Specification Sheet
Table Of Contents
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
= Specied airow
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 specications 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