Patterson-Kelley DVSCM-02 - Manual (Page 9)

Thermific ® Gas-Fired Boiler Installation
Page 7
Whichever termination is chosen, it must be double
wall vent certified under UL 1738, or ULC-636.
When installing a sidewall exhaust system the
termination must be backed by a metal plate secured to
the wall as shown in the figure.
Correct rain cap,
unrestricted.
Typical incorrect
rain cap.
If the exhaust vent is routed through the roof, the
termination must be either the same type as described
for a sidewall installation or a rain cap. The preferred
method to terminate the exhaust vent is with a rain cap
to minimize the drippage of condensate onto the roof
and ice build-up
. The rain cap should be an
unrestrictive type similar to the figure above. Elbows
are also acceptable.
3.4.5 Equivalent Length of Fittings
Fitting Description Equivalent Length
90º Elbow 10 feet
45º Elbow 5 feet
Rain Cap 10 feet
Boot Tee/135º Tee 10 feet
Standard Tee Used as a
Vent Termination 10 feet
3.4 C LEARANCES
In addition to any clearance requirements in Sections
3.1 and 3.3 the following clearances must be
maintained for inlet and vent components.
3.4.1 Sidewall Installations
Combustion
Air Intake
2' to snow
line
Flue Gas
Outlet
Flue Gas
Outlet