HomeMy WebLinkAboutFile Documents.905 Chatfield Rd.0111.2018 (89).ARBKDEW POINT CALCULATION
JOB NAME: Silverstein
JOB NUMBER: 17085.00
DATE: 4/19/18
CALCS BY: JAH
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
10.00
0.77
49.00
0.63
0.56
0.61
61.74
1.80
67
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
1/2" plywood
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)
2" rigid insulation (R-5/in)
5/8" plywood
7.5" spray foam insulation (R-6.53/in)
Outdoor design temperature (ODT)
Delta T = IDT - ODT
Layer
Thermal Resistance of Proposed Roof Assembly
Outside air layer
4/19/18
04/26/2018