Figure 5.3-3 Detail of Heat Transfer From a Metal Surface to a OR R deck R dock Figure 5.3-4 - The Function (f) Given as a Function of Br and for Different Values of the Ratio, ry/r2 tals Volume, shall be used for these calculations. 5.3.3.3 The thermal transmittance of fenestration assemblies shall be corrected to account for the presence of sash, frames, edge effects and spacers in multiple-glazed units. If thermal transmittances of sash and frames are known, Equation 5.3–1 shall be used, otherwise the thermal transmittance offenestration assemblies shall be calculated as follows: Uor=Σ Ug×F×A1/A。r= (U ̧.1×F..1×A1+Ug,2×μ‚2× A2+... +Us.n>Fl.nXA2)/A。f Where: Equation 5.3-20 A=area of ith fenestration assembly i=numerical subscript (1,2,.......n) refers to each of the various fenestration assemblies present in the wall n=the number of fenestration assemblies in the wall assembly. Uor the overall thermal transmittance of the fenestration assembly, including sash and frames, Btu/h.ft2°F. U, the thermal transmittance of the central area of the fenestration excluding edge effects, spacers in multiple-glazed units, and the sash and frame, Btu/ h.ft2°F. F=framing adjustment factor for sash, frames, etc. Ar=the area of all fenestration including glazed portions, sash, frames, etc. 5.3.3.3.1 Values for U, shall be the winter value obtained from the glazing manufacturer's test data or from Table 13 or Figure 14 of Chapter 27 of the ASHRAE Handbook, 1985 Fundamentals Volume. Values for F, shall be obtained from the frame manufacturer's test data or from the average adjustment factor for a particular product in Table 13, Part C, in Chapter 27 of the ASHRAE Handbook, 1985 Fundamentals Volume. For glass products with a U value of 0.45 or less, use the F, for triple insulated glazing. Alternatively, values of the U,°F product may be used from manufacturer's test data for open window and frame assemblies tested as a unit provided that the tests referenced edge-effects and windspeed are accounted for winter tested Uvalues are used. 5.3.4 Gross Area of Envelope Components |