Nortec NHTC User Manual
Page 23
10-10
Page 15
2008-10-01
Table 3. Grains of Water Per Cubic Foot – Saturated Air (100% rh)
(2) Formula 2
Assume our printing plant is located in Denver, Colorado. From Table 4, the worst
case is -10
°
F with 37% rh
From Table 3:
0.29 gr/ft
3
x 37% rh - 0.11 gr/ft
3
Combining this result with that of Moisture Required (A) we see that we will need
5.19 - 0.11 = 5.08 grains of moisture for every cubic foot of outside air brought in.
E.
INCOMING AIR VOLUME
(1) The following outlines the steps necessary to determine the amount of outside air being
brought into the humidified space and the corresponding amount of moisture required.
There are three basic means by which outside air is introduced into the humidified
space. These are:
(a) Through natural ventilation, for example, opening and closing doors and windows,
and by infiltration through cracks and openings in the building construction.
(b) Through mechanical ventilation, for example, the introduction of make-up air, or
the exhausting of stale air by the building HVAC system.
(c) Through the economizer section of the HVAC system - if this feature is included in
the system.
(2) For maximum accuracy, all three should be estimated and the largest chosen.
°C
°F
Grains
°C
°F
Grains
°C
°F
Grains
°C
°F
Grains
°C
°F
Grains
°C
°F
Grains
-23
-10
.29
4
40
2.86
58
5.41
76
9.75
35
95
17.28
114
29.34
-5
.35
41
2.97
59
5.60
77
10.06
96
17.80
115
30.13
-18
0
.48
42
3.08
16
60
5.80
78
10.40
97
18.31
49
120
34.38
8
.61
43
3.20
61
6.00
79
10.80
98
18.85
125
39.13
-12
10
.78
44
3.32
62
6.20
27
80
11.04
99
19.39
54
130
44.41
-9
15
.99
7
45
3.44
63
6.41
81
11.40
38
100
19.95
135
50.30
-7
20
1.24
46
3.56
64
6.62
82
11.75
101
20.52
60
140
56.81
-4
25
1.56
47
3.69
18
65
6.85
83
12.11
102
21.11
145
64.04
-1
30
1.95
48
3.83
66
7.07
84
12.49
103
21.71
66
150
72.00
31
2.04
49
3.97
67
7.31
29
85
12.87
104
22.32
155
80.77
32
2.13
10
50
4.11
68
7.57
86
13.27
41
105
22.95
71
160
90.43
33
2.21
51
4.26
69
7.80
87
13.67
106
23.60
165 101.00
34
2.29
52
4.41
21
70
8.10
88
14.08
107
24.26
77
170 112.60
2
35
2.38
53
4.56
71
8.32
89
14.51
108
24.93
175 125.40
36
2.47
54
4.72
72
8.59
32
90
14.94
109
25.62
82
180 139.20
37
2.56
13
55
4.89
73
8.87
91
15.39
43
110
26.34
185 154.30
38
2.66
56
5.06
74
9.15
92
15.84
111
27.07
88
190 170.70
39
2.76
57
5.23
24
75
9.45
93
16.31
112
27.81
195 188.60
94
16.79
113
28.57