LAARS Mighty Therm AP (Sizes 500-1825) - Installation, Operation and Maintenance Instructions - Manual (Page 5)

Mighty Therm Commercial Pool Heating Boiler Page 5
Figure 4 - Typical Heater Installation on Roof
Using 4x4 Stringer
Figure 5 - Installation on Concrete Blocks or Tile
b. Forced-Air Ventilation
In the United States: any equipment which exhausts air
from the boiler room can deplete the combustion air
supply or reverse the natural draft action of the venting
system. This could cause fl ue products to accumulate
in the boiler room. Additional air must be supplied to
compensate for such exhaust. The information in Table
2 is not applicable in installations where exhaust fans or
blowers of any type are used. Such installations must be
designed by qualifi ed engineers.
In Canada: follow Canadian standard, CSA B149 or local
codes.
If a blower or fan is used to supply air to the boiler room,
the installer should make sure it does not create drafts
which could cause nuisance shutdowns of the pilot. If a
blower is necessary to provide adequate combustion air
to the heater, a suitable switch or interlock must be wired
into the heater control circuit to prevent the heater from
fi ring unless the blower is operating.
The heater must be completely isolated and protected
from any source of corrosive chemical fumes such as
trichlorethylene, perchloroethylene, chlorine, etc.
WARNING
Chemicals stored in the equipment room may
cause corrosion. Sodium hypochlorite feeders,
vented tablet containers, pellet salt and other
chemicals may off-gas into the air in the room
and be drawn into the combustion and dilution
air, corroding the pool heater's metallic parts.
Corrosion damage is not covered under the
limited warranty.
2.2.2 Venting
Laars heaters have built-in draft diverters for natural draft
operation and must not be connected to any portion of a
mechanical draft system under positive pressure. The fl ue
outlet must be connected to a clear, unobstructed vent of
adequate capacity ending above the highest point of the
building with an approved vent cap. The venting system
should be installed according to the latest edition of
ANSI Z223.1 and/or, in Canada, CSA B149 and any local
codes having jurisdiction.
Do not weld or fasten the vent pipe to the heater
drafthood. The weight of the stack must not rest on the
heater. The drafthood and heater top must be easily
removable for normal heater service and inspection.
IMPORTANT NOTE: Do not use sheet metal screws at
the snap lock joints of Type B gas vents.
Avoid using long horizontal runs of the vent pipe, and too
many 90° elbows, reductions or restrictions. Horizontal
runs should have at least a 1/4" (6mm) rise per foot in the
Figure 6 - Alcove Installation
Base must extend out
min. 12" (305mm) on
all sides of
heater frame.
20 ga. min.
galvanized sheet
metal
under entire
heater.
Concrete blocks or tile min. 7" (178mm)
high with 3" (76mm) min. air openings.
Blocks must provide solid base and be braced so they
cannot slip out of place. Air openings in blocks must be
arranged to provide unobstructed opening through entire
width or length of base.
* When the ceiling height exceeds 8 feet, you are only allowed to consider 8
feet when calculating the total volume of the enclosure.
Water
Heater
CLOSET INSTALLATION
(UNACCEPTABLE)
A closet is any 4 sided enclosure
which is less than 16* times the total
volume of all the gas fired appliances
within the enclosure.
ROOM INSTALLATION
(ACCEPTABLE)
A room is any enclosure which is at
least 16* times greater than the total
volume of all the gas fired appliances
within the enclosure.
Water
Heater
ALCOVE INSTALLATION
(ACCEPTABLE)
An alcove suitable for the installation
of a water heater is a restricted section
of a room not separated from the
room by a door or partition and which
meets the minimum clearances for
the specific model water heater listed
below.