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Dew Point Calculation Chart

RELATIVE HUMIDITY
AMBIENT AIR TEMPERATURE – FAHRENHEIT
20°
30°
40°
50°
60°
70°
80°
90°
100°
110°
120°
90%
18 28 37 47 57 67 77 87 97 107 117
85%
17 26 36 45 55 65 75 84 95 104 113
80%
16 25 34 44 54 63 73 82 93 102 110
75%
15 24 33 42 52 62 71 80 91 100 108
70%
13 22 31 40 50 60 68 78 88 96 105
65%
12 20 29 38 47 57 66 76 85 93 103
60%
11 19 27 36 45 55 64 73 83 92 101
55%
9 17 25 34 43 53 61 70 80 89 98
50%
6 15 23 31 40 50 59 67 77 86 94
45%
4 13 21 29 37 47 56 64 73 72 91
40%
1 11 18 26 35 43 52 61 69 78 87
35%
-2 8 16 23 31 40 48 57 65 74 83
30%
-6 4 13 20 28 36 44 52 61 69 77
SURFACE TEMPERATURE AT WHICH CONDENSATION OCCURS
DEW POINT
Temperature at which moisture will condense on surface. No coatings should be applied unless surface temperature is a minimum of 5° above this point.Temperature must be maintained during dry through.
EXAMPLE
If air temperature is 60°F and relative humidity is 50% the dew point is 40°F.No coating should be applied unless surface temperature is 45° minimum.
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