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, � � ��ssN�� _ 3z�s' G���-M �-�,w ,�v�o _ r�ta-k��a Fco�,e�sno,� �a�Q c�-����-�o.�r <br /> 1346.6012 IFGC APPENDIX E,WORKSHEET E-1. <br /> IFGC Appendix E,Worksheet E-1 <br /> Residential Combustion Air Calculation Method <br /> for Furnace,Boiler,and/or Water Heater in the Same S ace <br /> Step 1: Complete vented combustion appliance information: <br /> Furnace/Boiler: <br /> Draft Hood 0 Fan Assisted 205000 Direct Vent Input: 205000 Btu/hr <br /> (Not fan assisted) &Power vent <br /> Water Heater: <br /> Draft Hood 150000 Fan Assisted Direct Vent Input: 150000 Btu/hr <br /> (Not fan Assisted) &Power vent <br /> Step 2: Calculate the voiume of the Combustion Appliance Space(CAS)containing combustion appliances. <br /> The CAS includes all spaces connected to one another by code compliant openings. CAS VOIUm@: 1600 ft^3 <br /> Step 3: Determine air Changes per Hour(ACH)1 <br /> Default ACH values have been incorporated into Table E-1 for use with Method 4b(KAIR Method). If the year of construction <br /> or ACH is not known, use method 4a(Standard Method) <br /> Step 4: Determine Required Volume for Combustion Air. <br /> 4a. Standard Method <br /> Total Btu/hr input of all combustion appliances(DO NOT COUNT DIRECT VENT APPLIANCES) Input: 150000 Btu/hr <br /> Use Standard Method column in Table E-1 to find Total Required Volume(TRV) TRV: 11250 ft^3 <br /> If CAS Volume(from Step 2)is greater than TRV then no outdoor openings are needed. <br /> If CAS Volume(from Step 2)is less than TRV then go to STEP 5. <br /> 4b. Known Air Infiltration Rate(KAIR)Method <br /> Total Btu/hr input of all fan-assisted and power vent appliances <br /> (DO NOT COUNT DIRECT VENT APPLIANCES) Input: 150000 Btu/hr <br /> Use Fan-Assisted Appliances column in Table E-1 to find <br /> Required Volume Fan Assisted(RVFA) RVFA: 11250 ft^3 <br /> Total Btu/hr input of all non-fan-assisted appliances Input: 0 Btu/hr <br /> Use Non-Fan-Assisted Appliances column in Table E-1 to find <br /> Required Volume Non-Fan-Assisted(RVNFA) RVNFA: ft^3 <br /> Total Required Volume(TRV)=RVFA+RVNFA TRV= 11250 + 0 = 11250 ft^3 <br /> If CAS Volume(from Step 2)is greater than TRV then no outdoor openings are needed. <br /> If CAS Volume(from Step 2)is less than TRV then go to STEP 5. <br /> Step 5:Calculate the ratio of available interior volume to the total required volume. <br /> Ratio=CAS Volume(from Step 2)divided by TRV(from Step 4a or Step 4b) Ratio = 1600 / 11250 = 0.1422222 <br /> Step 6:Calculate Reduction Factor(RF). <br /> RF=1 minus Ratio RF= 1 - 0.14222222 = 0.857777778 <br /> Step 7:Calculate single outdoor opening as if all combustion air is from outside. <br /> Total Btu/hr input of all Combustion Appliances in the same CAS(EXCEPT DIRECT VENT) Input: 150000 Btu/hr <br /> Combustion Air Opening Area(CAOA): <br /> Total Btu/hr divided by 3000 Btu/hr per in^2 CAOA= 150000 / 3000 at��h�ce���� = 50 in2 <br /> Step 8:Calculate Minimum CAOA. <br /> Minimum CAOA=CAOA multiplied by RF Minimum CAOA= 50 x 0.85778 = 42.8889 in2 <br /> Step 9:Calculate Combustion Air Opening Diameter(CAOD) <br /> CAOD= 1.13 multiplied by the square root of Minimum CAOA CAOD= 1.13 x 6.549 = 7.40033 in <br /> 1 If desired,ACH can be determined using ASHRAE calculation or blower door test. Follow procedures in Section 304. <br />