10-10
Page 21
2008-10-01
(b)
Formula 7
Assume that during the summer the HVAC system is in the cooling mode. The
air leaving the cooling coil is at 55°F and 90% rh. In order to maintain the
desired 47% rh in the space, moisture must be added using the following
formula:
Desired space 80°F 47% rh = 5.19 gr/ft
3
(Formula 1)
55°F 90% = 4.89 x 0.90
= 4.40 gr/ft
3
________________________
__________
Grains to add
= 0.79 gr/ft
3
15,000 x 0.79 x 60 min/hr
_________________________
= 101.57 lbs/hr
7,000 grains/lb
(8) In considering Process and Environment, in Tables 5 through 7 you will find conditions
and processes that may affect your calculation and should be addressed.
(a) Table 5 shows the outdoor temperature at which the rh would cause condensation
on the windows to the outside. Should your outdoor conditions make this a
possibility, an outdoor setback sensor may be a solution.
(b) Table 6 describes the moisture gain of various material and if your process or
environment includes a great amount of these materials that are constantly
introduced to the area, its affects must be considered.
(c) Table 7 identifies many recommended indoor conditions for various locations and
processes, these can be of use when deciding what conditions would be most
beneficial in your application.
(d) In Figure 2, you will find the ASHRAE physchrometric chart describing the
enthalpy of dry air and the effects to and from rh in the air.
Table 5. Inside Relative Humidities At Which Moisture Will Condense On Windows
Outside
Temperature
Inside Temperature (°F/°C)
Outside
Temperature
Inside Temperature (°F/°C)
°F
°C
60/
15.5
65/
18.3
70/
21
75/
23.8
80/
26.6
°F
°C
60/
15.5
65/
18.3
70/
21
75/
23.8
80/
26.6
Single Windows, Still Air
Single Windows, Wind
-50
-45
9
9
9
8
8
-50
-45
4
3
3
3
2
-40
-40
12
12
11
10
10
-40
-40
5
4
4
4
3
-30
-34
16
14
14
13
13
-30
-34
7
6
6
6
5
-20
-29
20
18
18
17
16
-20
-29
10
9
9
8
7
-10
-23
25
23
22
21
20
-10
-23
14
13
12
11
10
0
-18
32
29
27
25
24
0
-18
20
18
16
15
13
10
-12
39
36
33
31
29
10
-12
28
24
22
20
18
20
-7
47
43
40
37
35
20
-7
36
32
30
26
24
30
-1
57
52
50
45
42
30
-1
48
41
38
34
30
40
4
70
63
60
53
50
40
4
62
54
49
43
40
NOTE: Bold
areas indicate that moisture will be in the form of frost on windows.
Summary of Contents for NHPC
Page 1: ...2538144 B NH Series NHTC NHPC ELECTRODE STEAM HUMIDIFIER Engineering Manual TM ...
Page 9: ...10 00 Page 1 2008 10 01 10 00 INTRODUCTION ...
Page 10: ...10 00 Page 2 2008 10 01 Figure 1 NHTC ...
Page 13: ...10 00 Page 5 2008 10 01 Figure 2 Optimum Boiling Time Figure 3 Conductivity ...
Page 18: ...10 00 Page 10 2008 10 01 Figure 6 Typical NHRS Installation Sheet 1 of 2 ...
Page 19: ...10 00 Page 11 2008 10 01 Figure 7 Typical NHRS Installation Sheet 2 of 2 ...
Page 20: ...10 10 Page 12 2008 10 01 10 10 HUMIDITY STEAM ABSORPTION AND DISTRIBUTION ...
Page 35: ...10 10 Page 27 2008 10 01 Figure 2 Psychrometric Chart ...
Page 64: ...10 10 Page 56 2008 10 01 Figure 30 NORTEC OnLine Monitoring ...
Page 71: ...10 20 Page 63 2008 10 01 10 20 SPECIFICATIONS ...
Page 81: ...10 30 Page 73 2008 10 01 10 30 SUBMITTALS ...
Page 86: ...10 30 Page 78 2008 10 01 Figure 2 Primary Line Voltage Wiring to Unit ...
Page 87: ...10 30 Page 79 2008 10 01 Figure 3 Physical Data NHTC NHPC 005 030 ...
Page 88: ...10 30 Page 80 2008 10 01 Figure 4 Physical Data NHTC NHPC 050 100 ...
Page 89: ...10 30 Page 81 2008 10 01 Figure 5 Physical Data NHTC NHPC 150 200 ...
Page 96: ...10 30 Page 88 2008 10 01 Figure 12 In Duct AHU Installation With Mounting Frame Installation ...
Page 98: ...10 30 Page 90 2008 10 01 Figure 13 In Duct AHU Installation With Mounting Frame Installation ...
Page 100: ...10 30 Page 92 2008 10 01 Figure 16 Atmospheric SAM e Adapter Dimensions ...
Page 101: ...10 30 Page 93 2008 10 01 Figure 17 Atmospheric Steam Header and Adapter Configuration ...
Page 102: ...10 30 Page 94 2008 10 01 Figure 18 Physical Data for Remote Mounted Blower Pack ...
Page 103: ...10 30 Page 95 2008 10 01 Figure 19 Physical Data Units with Optional Built On Blower Packs ...
Page 104: ...10 30 Page 96 2008 10 01 Figure 20 Physical Data Units with Optional Built On Blower Packs ...