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HomeMy WebLinkAboutPermit Correspondence 1992-11-3 \ 'C. ;./ , . . Date: November 3, 1992 To: Don Moore - City of Springfield From: Cindy Brown ~.JJ ~ ~ Subject: k)))JeC5(j P/t~ . . 15"'&/, DEPARTMENT OF ENERGY Charles Miller calculated wall and ceiling U.values for steel framing Below are the U-values as calculated using Chapter 22 of the American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) Handbook of Fundamentals 1989. Wall: Furring R-value Stud Header R-value R-value .25 .25 .81 .81 .62 .62 .60 .84 6.29 1.36 .45 .45 .68 .68 9.70 5.01 .103 .200 .07 .0212 .007 .004 .25 .81 .62 .84 .45 ,68 3.65 .274 .0288 .008 Cavity R-value ,25 .81 .62 32.12 ,45 .68 34.93 ,029 .88 .025 ,008 + .007 + .004 + .025 = .044 overall U-value Description Outside Air 7.5 MPH 3/4" LP Lap Siding 1/2" sheathing Steel stud & furring to stud intersection insulation 1/2" sheetrock inside air Total R-value Total U-value Area Weighing Corrected U-value Barbara Roberts Governor e. . . . . '. " ..'.. , " ~.: 2:2-,13 625 Marion Street NE Salem, OR 97310 (503) 378-4040 FAX (503) 373-7806 TOO (503) 378.4040 Toll Free 1.800-221-8035 .j ',\' . Don Moore - City of Springfield November 3, 1992 Page 2 Ceiling: Cavity Truss R-value R-value .61 .61 .40 49 38.28 .45 .45 .61 .61 50.67 40.35 .02 .025 .898 .07 .017 .001 . . . Web/truss R-value Void R-value Description .61 1.82 Attic Air Steel truss lIisulation 1/2" sheetrock inside air .61 .45 .61 .45 .61 3.49 .29 .03 .008 Total R-value Total U-value Area Weighing Corrected U-value 1.67 .60 .002 .001 .017 + .001 + .008 + .001 = .027 overall U-value .'. ~= 31.of Since Mr. Millers ceiling system incorporates Advanced framing (raised heel truss) and R-49 insulation. The table 53-P base path one requires R-38 insulation in a standard framed ceiling which has a calculated U-value of .027 which is equivalent to Mr. Millers ceiling system. The table 53-P Prescriptive base path one requires R-21 insulation installed in standard framing which has a U-value of .060. Mr. Millers wall system uses advanced framing and he is installing a blown in blanket insulation system which gives him a cavity R-value of 32.12, which calculates out to a .044 U-value. The proposed home as submitted had a standard slab floor which Mr. Miller indicated installing R-15 rigid perimeter insulation, U-.40 windows, U-.54 entry door, U-.20 other door, R-8 ducts and no skylights. All of the above U-values meet the requirements of base path one and therefore the house qualifies for the Table 53-P Prescriptive Path 1 1992 Oregon Energy Code Requirements. As I indicated earlier, any additional homes that vary ll.Llill from the above system would require calculations to prove compliance (eg. a steel framed floor system). Please contact me if you have any additional questions.