PDFWAC 51-11R-30314
Table R303.1.3(4)—Default U-factors for skylights.
TABLE R303.1.3(4)
DEFAULT U-FACTORS FOR SKYLIGHTS
Frame Type | |||||
Aluminum Without Thermal Break | Aluminum With Thermal Break | Reinforced Vinyl/Aluminum-Clad Wood or Vinyl | Wood or Vinyl-Clad Wood/Vinyl Without Reinforcing | ||
Fenestration Type | |||||
Single Glazing | |||||
glass | U-1.58 | U-1.51 | U-1.40 | U-1.18 | |
acrylic/polycarb | U-1.52 | U-1.45 | U-1.34 | U-1.11 | |
Double Glazing | |||||
air | U-1.05 | U-0.89 | U-0.84 | U-0.67 | |
argon | U-1.02 | U-0.86 | U-0.80 | U-0.64 | |
Double Glazing, e = 0.20 | |||||
air | U-0.96 | U-0.80 | U-0.75 | U-0.59 | |
argon | U-0.91 | U-0.75 | U-0.70 | U-0.54 | |
Double Glazing, e = 0.10 | |||||
air | U-0.94 | U-0.79 | U-0.74 | U-0.58 | |
argon | U-0.89 | U-0.73 | U-0.68 | U-0.52 | |
Double Glazing, e = 0.05 | |||||
air | U-0.93 | U-0.78 | U-0.73 | U-0.56 | |
argon | U-0.87 | U-0.71 | U-0.66 | U-0.50 | |
Triple Glazing | |||||
air | U-0.90 | U-0.70 | U-0.67 | U-0.51 | |
argon | U-0.87 | U-0.69 | U-0.64 | U-0.48 | |
Triple Glazing, e = 0.20 | |||||
air | U-0.86 | U-0.68 | U-0.63 | U-0.47 | |
argon | U-0.82 | U-0.63 | U-0.59 | U-0.43 | |
Triple Glazing, e = 0.20 on 2 surfaces | |||||
air | U-0.82 | U-0.64 | U-0.60 | U-0.44 | |
argon | U-0.79 | U-0.60 | U-0.56 | U-0.40 | |
Triple Glazing, e = 0.10 on 2 surfaces | |||||
air | U-0.81 | U-0.62 | U-0.58 | U-0.42 | |
argon | U-0.77 | U-0.58 | U-0.54 | U-0.38 | |
Quadruple Glazing, e = 0.10 on 2 surfaces | |||||
air | U-0.78 | U-0.59 | U-0.55 | U-0.39 | |
argon | U-0.74 | U-0.56 | U-0.52 | U-0.36 | |
krypton | U-0.70 | U-0.52 | U-0.48 | U-0.32 | |
Notes for Table R303.1.3(4) | |
1. | U-factors are applicable to glass and plastic, flat and domed units, all spacers and gaps. |
2. | Emissivities shall be less than or equal to the value specified. |
3. | Gap fill shall be assumed to be air unless there is a minimum of 90% argon or krypton. |
4. | Aluminum frame with thermal break is as defined in footnote 1 to Table R303.1.3(1). |
[Statutory Authority: RCW 19.27A.045 and chapter 19.27A RCW. WSR 20-21-081, § 51-11R-30314, filed 10/19/20, effective 2/1/21. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30314, filed 2/1/13, effective 7/1/13.]