P
AGE
14
I
NSTALLATION
(C
ONT
.)
Elbows
•
Do not use 45° elbows.
•
Elbows are considered either horizontal or vertical (see the illustration below). Only one horizontal
elbow may be used on the vent system. Horizontal elbows do not add to the vent length when
determining the acceptable vent configuration.
•
A maximum of two vertical elbows may be used.
•
Snorkel terminations are considered a vertical elbow. The snorkel rise (either 36" or 14") is figured
into the calculation when determing the acceptable vent configuration.
How to Measure Vent Lengths
•
Measurements for determining the acceptable vent configuration are taken by section length (not
from center to center).
•
Elbow sections do not figure into the calculation when determining the acceptable vent
configuration.
+
Elbows add 3" to the length of the vent system when calculating where the vent will penetrate a wall
or ceiling or when calculating clearances.
