Specification Sheet

451
GRAVITY VENTILATORS SIZING
Sizing
The tables shown offer quick selections at common static pressure points. Selection choices vary
widely due to eld conditions and size choices. The following formulas are useful in making selections:
(A) Throat Area =
(B) Throat Velocity =
(C) Velocity Pressure =
(D) Determine new static pressure when CFM is known:
SP
2
= SP
1
x
CFM
2
= Specied airow
CFM
1
= Known CFM from table selection
SP
2
= Static pressure to be determined
SP
1
= Static pressure in table corresponding to CFM
(Ex.) Determine new unknown CFM when static pressure is known:
CFM
2
= CFM
1
x
CFM
2
= Unknown
CFM
1
= Catalog CFM
SP
2
= New static pressure where CFM is unknown
SP
1
= Known static pressure from known CFM (CFM
1
)
CFM
Velocity
CFM
Throat Area
Throat Velocity
4005
CFM
2
CFM
1
SP
2
SP
1
[
[
[
[
2
[
[
2
All specications are subject to change without notice unless approved in submittal by S&P USA.
BGH
RLX
RCXII (sizes 24-36)
RCXII (sizes 6-20)
RCXII-SF