HOW TO FIGURE

HOW TO FIGURE LIGHT
TRAP SQUARE FOOTAGE

Their are many variables when figuring the square footage for light traps.
Are the traps for a new house or for a retro-fit?
Do the traps have to go directly on the fans, or is a false wall going to be built?
Is a desired air flow required?

Light traps are figured by two methods either by the Total Fan CFM or by the Total House Square Footage.

If a pre determined # of fans are going to be used take the fan CFM @ .10 static pressure and multiply by the # of fans used.

Fan CFM @ .10 SP =
# of fans used =

168,000

Total CFM

Example

To find the total house square footage use
the following fomula.

Total Fan CFM

Total House Square Footage

Center height of house =
Side wall height of house =

19.5 ft

19.5 divided by 2 =

Width of house =
Lenght of house =

156,000

Total house
square footage

Center height plus side wall height, divided by two, multiplyed by the width, and then the lenght of the house.

Example

For a given house design, total trap area needed is obtained by dividing either the total house square footage, or the total fan CFM by the by the listed light trap cfm per sq ft requirement .

For example, if the total house airflow is 156,000 CFM, using our Max-Flow light trap you would require 250 sq ft of light trap for the fan end and 367 sq ft for the inlet end.

Amount of trap needed for fan end.

156,000 divided by 753 = 207 sq ft.

Amount of trap needed for the inlet end.

156,000 divided by 525 = 297 sq ft.