HomeMy WebLinkAboutFile Documents.210 S West End St.0111.2019 (16).ARBK DEW POINT CALCULATION BADERx
JOB NAME: Sack Renovation
��+ ENGINEERING • COMFORT SYSTEM51a
JOB NUMBER: 19005.00
DATE: 9/20/2019
CALCS BY: SKA
DP@ DP@ DP@ DP@ DP@
20% RH 25% RH 30% RH 35% RH 45% RH
30 33 37 41 48
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Outdoor design temperature (ODT) -15
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Indoor design temperature (IDT) 70 ji 30290
Delta T = IDT - ODT 85
III 9/20/19 •<<(1/
Thermal Resistance of Proposed Roof Assembly 141,AWNN.N`8/ON E ��
Layer R-value
Outside air layer 0.17
Roofing 0.81
3/4" plywood 0.94
R-9 (average) continuous insulation 9.00
R-49 spray foam insulation 49.00
A: point of condensation analysis
5/8" gypboard 0.56
Inside air layer 0.61
R-Total 61.09
R-value at A 1.17
TA = Temperature at point A
TA = IDT - (R-value at A)/(R-Total) * (Delta T) 68
DPA = Dew point at point A(35% RH) 41
Is TA warmer than the DPA? YES
Note: To minimize the potential for condensation problems,
humidity levels within the home must be properly controlled
and adjusted based on outdoor temperatures.