Pentair MT Sizes 500 important safety instructions Venting

MegaTherm Commercial Pool Heating Boiler Page 5

Figure 4. Typical Boiler Installation on Roof Using 4x4 Stringer.

Water

Heater

CLOSET INSTALLATION			ROOM INSTALLATION
	(UNACCEPTABLE)		(ACCEPTABLE)
A closet is any 4 sided enclosure		A room is any enclosure which is at
which is less than 16* times the total		least 16* times greater than the total
volume of all the gas fired appliances		volume of all the gas fired appliances
within the enclosure.		within the enclosure.

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.

	ALCOVE INSTALLATION
	(ACCEPTABLE)
	An alcove suitable for the installation
Water
	of a water heater is a restricted section
Heater	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.

*When the ceiling height exceeds 8 feet, you are only allowed to consider 8 feet when calculating the total volume of the enclosure.

Figure 6. Alcove Installation.

2.2.2 Venting

The MegaTherm boiler has a built-in draft

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.

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 flue 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 qualified engineers.

In Canada: follow Canadian standard, CSA-B149.1 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 boiler, a suitable switch or interlock must be wired into the heater control circuit to prevent the heater from firing unless the blower is operating.

The boiler must be completely isolated and protected from any source of corrosive chemical fumes such as trichlorethylene, perchloroethylene, chlorine, etc.

diverter for natural draft operation and must not be connected to any portion of a mechanical draft system under positive pressure. The flue 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 boiler drafthood. The weight of the stack must not rest on the boiler. The drafthood and boiler top must be easily removable for normal boiler 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 direction of flow. A vent connector should be supported for the design and weight of the material used to maintain clearances and prevent physical damage and separation of joints.

Avoid terminating boiler vents near air conditioning or air supply fans. The fans can pick up exhausted flue products from the boiler and return them inside the building creating a possible health hazard. A minimum of 4 feet (1.2m), in Canada 6 feet (1.8m), horizontal distance must be maintained from electrical meters, gas meters, and relief equipment.