Air Openings - Weil-McLain Ultra Commercial Installation And Start-Up Manual

COMMERCIAL GAS
DIRECT EXHAUST — Boiler room air openings
MINIMUM combustion air openings for direct exhaust applications —

Air openings

The required air opening sizes below are FREE AREA,
after reduction for louver obstruction. Note the ex-
ception below for large spaces.
Part number 550-100-086/0809
-
FIRED WATER BOILER
appliances in room
1
square inch per
of all appliances in the room
1 square inch per
of all appliances in the room
opening **, each at least:
1 square inch per
of all appliances in the room
1 square inch per
of all appliances in the room
opening **, each at least:
1
square inch per
of all appliances in the room
1
square inch per
of all appliances in the room
opening **, each at least:
1
square inch per
of all appliances in the room
A single combustion air opening can be used for cases ,
provided that:
The single opening must communicate directly to the outdoors or to a space that
communicates directly with outdoors (NOT to an interior space).
The top of the opening must be within 12 inches of the ceiling.
The free area of the opening must be at least equal to the sum of the areas of all
equipment vent connectors in the space.
NO combustion air openings are needed when the boiler (and other appliances) are installed
in a space with a volume NO LESS than 50 cubic feet per 1,000 Btuh of all appliances in
the space. That is, total the input of all appliances in MBH (1,000's of Btuh), then multiply
this total times 50. The building MUST NOT be of tight construction.
Example: For a total input of 1500 MBH (1,500,000 Btuh) and an 8-foot ceiling height,
the minimum volume would be 50 x 1500 x 8 = 60,000 cubic feet.
— Boiler Manual
Ultra boiler
WITH other
openings, each at least:
1
Btuh
openings, each at least:
4 Btuh
— OR —
3 Btuh
openings, each at least:
2 Btuh
— OR —
3
Btuh
openings, each at least:
4
Btuh
— OR —
3
Btuh
(continued)
Ultra boiler
WITHOUT other
appliances in room
openings, each at least:
1 4
square inch per Btuh
of all appliances in the room
openings, each at least:
1 square inch per 4 Btuh
of all appliances in the room
— OR —
opening **, each at least:
1 square inch per 3 Btuh
of all appliances in the room
openings, each at least:
1 square inch per 4 Btuh
of all appliances in the room
— OR —
opening **, each at least:
1 3
square inch per Btuh
of all appliances in the room
openings, each at least:
1 4
square inch per Btuh
of all appliances in the room
— OR —
opening **, each at least:
1 3
square inch per Btuh
of all appliances in the room
or above, sized as listed,
31