HomeMy WebLinkAboutFile Documents.433 W Bleeker St.0170.2017 (20).ARBKDEW POINT CALCULATION
JOB NAME: 433 W Bleeker
JOB NUMBER: 16095.00
DATE: 6/27/17
CALCS BY: JCB
DP @ DP @ DP @ DP @ DP @
20% RH 25% RH 30% RH 35% RH 45% RH
30 33 37 41 48
-20
Indoor design temperature (IDT)70
90
R-value
0.17
0.00
15.00
0.94
37.50
0.00
0.56
0.61
54.78
1.17
68
41
YES
Note: To minimize the potential for condensation problems,
humidity levels within the home must be properly controlled
and adjusted based on outdoor temperatures.
Is TA warmer than the DPA?
Inside air layer
R-Total
R-value at A
A: point of condensation analysis
Vapor barrier
5/8" gypboard
TA = IDT - (R-value at A)/(R-Total) * (Delta T)
TA = Temperature at point A
DPA = Dew point at point A (35% RH)
3" Rigid Insulation
3/4" plywood
6" spray foam insulation (R-6.25/in)
Outdoor design temperature (ODT)
Delta T = IDT - ODT
Layer
Thermal Resistance of Proposed Roof Assembly
Outside air layer
Metal Roofing
6/27/17
07/28/17