PDFWAC 51-11C-303134

Table C303.1.3(4)Default U-factors for skylights.

Table C303.1.3(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
1
U-factors are applicable to both 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 percent argon or krypton.
4
Aluminum frame with thermal break is as defined in footnote 1 to Table C303.1.3(5).
[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-303134, filed 2/1/13, effective 7/1/13.]