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13 - vertical termination - two pipes, 10 - installation - vent and combustion air, 1 - determine location – Slant/Fin VSL-160C Part B User Manual

Page 16: 2 - prepare roof penetrations, 3 - termination and fi ttings, Warning

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10.13 - Vertical
termination - Two
pipes

WARNING!!!

Follow

instructions below when
determining vent location to
avoid possibility of severe
personal injury, death or
substantial property damage.

WARNING!!!

Do not

connect any oher appliance
to the vent pipe or multiple
boilers to a common vent
pipe. Failure to comply could
result in severe personal injury,
death, or substantial property
damage.

Installation must comply with local
requirements and with the National
Fuel Gas Code, ANSI Z223.1 for
U.S. installations or CSA B149.1 for
Canadian installations.

10 - INSTALLATION - Vent and combustion air

Figure 10-23 Two pipes vertical terminations
of air and vent

Vent

Screen

above roof or
snow line

Combustion
air intake

above air

inlet and

above roof

or snow

line

Alternate air
intake location:
air intake
terminal may
be located
anywhere within
24” of vent
terminal

10.13.1 - Determine
location

Locate the vent/air terminations using
the following guidelines:
1. The total length of piping for vent or

air must not exceed the limits given
in the Section 10-4.

2. The vent must terminate at least

3 feet above the highest place in
which the vent penetrates the roof
and at least 2 feet above any part
of a building within 10 horizontal
feet.

3. The air piping must terminate in a

down-turned 180° return pipe no
further than 2 feet from the center
of the vent pipe. This placement
avoids recirculation of fl ue products
into the combustion air stream.

4. The vent piping must terminate at

least 1 foot above the air intake.
The air inlet pipe and vent pipe can
be located in any desired position
on the roof, but must always be no
further than 2 feet apart and with
the vent termination at least 1 foot
above the air intake.

5. Locate terminations so they are

not likely to be damaged by foreign
objects, such as stones or balls,
or subject to buildup of leaves or
sediment.

10.13.2 - Prepare roof
penetrations

1. Air pipe penetration: cut a hole for

the air pipe. Size the air pipe hole
as close as desired to the air pipe
outside diameter.

2. Vent pipe penetration:

a. Cut a hole for the vent pipe.

For either combustible or
noncombustible construction,
size the vent pipe hole with at
least a 1/2 inch clearance around
the vent pipe outer diameter: 4
inch hole for 3 inch vent pipe

b. Insert a galvanized metal thimble

in the vent pipe hole.

3. Space the air and vent holes to

provide the minimum spacing
shown in Figure 10-23 and listed in
section 10.13.1.

4. Follow all local codes for isolation

of vent pipe when passing through
fl oors, ceilings, and roofs.

5. Provide fl ashing and sealing boots

sized for the vent pipe and air pipe.

10.13.3 - Termination and
fi ttings

1. Prepare the vent termination and

the air termination elbow (Figure
10-23) by inserting bird screens.

2. The air piping must terminate in a

down-turned 180° return bend as
shown in Figure 10-23. Locate the
air inlet pipe no further than 2 feet
from the center of the vent pipe.
This placement avoids recirculation
of fl ue products into the combustion
air stream.

3. Maintain the required dimensions

of the fi nished termination piping as
shown in Figure 10-23.

4. Do not extend exposed vent pipe

outside of building more than
shown in Figure 10-23. Condensate
could freeze and block vent pipe.