fuel <br /> combustion appliances appliances appliances <br /> Column C Column D <br /> Column A Column B <br /> 1.Use the appropriate column to <br /> estimate house infiltration 0.15 0.09 0.06 0.03 <br /> a)pressure factor <br /> (cfm/sf) <br /> b)conditioned floor area(sf)(including 4664 <br /> unfinished basements) <br /> Estimated House Infiltration(cFm):[1a 279 <br /> x 1b] <br /> 2.Exhaust Capacity <br /> a)continuous exhaust-only ventilation Balanced <br /> system(cfm);(not applicable to <br /> balanced ventilation systems such as <br /> HRV) <br /> b)clothes dryer(cfm) 135 135 135 135 <br /> c)80%of largest exhaust rating(cfm); 480 <br /> Kitchen hood typically <br /> (not applicable if recirculating system <br /> or If powered makeup air is electrically <br /> interlocked and match to exhaust) <br /> d)80%of next largest exhaust rating <br /> (cfm); bath fan typically Not 64 <br /> (not applicable if recirculating system <br /> or if powered makeup air is electrically Applicable <br /> interlocked and matched to exhaust) <br /> Total Exhaust Capacity(cfm); <br /> [2a+2b+2c+2d] 679 <br /> 3.Makeup Air Quantity(cfm) <br /> a)total exhaust capacity(from above) 679 <br /> b)estimated house infiltration(from 279 <br /> above) <br /> Makeup Air Quantity(dm); <br /> [3a—3b] 400 <br /> (if value Is negative,no makeup air is <br /> needed) <br /> 4.For makeup Mr Opening Sizing, <br /> refer to Table 5014.2 Powered/Heated Make up air <br /> A. Use this column if there are other than fan-assisted or atmospherically vented gas or oil appliance or if there are no combustion appliances.(Power vent and <br /> direct vent appliances may be used.) <br /> B. Use this column if there is one fan-assisted appliance per venting system.(Appliances other than atmospherically vented appliances may also be included.) <br /> C. Use this column if there is one atmospherically vented(other than fan-assisted)gas or oil appliance per venting system or one solid fuel appliance. <br /> D. Use this columna there are multiple atmospherically vented gas or oil appliances using a common vent or if there are atmospherically vented gas or oil <br /> appliances and solid fuel appliances. <br /> l:\Building\SafetyPolicieslnformation\Current\2016\VentMakupCombAirCals2016.docx Page 3 of 6 <br />