Operating instructions

Part number 550-141-887/0800
7
AHE Series 4 Direct Vent Wall-Mounted Boilers — Boiler Manual
1d
Prepare boiler location — air openings
Combustion air
Combustion air must be ducted directly from outside
to the AHE boiler air intake fitting. This method is
defined as “direct vent” (also referred to as “sealed
combustion”). Refer to Section 2, page 8, in this manual
for venting instructions. Two options are available: side
venting and back venting.
Sizing air/ventilation openings
Provide openings in the boiler enclosure as described
below. Air is required for ventilation to prevent
overheating of boiler controls and boiler space. Air is
also required for combustion of other appliances if
located in the same space with an AHE boiler.
Provide adequate openings for
ventilation and combustion air as
required by the National Fuel Gas
Code to ensure proper combustion
and operation and to reduce the risk
of severe personal injury, death or
substantial property damage due to
insufficient air.
AHE with no other appliances in same
space
No special air/ventilation openings are required for AHE
installations provided the space is at least:
• 2,250 cubic feet total volume for AHE-45 or
• 3,000 cubic feet total volume for AHE-60.
For installations in spaces smaller than above (closet,
for example), provide two openings for ventilation air.
Each opening must be at least:
• 45 square inches for the AHE-45 or
• 60 square inches for the AHE-60.
Place one opening within 3 inches of the top of the
boiler, the other opening within 3 inches of the bottom
of the boiler.
AHE sharing space with other
appliances
Unless the space has a total volume of no less than 50
cubic feet for each 1,000 Btuh of total input of all
appliances:
1. Provide two openings into the space, each opening
providing at least 1 square inch free area per 1,000
Btuh of all appliances in the space. Locate one
opening within 12 inches of the ceiling, the other
opening within 12 inches of the floor.
2. For larger spaces (over 50 cubic feet total volume
per 1,000 Btuh of all appliances), no additional air
openings are required unless the space is
categorized as of “tight construction” as defined
below.
Tight construction
ANSI Z223.1 defines unusually tight construction
where:
a. Walls and ceilings exposed to the outside
atmosphere have a continuous water vapor retarder
with a rating of 1 perm or less with openings
gasketed, and...
b. Weather-stripping has been added on openable
windows and doors, and...
c. Caulking or sealants are applied to areas such as
joints around windows and door frames, between
sole plates and floors, between wall-ceiling joints,
between wall panels, at penetrations for plumbing,
electrical, and gas lines, and in other openings.
For tight construction installations:
1. Provide two openings into the space, each opening
providing at least 1 square inch free area per 1,000
Btuh of all appliances in the space. Locate one
opening within 12 inches of the ceiling, the other
opening within 12 inches of the floor.
Louver allowance
The free area of openings means the area after reduction
for any installed louvers or grilles
. Be sure to consider
this reduction when sizing the air openings.
Exhaust fans and air movers
The appliance space must never be under a negative
pressure unless all appliances are installed as direct vent.
Always provide air openings sized not only to the
dimensions required for the firing rate of all appliances,
but also to handle the air movement rate of the exhaust
fans or air movers using air from the building or space.