1、Addenda to American National StandardsZ21.12-1990Z21.12a-1993forDRAFT HOODSANSIZ21.12b-1994PART IIPERFORMANCE2.5MDRAFT HOOD OPERATIONA draft hood shall comply with the followingprovisions when attached in a normal manner toa test appliance operating at the maximumappliance input rating as specified
2、by the drafthood manufacturer.For recommended maximum appliance inputratings, refer to Table II.TABLE IINominalDraft Hood OutletDiameter, InchesRecommended MaximumAppliance Input Rating,Btu Per Hour (W)3456789101214161820222435,00064,000100,000143,000195,000255,000323,000398,000573,000780,0001,019,0
3、001,290,0001,593,0001,927,0002,294,000(10 257)(18 757)(29 307)(41 909)(57 149)(74 733)(94 662)(116 642)(167 930)(228 595)(298 639)(378 062)(466 862)(564 748)(672 305)The tests specified under 2.5.1 through 2.5.6shall be conducted under each of the following testconditions. Flue gas samples and tempe
4、raturesshall be average values taken inside the flue outletof the test appliance.Test Condition AThe test appliance shall be adjusted, withoutthe draft hood in place, for 8.5 percent carbondioxide for a draft hood for use with natural,manufactured and mixed gases only, or for 9.5percent carbon dioxi
5、de for a draft hood for usewith all fuel gases, with a maximum flue gastemperature of 480F (266.5C) above roomtemperature, and with the burner adjusted so theconcentration of carbon monoxide in an air-freesample of the flue gases does not exceed 0.005percent.Test Condition BThe test appliance shall
6、be adjusted, withoutthe draft hood in place, for 6 percent carbondioxide for a draft hood for use with natural,manufactured and mixed gases only, or for 7percent carbon dioxide for a draft hood for usewith all fuel gases, with a maximum flue gastemperature of 310F (128C) above roomtemperature, and w
7、ith the burner adjusted so theconcentration of carbon monoxide in an air-freesample of the flue gases does not exceed 0.005percent.NOTE:MChanges, other than editorial, are denoted by a vertical line in the margin.cApproved February 14, 1994 by American National Standards Institute, Inc.Secretariat:M
8、American Gas AssociationSecretariat:M1515 Wilson Boulevard, Arlington, Virginia 22209Copyright 1994 American Gas AssociationPermission is granted to republish material herein in laws or ordinances, andin regulations, administrative orders, or similar documents issued by publicauthorities. Those desiring permission for other republication should consult theAmerican Gas Association Laboratories, 8501 East Pleasant Valley Road, Cleveland,Ohio 44131.Printed in U.S.A.
