Vertical Termination Venting Diagram - Straight Vertical; Vent Restrictor Sizing Guidelines - ORTAL 40 Series Installation And Operation Manual

Vertical Termination Venting Diagram – Straight Vertical
Series 40-250
V minimum = 3 feet
Vertical (V)
42 ft
NOTE: For venting runs that exceed this maximum, consider Ortal's Power Vent System. See the Ortal Power
Vent Manual for details.

Vent Restrictor Sizing Guidelines

SCENARIO A
When you have vertical elbows of 45˚, no additional length for the (H)
calculation for the restrictor plate size is needed. For example:
Total height of duct work = 6 feet (V)
Length between the center of the two 45˚ elbows = (B) = 3 feet
The (H) calculation is (H) = (B) so the restrictor plate size is 1.97", per the table.
SCENARIO B
If there are two 90˚ elbows in the vent system, an additional 6 feet must be
added to the (H) calculation for the restrictor plate size. For example:
Total height of duct work = 18 feet (V)
Length between the center of two 90˚ elbows = (B) = 21 feet
The (H) calculation to be used in the restrictor table is (H) = (B) +6 feet, so the
(H) length is 27 feet.
Per the table, the restrictor plate is 0. No restrictor is required.
Ortal Installation Manual: Built-in Models, December 2019 (V2) 59