Weil-McLain WM97+ Aqua Logic, Manual

Page: 20 / 108

Part number 550-142-058/0811
WM97+
gas
-
fired water boiler
— Boiler Manual
20
Figure 17 Combustion and ventilation air openings for WM97+ Direct Vent installations
The WM97+ boiler CANNOT be in the same space with other appliances if clearances around the WM97+ are less
than the recommended service clearances shown in Figure 1, page 7.
Air openings
The required air opening sizes below are FREE AREA,
after reduction for louver obstruction. Note the ex-
ception below for large spaces.
WM97+ boiler
WITH other
appliances in room
WM97+ boiler
WITHOUT other
appliances in room
TWO openings, each at least:
1 square inch per 1,000 Btuh
of all other appliances in the room
(Unless specified otherwise by
appliance manufacturer)
NO openings are required if the
boiler installation provides at least the
recommended service clearances
shown in Figure 1, page 7.
If the space is smaller than Fig-
ure 1, page 7, provide openings
ONLY as shown in Figure 2, page 7
.
Each opening must have a free
area no less than 1 square inch per
1,000 Btuh input of the boiler.
TWO openings, each at least:
1 square inch per 4,000 Btuh
of all other appliances in the room
— OR —
ONE opening **, each at least:
1 square inch per 3,000 Btuh
of all other appliances in the room
(Unless specified otherwise by
appliance manufacturer)
TWO openings, each at least:
1 square inch per 2,000 Btuh
of all other appliances in the room
— OR —
ONE opening **, each at least:
1 square inch per 3,000 Btuh
of all other appliances in the room
(Unless specified otherwise by
appliance manufacturer)
TWO
openings, each at least:
1
square inch per
4,000
Btuh
of all other appliances in the room
— OR —
ONE
opening **, each at least:
1
square inch per
3,000
Btuh
of all other appliances in the room
(Unless specified otherwise by
appliance manufacturer)
** NOTICE:
Requirements for using the SINGLE air opening
option.
A single combustion air opening can be used for cases b, c or d above (WM97+ with
other appliances in room only), sized as listed, 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.
SPECIAL EXCEPTION FOR LARGE SPACES
(WM97+ WITH other appliances in room only):
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 500 MBH (500,000 Btuh), the minimum volume would be
50 x 500 = 25,000 cubic feet (3,125 square feet if ceiling height is 8 feet).
Boiler room air openings