ASHRAE-90.1-2022- - Page 066
Extracted Content
| with Section 5.5.5.2.1(d)(3) | Col2 | Col3 |
|---|---|---|
| Climate Zone | R-Value Increase | U-factor % Decrease |
| 4 | R-1.5 | 13% |
| 5 | R-2.0 | 15% |
| 6 | R-2.5 | 16% |
| 7 | R-3.0 | 20% |
| 8 | R-4.0 | 25% |
| Climate Zone | Maximum Percent of Building Perimeter |
|---|---|
| 4 | 35% |
| 5 | 30% |
| 6 | 20% |
| 7 | 10% |
| 8 | 0% |
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Table 5.5.5.2.1 Additional Wall Insulation Required for Mass Walls With Insulation on the Interior Complying
Table 5.5.5.2.2 Mass Floor Balcony or Floor Overhang Allowances
ted to be interrupted by an intermediate floor . ( Informative Note: See Informative Appendix K, Figure K-4[g].)
5.5.5.2.2 The total length of mass floor assembly projections serving as balconies or floor overhangs that penetrate the building envelope shall not exceed the percentages of the total building perimeter depicted in Table 5.5.5.2.2. For this calculation, total building perimeter is the sum of the perimeters of each above_grade_ floor where it intersects the exterior building envelope .
Exceptions to 5.5.5.2.2:
- Mass floor assembly projections located directly above and providing protection to a pedestrian walkway at street-level.
- Mass floor assembly projections thermally broken with a continuous thermal spacer block not less than R-12. The thermal spacer block shall be permitted to be interrupted by structural connections.
struction using point connections to accommodate the full depth of any exterior continuous insulation exclusive of the point connections.
Exception to 5.5.5.3: Girts in metal building walls as described in Normative Appendix A.
( Informative Note: See Informative Appendix K, Figure K-5.)
5.5.5.4 Opaque Wall and Vertical Fenestration Intersection. Vertical fenestration shall be installed in accordance with one or more of the following:
a. For vertical fenestration, the outermost glazing layer shall be aligned within the thickness of or within 2
in. of either face of the continuous insulation layer. ( Informative Note: See Informative Appendix K, Figures K-6[a] and K-6[b].) b. For vertical fenestration, where continuous insulation is not present, the outermost glazing layer shall be
aligned within the thickness of the wall insulation layer and not more than 2 in. from the exterior side of the outermost insulation layer. ( Informative Note: See Informative Appendix K, Figure K-6[c].) c. Intersections between vertical fenestration and opaque walls where the surfaces of the rough opening
located between the edge of the frame of the vertical fenestration and the opaque wall insulation shall be
64 ANSI/ASHRAE/IES Standard 90.1-2022 (I-P)