PDFWAC 51-11R-40215
Target/Proposed UA equations.
EQUATION 1 - GROUP R OCCUPANCY
TARGET UA
UAT = UWAW + UBGWABGW + UVGAVG + UOGAOG + UFAF + URCARC + UDAD + FSPS + FBGSPBGS |
Where: | |||
UAT | = | The target combined thermal transmittance of the gross exterior wall, floor and roof/ceiling area. | |
UW | = | The thermal transmittance value of the opaque above grade wall found in Table R402.1.2. | |
AW | = | Opaque above grade wall area. | |
UBGW | = | The thermal transmittance value of the below grade opaque wall found in Table R402.1.2. | |
ABGW | = | Opaque below grade wall area. | |
UVG | = | The thermal transmittance value of the fenestration found in Table R402.1.2. | |
AVG | = | (a) The proposed glazing area; where proposed fenestration glazing area is less than 15 percent of the conditioned floor area, minus AOG. | |
(b) 15 percent of the conditioned floor area; where the proposed fenestration glazing area is 15 percent or more of the conditioned floor area, minus AOG. | |||
UOG | = | The thermal transmittance value of the skylight glazing found in Table R402.1.2. | |
AOG | = | Skylight glazing area (if the proposed AOG exceeds 15 percent, the target AOG shall be 15 percent of the total floor area of the conditioned space). | |
UF | = | The thermal transmittance value of the floor found in Table R402.1.2. | |
AF | = | Floor area over unconditioned space. | |
URC | = | The thermal transmittance value of the ceiling found in Table R402.1.2. | |
ARC | = | Roof/ceiling area. | |
UD | = | The thermal transmittance value of the fenestration found in Table R402.1.2. | |
AD | = | Opaque door area. | |
FS | = | Concrete slab on grade component F-factor found in Table R402.1.2. | |
PS | = | Lineal ft. of concrete slab on grade perimeter. | |
FBGS | = | Concrete below grade slab component F-factor found in Table R402.1.2. | |
PBGS | = | Lineal ft. of concrete below grade slab perimeter. | |
EQUATION 2 - GROUP R OCCUPANCY
PROPOSED UA
UA = UWAW + UBGWABGW + UVGAVG + UOGAOG + UFAF + URCARC + UDAD + FSPS + FBGSPBGS |
Where: | |||
UA | = | The combined thermal transmittance of the gross exterior wall, floor and roof/ceiling assembly area. | |
UW | = | The thermal transmittance of the opaque above grade wall area. | |
AW | = | Opaque above grade wall area. | |
UBGW | = | The thermal transmittance value of the below grade opaque wall. | |
ABGW | = | Opaque below grade wall area. | |
UVG | = | The thermal transmittance value of the fenestration glazing. | |
AVG | = | Fenestration glazing area, including windows in exterior doors. | |
UOG | = | The thermal transmittance value of the skylight glazing. | |
AOG | = | Skylight glazing area. | |
UF | = | The thermal transmittance of the floor. | |
AF | = | Floor area over unconditioned space. | |
URC | = | The thermal transmittance of the ceiling. | |
ARC | = | Ceiling area. | |
UD | = | The thermal transmittance value of the opaque door area. | |
AD | = | Opaque door area. | |
FS | = | Concrete slab on grade component F-factor. | |
PS | = | Lineal ft. of concrete slab on grade perimeter. | |
FBGS | = | Concrete below grade slab component F-factor. | |
PBGS | = | Lineal ft. of concrete below grade slab perimeter. | |
NOTE: | Where more than one type of wall, window, roof/ceiling, door and skylight is used, the U and A terms for those items shall be expanded into subelements as: |
UW1AW1 + UW2AW2 + UW3AW3 + ...etc. |
NOTE: | Below grade walls: The wall is assumed to extend from the slab upward to the top of the mud sill for the distance specified in Table A104.1, with 6 inches of concrete wall extending above grade. This will be calculated separately from above grade walls using the wall height that best describes the system. |
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and chapter 19.27A RCW. WSR 23-02-060, 23-12-102, and 23-20-022, § 51-11R-40215, filed 1/3/23, 6/7/23, and 9/25/23, effective 3/15/24. Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160 and chapter 19.27 RCW. WSR 20-01-047, § 51-11R-40215, filed 12/9/19, effective 7/1/20.]