Venmar 700 cfm - Manual (Page 20)

Page 20
Although the 600 cfm, 700 cfm and 1200 cfm models have good ef
ficiencies, the supply air could be colder than the ambient room
air
. It is possible to eliminate the
discomfort associated with this temperature dif
ference by installing an electric duct heater
.
This will temper the air before i
t is distributed throughout the building.
The table below gives the heating requirements at dif
ferent temperatures and airflows.
OUTDOOR
AIR -40°F
(- 40°C)
OUTDOOR
AIR -22°F
(-30°C)
OUTDOOR
AIR -4°F
(-20°C)
OUTDOOR
AIR +14°F
(-10°C)
OUTDOOR
AIR +32°F
(0°C)
Desired Air
T
emperature
Desired Air
T
emperature
Desired Air
T
emperature
Desired Air
T
emperature
Desired Air
T
emperature
55°F(13°C)
68°F(20°C)
73°F(23°C)
55°F(13°C)
68°F(20°C)
73
°F(
23°C
)
55°F(13°C)
68°F(20°C)
73°F(23°C)
55°F(13°C)
68°F(20°C)
73°F(23°C)
55°F(13°C)
68°F(20°C)
73°F(23°C)
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
1250
590
14.6
19.9
21.9
1
1.2
16.5
18.5
7.8
13.1
15.2
4.4
9.7
1
1.8
1.0
6.3
8.4
1200
566
13.5
18.6
20.6
10.4
15.5
17.4
7.2
12.3
14.3
4.0
9.1
1
1.1
0.8
5.9
7.9
1
150
542
12.6
17.4
19.3
9.6
14.5
16.4
6.6
1
1.5
13.4
3.6
8.5
10.4
0.7
5.5
7.4
1
100
519
1
1.2
15.9
17.7
8.5
13.2
15.0
5.8
10.5
12.3
3.1
7.7
9.6
0.4
5.0
6.8
1050
495
10.7
15.2
16.9
8.1
12.6
14.3
5.5
10.0
1
1.7
2.9
7.4
9.1
0.4
4.8
6.5
1000
472
9.9
14.1
15.7
7.4
1
1.7
13.3
5.0
9.3
10.9
2.6
6.9
8.5
0.2
4.4
6.1
900
425
8.5
12.4
13.8
6.4
10.2
1
1.7
4.3
8.1
9.6
2.2
6.0
7.5
0.1
3.9
5.4
800
377
7.0
10.4
1
1.7
5.2
8.6
9.9
3.4
6.8
8.2
1.7
5.0
6.4
-
3.3
4.6
700
330
5.1
8.1
9.3
3.7
6.7
7.9
2.3
5.3
6.5
0.9
3.9
5.1
-
2.5
3.7
1200
CFM UNIT
Supply Air
Supply Air
(cfm)
(L/s)
OUTDOOR
AIR -40°F
(- 40°C)
OUTDOOR
AIR -22°F
(-30°C)
OUTDOOR
AIR -4°F
(-20°C)
OUTDOOR
AIR +14°F
(-10°C)
OUTDOOR
AIR +32°F
(0°C)
Desired
Air T
emperature
Desired
Air T
emperature
Desired
Air T
emperature
Desired
Air T
emperature
Desired
Air T
emperature
55°F(13°C)
68°F(20°C)
73°F(23°C)
55°F(13°C)
68°F(20°C)
73
°F(
23°C
)
55°F(13°C)
68°F(20°C)
73°F(23°C)
55°F(13°C)
68°F(20°C)
73°F(23°C)
55°F(13°C)
68°F(20°C)
73°F(23°C)
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
kW
700
330
7.4
10.4
1
1.5
5.6
8.6
9.7
3.9
6.8
8.0
2.1
5.1
6.2
0.3
3.3
4.4
650
307
6.6
9.4
10.5
5.0
7.8
8.9
3.4
6.2
7.3
1.8
4.6
5.6
0.2
3.0
4.0
600
283
5.9
8.5
9.4
4.5
7.0
8.0
3.0
5.6
6.5
1.6
4.1
5.1
0.1
2.7
3.7
550
259
5.2
7.6
8.5
3.9
6.3
7.2
2.6
5.0
5.9
1.3
3.7
4.6
0.1
2.4
3.3
500
236
4.0
6.1
7.0
3.0
5.1
5.9
1.9
4.0
4.9
0.9
3.0
3.8
-
1.9
2.7
450
212
3.0
4.9
5.6
2.1
4.0
4.8
1.3
3.2
3.9
0.4
2.3
3.1
-
1.5
2.2
400
189
2.2
3.9
4.6
1.5
3.2
3.9
0.9
2.5
3.2
0.2
1.9
2.5
-
1.2
1.8
600 and 700 CFM UNIT
Supply Air
Supply Air
(cfm)
(L/s)
NOTE:
The data does not reflect a reduction in ef
fectiveness due to frosting. Based on the
standard air at: 1.2 Kg/m
3
and Cp = 1.0 KJ/Kg°C
13.35 lb/ft
3
and Cp = .24 Btu/lbm°F
Appendix G
Make-up Heat Requirements
1200 cfm 600 cfm and 700 cfm