4
RECOMMENDED RELATIVE HUMIDITY BY OUTDOOR TEMPERATURE
OUTDOOR TEMP
_
F (
_
C)
OUTDOOR RELATIVE HUMIDITY
(%)
INDOOR RELATIVE HUMIDITY
(%) W/O HUMIDIFIER*
MAX RECOMMENDED INDOOR
RELATIVE HUMIDITY
{
---10 (---23)
30 to 70
1 to 2
20 (Lo)
0 (---18)
30 to 70
2 to 4
25
10 (---12)
30 to 70
3 to 6
30
20 (---7)
30 to 70
4 to 10
35
30 (---1)
30 to 70
6 to 15
40 (Med)
* Indoor relative humidity level when outdoor air is heated to 72
_
F/22
_
C.
{
As stipulated by the Air Conditioning Contractors of America.
INDOOR RELATIVE HUMIDITY LIMIT FOR NO WINDOW CONDENSATION
(Indoor Air at 74
_
F/23
_
C Dry Bulb)
OUTDOOR TEMPERATURE
_
F (
_
C)
SINGLE PANE WINDOWS (%)
DOUBLE PANE WINDOWS (%)
40 (4)
39
59
30 (---1)
29
50
20 (---7)
21
43
10 (---12)
15
36
0 (---18)
10
30
---10 (---23)
7
26
---20 (---29)
5
21
---30 (---34)
3
17
MAXIMUM MOISTURE REQUIREMENTS*
VOLUME OF RESIDENCE
CUBIC FEET
(CUBIC METER)
TIGHT HOUSE
AVERAGE HOUSE
POUNDS
(KILOGRAMS) PER
HOUR
GALLONS (LITERS)
PER DAY
POUNDS
(KILOGRAMS) PER
HOUR
GALLONS (LITERS)
PER DAY
8,000 (227)
1.76 (0.8)
5.09 (19)
3.52 (1.6)
10.17 (38)
10,000 (283)
2.21 (1.0)
6.35 (24)
4.41 (2.0)
12.72 (48)
12,000 (340)
2.64 (1.2)
7.63 (29)
5.29 (2.4)
15.26 (58)
14,000 (396)
3.09 (1.4)
8.91 (34)
5.92 (2.7)
17.08 (65)
16,000 (453)
3.53 (1.6)
10.18 (39)
7.06 (3.2)
20.35 (77)
18,000 (510)
3.97 (1.8)
11.45 (43)
7.94 (3.6)
22.89 (87)
20,000 (566)
4.41 (2.0)
12.72 (48)
8.82 (4.0)
25.44 (96)
22,000 (623)
4.85 (2.2)
13.99 (53)
9.71 (4.4)
27.98 (106)
24,000 (680)
5.29 (2.4)
15.27 (58)
10.59 (4.8)
30.52 (116)
26,000 (736)
5.74 (2.6)
16.54 (63)
11.47 (5.2)
33.07 (125)
28,000 (793)
6.18 (2.8)
17.81 (67)
12.35 (5.6)
35.61 (135)
30,000 (850)
6.62 (3.0)
19.08 (72)
13.24 (6.0)
38.16 (144)
* Based on design conditions of outdoor 20
_
F/---7
_
C dry bulb, 80% RH; indoor 70
_
F/21
_
C dry bulb, 40% RH, and minimum moisture production from residen-
tial operations for an absolute humidity difference of 0.0049 lb/hr.
NOTE
:
Tight house is defined as being well insulated, having vapor barriers, tight storm doors and windows with weatherstripping, and having dampered fireplaces.
Average house is defined as being insulated, having vapor barriers, loose storm door and windows and having dampered fireplace.
HUM
