Restrictors And Vent Arrangement - ORTAL 40 Series Installation And Operation Manual

SCENARIO C
The first 90˚ elbow is not taken into calculation of the (H) length for the
restrictor plate size. For example:
Total height of duct work = 15 feet (V)
Length between the center of the 90˚ elbow and wall termination cap = (B)
= 11 feet
The (H) calculation is (H) = (B) = 11. Therefore, the restrictor plate size is
1.18", per the table.
The value of 11 does not appear on the x scale of the table. The choices are
then 9 and 12. Always choose the next higher value, which is also the
smaller restrictor if there is a difference between the values provided.
SCENARIO D
There are no 90˚ elbows or 45˚ angles. The venting is a straight vertical
run. For example:
Total height of duct work = 24 feet (V)
The (H) calculation is = 0. Therefore, the restrictor plate size is 1.97".

Restrictors and Vent Arrangement

The information and tables in this section will help you calculate the correct restrictor selection. The tables below
show the options permitted for both vertical and horizontal positioning of the pipe and the required restrictor. Any
venting pathway that does not appear in the tables requires approval from the manufacturer.
The tables below apply to both Natural Gas and Propane. The tables represent manufacturer's guidelines.
Environment gas type (NG vs. LP and the source of the gas) and other factors may affect the best restrictor choice.
The following symbols are used in the tables:
X: The path is not allowed.
0: There is no restriction.
Numbers other than zero: The number represents the width recommended for the size of restrictor.
NOTE: Space Creator models may require special restrictors. Traditional models do not require restrictors.
REMINDER:
Series 40-170: A minimum 3' vertical run is required before any offset.
Series 200-250: A minimum 6' vertical run is required before any 90˚ bends.
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