HomeMy WebLinkAboutFile Documents.155 Lone Pine Rd.0129.2016 (3).ARBK DEW POINT CALCULATION RADER
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JOB NAME: Burcham Residence +,+ AI ENGINEERING • COMFORT SYSTEMSrr
JOB NUMBER: 16086.00
DATE: 11/16/16
CALLS BY: JOB
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DP@ DP@ DP@ DP@ DP@ 1-11/16/16:, '
20% RH 25% RH 30% RH 35% RH 45% RH 50 02 ,Ti
30 33 37 41 48 1� r rr
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Outdoor design temperature (ODT) 1 1`rl�ti�.`4�
Indoor design temperature (IDT) 70
Delta T = IDT- ODT 69
Thermal Resistance of Proposed Roof Assembly
Layer R-value
Outside air layer 0.17
Metal Roofing 0.00
3/4" plywood 0.94
4.5" spray foam insulation (R-6.7/in) 30.15
A: point of condensation analysis
R-21 batt insulation 21.00
5/8" gypboard 0.56
Inside air layer 0.61
R-Total 53.43
R-value at A 22.17
TA= Temperature at point A
TA = IDT- (R-value at A)/(R-Total) * (Delta T) 41.4
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.