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Directions-The Minnesota Fuel Gas Code meihod to calculate fo size of a requlred cambustfon ali opening,ls called the Known Alr <br /> Infiltratlon Rate Method. for new construction,Ab af step 4 Is requlred to be J7!!ed oui. <br /> IFGC Appendlz E,Worksheet F-1 " T <br /> Residentlal Combustlon Alr Calculation Method <br /> �fac Furnace,BoNer,and/or Water Heater i�the Same S ce) <br /> Step 1:Complete ve�ted combustio�appflance Information. <br /> Fumace/Botler. �/� <br /> _Drak Hood „_ Fan Assisted _,"Direcc Vent Input: Btu/hr <br /> or Powcr Vent <br /> Water Hcater. / <br /> �,Dratt Hood ✓ �an Assisted _pirect Vent input: ��� Btu/hr <br /> or Power Vent <br /> Step 2:Calalate the volume of the Combustion Appllance Space(CASj containMg combustlon appliances. <br /> The CAS Indudes all spaces connected to one another by code complia�t openings. CAS volume:,_ O {t' <br /> lxWxN L W H <br /> Step 3:Determine Air Cha�ges per Hour(ACM)1 <br /> Default ACH values have 6een incorporated into Table E-1 for use with Methad 4b�KAIR Method). <br /> If the ar of construction or ACH is not known uus methad 4a(Standard Method). <br /> Step 4:Determine Required Volume for Combustion Alr.(00 NOT COUNT DiRfCT VENT APPtIANCES) <br /> 4a.Standard Method <br /> Totai Btu/hr input of atl combustfon appllances input; Btu/hr <br /> use Standard Method column In Table E-1 ta flnd Tota)Requlred TRV: ft' <br /> Volume(TR1� <br /> If CAS Volume(from Step 2�!s greater than TRV then no outdaor openings are needed. <br /> If CAS Votume(from Step 2)Is kss than TRV then go to STEP 5. <br /> 4b.Known AIr I�iltration Rate(KAIR)Method(Dp NOT COUNT DiRECT VEN7 APPLIA ��) <br /> Total etu/hr input of all Fan•asslsted and power vent applla�ces Input:�2:f',�,�etu/hr <br /> r^•-�- <br /> Use fan-Assisted Appliances column in Table E-1 to ftnd RVFA:-��,�,�5 ft' <br /> Required Volume Fa�Assisted(RVFAy <br /> Totai Btu/hrl�put of all Natural drah appllances Input:„�,�Btu/hr <br /> Use Natural draft Appliances cdumn in Table E-1 to flnd RVNfA: "'�� ft� <br /> Requlred Volume Natural draR eppua�ces(RVIVDA) <br /> Total Requlretf Volume{TR�=RVFA+RVNDA TRV� ��7� + d' - ����' TRV ft' <br /> !f CAS Volume(from Step 2}1s p�eater than TRV then no artdoor openings are needed. <br /> If CAS Volume(from Step 2 h less thaq TRV then o to STEP S. <br /> Step S:Caiculate the ratfo o{avallable interior volumc to the tota!►equired volume. <br /> Ratlo=CAS Volume(from Step 2)d/vfded by 7RV(from Step 4a or Step qb) �!��``!/_���,�✓_ ,�rr e.�. <br /> Ratio= <br /> Step 6:Calculate Reduction Factor(RF). <br /> RF=1 minus Ratio R���. r ��,..m � �� <br /> Step 7:Calculate s(ngle outdoor opentng as(f ail cambustlon air is from outside. /���y�.,, <br /> Total 8tu/hr input of all Combustlon Appllances in the same CAS Input: `Tt'�'�+V.Btu/hr <br /> (EXCEPT DIREC7 VENT) <br /> Gombustion A)r Opening Area f�OA): / <br /> 7ota)Rtu/hr dlvJded b 3000 Btu/hr er in' CAOA= !�(�/3000 Btu/hr per in== ! fn' <br /> Step 8:Calculate Minimum CAOA. � � <br /> Mfnimum CAOA=CAOA muftlpl7ed b RF Mlnimum CAOA= ��x . �' �� � <br /> .tCJc___.��_�._._�._.�__.._.. <br /> 5tep 9:Calculate Combustlon Atr Opening Diameter{CAOD) <br /> CAOD=I.13 multTp!!ed by the square root ojARfnimum CAOA CAOD=1.13 J Mlnimum CAOA= �,v �In.dlameter <br /> o u one inch In siie if usin flex duu <br /> i If desired,AtH can be determined using ASHRAf calculatlon or blower door tes[.Follow procedures In Sedlon <br /> G304. <br />