Weil-McLain 80 - Manual (Page 4)

Weil-McLain 80 Boiler For Gas, Light Oil, Gas/Light Oil Fired Burners
4 Part No. 550-141-935/0602
Before installing boiler
(continued)
1
Figure 2 Combustion and ventilation air
openings — Boiler room below grade
Figure 3 Combustion and ventilation air
openings — Boiler room partially or
completely above grade
Provide combustion and ventilation air
openings:
Do not install an exhaust fan in boiler
room. Adequate combustion and
ventilation air must be provided to assure
proper combustion and prevent
possibility of flue gas leakage and carbon
monoxide emissions, causing severe
personal injury or death.
Opening sizes must comply with state, provincial or local
codes. In their absence, use the following when boiler is in
a confined room:
• Provide two permanent openings in boiler room — one
within 12 inches of ceiling, one within 12 inches of floor.
Minimum dimension of each opening is 3 inches.
1. When all air is taken from within building, each
opening should be at least one square inch/1,000
Btuh boiler input and freely connect with areas
having adequate infiltration from outside.
2. When all air is taken from outdoors, each opening
should connect directly or by ducts from outdoors
or crawl or attic spaces that freely connect with
outdoors and sized as listed below:
a. through outside wall or vertical ducts - at least
one square inch/4,000 Btuh boiler input.
b. through horizontal ducts - at least one square
inch/2,000 Btuh boiler input.
c. where ducts are used, they should be same cross-
sectional area as free area of openings they are
connected to.
d. compensate for louver, grille or screen blockage
when calculating free air openings. Refer to their
manufacturer's instructions for size. If
unknown, use:
•
wood louvers - 20-25% free air.
• metal louvers or grilles - 60-75% free air.
• screens - not less than ¼ inch mesh.
Lock louvers in open position, or interlock with equipment
to prove open before boiler operation.
When combustion and ventilation air enters through
sidewall openings, ensure openings comply with Figures 2
and 3.