Weil-McLain 550 MBH Nstallation And Operation Manual page 27

®
SlimFit Series 3
Direct Exhaust
DIRECT EXHAUST vertical termination
DIRECT EXHAUST — Vertical termination
— installation sequence overview
Install the boiler.
Determine the proper location for wall penetration for each
termination.
Prepare roof penetrations before installing vent piping.
Finish by attaching external pipe and fittings as shown in the
termination instructions.
Install terminations as described in this manual.
Support vertical runs on the outside of the building with
brackets as shown in the termination instructions.
Install vent piping from boiler to termination.
Install a hanger support within 6 inches of any upturn in
the piping.
Install pipe supports every 5 feet on both the horizontal and
vertical runs.
Slope horizontal piping downward toward the boiler at least
1/4 inch per foot.
Connect the vent piping at the boiler per manual instruc-
tions.
Part number 550-100-168/0516
COMMERCIAL CONDENSING GAS
—
-
FIRED WATER BOILER
Determine location for vertical
termination
1. Locate the vent termination using the following guide-
lines:
2. The vent piping must terminate in a coupling as shown
in Figure 15, page 28.
3. Consider the surroundings when terminating the vent:
a. Position the vent termination where vapors will not
damage nearby shrubs, plants or air conditioning
equipment or be objectionable.
b. The flue products will form a noticeable plume as
they condense in cold air. Avoid areas where the
plume could obstruct window views.
c. Prevailing winds could cause freezing of condensate
and water/ice buildup where flue products impinge
on building surfaces or plants.
d. Avoid possibility of accidental contact of flue prod-
ucts with people or pets.
e. Do not locate the termination where wind eddies
could affect performance or cause recirculation,
such as inside building corners, near adjacent build-
ings or surfaces, window wells, stairwells, alcoves,
courtyards or other recessed areas.
f. Locate or guard vent to prevent condensate damage
to exterior finishes.
4. Maintain clearances as shown in the illustrations in this
manual section. Also maintain the following:
a. Vent must terminate:
At least 12 inches above roof or snow line as
shown in Figure 15, page 28.
At least 6 feet from adjacent walls.
No closer than 5 feet below roof overhang.
At lease 3 feet above any forced air intake within
10 feet.
No closer than 48 inches below or horizontally
from any door or window or any other gravity
air inlet.
b. Do not terminate closer than 4 feet horizontally
from any electric meter, gas meter, regulator, relief
valve or other equipment.
5. Where the vent penetrates the roof, the annular space
around the penetration must be permanently sealed
using approved materials to prevent entry of combus-
tion products into the building.
6. 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.
7. Do not connect any other appliance to the vent pipe.
Prepare roof penetration
1. Vent pipe penetration:
a. Cut a hole for the vent pipe. For either combustible or
noncombustible construction, size the vent pipe hole
at least 0.5" larger than the vent pipe diameter – use a
7" hole for 6" PVC or PP.
b. Insert a galvanized metal thimble in the vent pipe
hole.
2. Follow all local codes for isolation of vent pipe when
passing through floors, ceilings and roofs.
3. Provide flashing and sealing boots sized for the vent
pipe and air pipe.
Boiler Manual
27