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Z�� <br /> •Directions-The Minnesota Fuel Gos Code method to caJculate to size of a reguired combustion oir openin�is called the Known Air <br /> Infiltration Rate Method. For nsw constrvttion,46 of step 4;s reQuirPd tn be ftlled ot�t. <br /> IFGC Appendix E,Worksheet E-i,1346.6012 <br /> Residential Combusiion Air Calculation MethOd <br /> (for Purnacn,Boilar,and/or Watl�Heater in the Same S a[8 <br /> Step 1:Complete vented combusdon appUance information. <br /> Fumace/Boiler. ����) 8��� <br /> Oraft Hood _Fan Assisted �ifEd VEnt Input: / <br /> orPowerVent <br /> WaterHeater: ��(,> g�/hr <br /> OrBft Hppd �Fan Assisted _,Direct Vent ��P�� � <br /> � or Power Vent <br /> Step 2:Gicutate the volume of the Combustion Applianoe Spate lCAS)[011t�iDing CAmbustion eppfiente5. • �� , � <br /> The CAS Indude5 21)Spates connated to one another by code compliant openings. CAS vollNi�E: <br /> �xWXH L W H pZIE� X. <br /> Step 3:Determine tir Changes per Hour(ACH)1 <br /> Oefault ACH values have been incorporated�r�to Table E-1 for us2 wtth MethOd 4b(KAIR MEthod). <br /> If the ear of construetlon or ACM is noi known,use mechod aa(Sesndard Method}. <br /> Step A:Determine Required VOIUme fo�Combusti0n Air.(DO NOT COUWY DIREGT VEN'i APPUANCEs) <br /> 4s.5tandard Method <br /> TotalBtu/hr input of ail mmbustion appliances Inputr Btu/hr <br /> Use Standard Method column tn Ta61e E 1 m flnd Total Required '�'R�- � <br /> Volume(i�RV) <br /> If CAS Volume(from Step 2);sgreot�i than TRV then n0 OUtdOOt OpLtIIfIQS 3�@�2EdEd. <br /> ff CA5 volume(trom 5cep 2}fs lass then Tttv chen go co srEa s. <br /> 4b.Known Air Infiltration Rate(KAIR1 Method(DO NOT COUNT DIRECi YEfVT APPLIANCES) <br /> Tocsl atu/t+r�npu�of a11 fan-ascisad snd power vQr�t appliances inptd:�8tu/hr <br /> Use Fan-Assis[ed Appiiances column fn Table E-i to flnd RVFA:�`''` � ft <br /> Required Volume Fan Asdsted(RVFAj <br /> Sotal Btu/hr input of all roatunl draft appliances Input: � Btu/hr <br /> Use Natura)draft Appfiances tolumn in Table E-1 to find RVNFA: � � - <br /> Requtred Volume Natural draftappiiantes(RVNDA) <br /> TUTdI ReqUired VOIurt1E(TR�=RVFA t RVNDA TRv=�+ � _ ��d TRV ft' <br /> if cas vo►ume(from Step 2);s yreater t9fon TRV then no outdoor openings are needed• <br /> if CAS Volume(from Ste 2 isless than TRV then o to STEP 5. <br /> 5tep 5:C31[u4HtE the ratio ot aveilebie intenor votume to the total required volume. <br /> R2ti0=CAS VOIUrt1E(ff0(i15tCE12)d7VFded by TRV(from Siep 4a or Step 46) M�� / �� _ ' �� <br /> Ratio= �ZS <br /> StEp 6:Celcul8te Reduccion Factor(R�. � <br /> RF=1 minus Rati� RF=i- 4 � _ � �' <br /> 5cep�;Calcuiare s�ngte outdoor opening as if aH combufion air is from outside. ,np� �'�� B��hr <br /> TOial Btu/hr input oP a11 CombusUon Appliances in the same('AC <br /> (EXCEPT DIREGT VEIVTI <br /> Combustion Ak Opening Area(CAOA): �� /3000 gtu�hr r ir�= d1O� ►�7• it� <br /> Toa�ew t�� id b 000 Ct++F�r or in= �A�A� <br /> Step 8:Calwlate Mlnimum CAOA. <br /> X `� 2 <br /> Minimum CAOA=CAOA multlpiied b RF Minimurn CAOA= ��6 7 ?�� = � in <br /> StGjt 9:G5ltulate Combustion Air Openi�g Oiam2te�(CAOD) � ^_C�i� `� � s� !"/� <br /> Ci � J"V'w <br /> CADD=1.13 mulUpljed by the square root oJ Mlrnmum cnoA c1+0�=1.13 v M�nimum C�+oA= in.diame <br /> go up one inch in size if usin flex dutt <br /> l if dC51fCd,ACH can be detertnined using ASHRAE calculation or blower doortest.Follow procedures in Sectton G304. <br /> i:\Building�5afetyPolideslnformaUon\�rcent�2016�ventnnakupcombr�i�tals2oi6.doa <br /> Page5of6 <br />