Installation Instructions

PAGE D20
SUBJECT TO CHANGE WITHOUT NOTICE - 04/17
ATTIC VENTILATION
Gabled Roof Pyramidal Roof
To determine the proper XFS Fan for your applications, use the following formula.
Number of cubic feet in room / Number of minutes per air change = Required CFM Capacity
EXAMPLE: A general office, (see chart) which requires an air change every ten minutes, would
require the following fan capacity.
If office is 100’ x 40’ x 10’ = 40,000 cubic ft; 40,000 cubic ft / 10 minutes per air change = 4000
Required CFM
From the chart, you would select a fan that is rated at 4000 CFM at 1/8” S.P. (Static Pressure)
Assembly Hall 7 Church 15
Foundry 4
Pressing Room
1
Attic 2 Classroom 6 Garage
5
Projection Booth
2
Auditorium 10 Dance Hall 5 General Office
10
Summer Cooling
1
Barber Shop 6 Department S
tore 6 Gymnasium
8
Toilet
3
Basement 8 Dry Cleaning 5 Laundry
2 Transformer Room
1
Battery Room 4
Engine Room 6
Locker Room
3
Warehouse
12
Boiler Room 1 Factory 6 Machine Shop
8
Weldi
ng Shop
2
Bowling Alley 5 Forge Room 3 Plating Room
3
Application
Minutes per
Air Change
Application
Minutes per
Air Change
Application Application
Minutes per
Air Change
Minutes per
Air Change
WALL MOUNT FANS
XFS SERIES
EXHAUST SHUTTER FANS
Recommended air changes in an attic are about 2-3 minutes per air charge (MIN/AC) to keep the temperatures down. (2 minutes in southern
climates and 3 minutes in northern climates.)
Using 2 minutes, required exhaust CFM =
This provides your required CFM of the exhaust fan, BUT there must be enough venting to supply fresh air to the attic space. A good rule of
thumb is 1.5 ft
2
for every 1000 CFM of airflow.
= 3000 CFM
= 2000 CFM
H
W
H
W
L
L
Volume = L
.
x W x 1/2 H Volume = L x W x 1/3 H
CAUTION!
Attic temperatures can get very high and exceed the high temperature protection device, shutting down the fan if there is not
enough air change to keep the attic at a temperature below 120 °F.
Total Volume
2 MIN/AC
6000 ft
3
2
6000 ft
3
3
1.5
1000
= 3000 x = 4.5 ft
2
1.5
1000
= 2000 x = 3 ft
2
Example:
Use XFS20
Use XFS16
Minnesota
Texas
Texas inlet opening
Minnesota inlet opening