Figure 5.5-1 Maximum Overall Thermal Transmittance 2 3 4 5 6 7 8 9 10 11 12 13 14 Thousand HDD65 15 for 550HDD65 < 8000, Uof1 = 1/[0.840 + 0.00302 x HDD65] for 8000 < HDD65 < 15000, Uof = 0.04 for HDD65 > 15000, see Table 5.3-5 5.5.2.1.2 Slab-on-grade floors shall have insulation around the perimeter of the floor with the thermal resistance (R) of the insulation as specified in Figure 5.5-2. The insulation specified in Figure 5.5-2 shall extend either in a vertical plane downward from the top of the slab for the minimum distance shown or downward to the bottom of the slab for the minimum distance shown then in a horizontal plane beneath the slab. The horizontal length, or vertical depth, of insulation required varies from 24 in. to 48 in. depending upon the R-value selected. For heated slabs, an R of 2 shall be added to the thermal resistance required in Figure 5.5-2. 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 for 3000 > HDD65 > 15000, see graph above for HDD65 ≥ 15000, see Table 5.3-5 R values for heated slab-on-grade = R unheated Rn = R + 2 + 2; (a) Vertical insulation is not required to extend below the foundation footing. There are no insulation requirements for slabs in locations having less than 3,000 HDD65 for footings extending less than 18 in. below grade. 5.5.3 Thermal Transmittance Criteria For Opaque Walls Enclosing Con ditioned Spaces Exposed to Interior Unconditioned Spaces 5.5.3.1 All opaque walls enclosing conditioned spaces exposed to interior unconditioned spaces shall have an overall thermal transmittance (Uow) not greater than the value specified in Figure 5.5-3. |