HomeMy WebLinkAboutFile Documents.905 Chatfield Rd.0111.2018 (168).ARBK DEW POINT CALCULATION ® RADERz
JOB NAME: Silverstein clxi ENGINEERING • COMFORT SYSTEMS
JOB NUMBER: 17085.00
DATE: 4/19/18
CALCS BY: JAH
DP @ DP @ DP @ DP @ DP @ =
ND t1�F4'
20% RH 25% RH 30% RH 35% RH 45% '
RH p ** ' ''4 '
30 33 37 41 48 i � ' "
: 4/19/18 i
w 50 02 rill:
Outdoor design temperature (ODT) -20 11 ro % �i
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Indoor design temperature (IDT) 70 +,Ft���c ••......••'
Delta T = IDT- ODT 90 '1 ,IS'/ON AL ��
Thermal Resistance of Proposed Roof Assembly
Layer R-value
Outside air layer 0.17
2" rigid insulation (R-5/in) 10.00
5/8" plywood 0.77
7.5" spray foam insulation (R-6.53/in) 49.00
A: point of condensation analysis
1/2" plywood 0.63
5/8" gypboard 0.56
Inside air layer 0.61
R-Total 61.74
R-value at A 1.80
TA=Temperature at point A
TA= IDT- (R-value at A)/(R-Total)* (Delta T) 67
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.
RECEIVED
04/26/2018
ASPEN
BUILDING DEPARTMENT