Enviro GAS 828 BV. INS. - Manual (Page 12)

For best venting performance, we recommend total
vent height of 10ft (3m) to 30ft (9m). Total
horizontal length depends on the number of elbows
used. The venting should never slope down. 1/4"
rise per 2' horizontal is recommended.
If practical, it is best have shorter horizontals and
fewer elbows.
-Two 90° elbow, maximum total horizontal length of 20ft (6m).
-Three 90° elbow, maximum total horizontal length of 13ft (3.8m).
-Four 90° elbow, maximum total horizontal length of 6ft (1.9m).
-Five 90° elbow, maximum total horizontal length of 0ft (0m). If 45° elbows are used, one 90° elbow is equivalent
to two 45° elbows.
Venting rise should be a minimum of 3 ft (.62m).
from the top of the unit before any horizontal.
For other special venting requirements, please refer
to the local, state/provincial or national codes.
The bottom of the vent cap shall extend at least 2ft.
(.6m) above the highest point of the roof where it
passes through and at least 2ft (.6m) higher than
any portion of the roof within a horizontal distance
of 10ft. (3m). See Figure 14.
Height above roof
surface within 10 ft
horizontally
Figure 14
9. AIR SHUTTER ADJUSTMENT
• There is a separate venturi air shutter for each burner
• The venturis have been set for installation at sea level
• To adjust for high altitude: Remove the front cover plate, loosen the 2 set screws with a long screwdriver
and rotate the air shutters to the correct setting.
Figure 15
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