Pentair MT warranty 2B. Installation of Indoor Boilers, 2B-1. Combustion Air Supply

Page 4 Pentair Water Commercial Pool and Spa

All boilers must be installed on a non-combustible floor. Under no circumstances can boilers be installed on carpeting. The National Fuel Code allows a boiler to be placed on other than a non combustible surface when such an installation complies with the local codes. This code specifies the surface under the boiler be protected with hollow masonry no less than 4" thick, covered with sheet metal at least 20 gage in thickness. Such masonry must be laid with ends unsealed, and joints matched in such a way as to provide a free circulation of air from side to side through the masonry (see Figure 2).

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 2. Non-Combustible Base.

2B. Installation of Indoor Boilers

2B-1. Combustion Air Supply

1.The boiler location must provide sufficient air supply for proper combustion, and ventilation of the surrounding area as outlined in the latest edition of ANSI standard Z223.1 or, in Canada CAN1-B149, and any local codes that may be applicable. Inadequate combustion air supply may result in incomplete combustion and consequent sooting of the heat exchange and unsafe operation of the boiler.

2.In general, (in the U.S.), these requirements specify that equipment rooms which represent confined spaces should be provided with two permanent air supply openings communicating directly through the wall to outside air; one within 12 inches of the ceiling, the other within 12 inches of the floor. Each opening should have a minimum free area of one square inch per 4,000 BTUH input of the total input rating of all appliances in the enclosed area. These requirements differ in Canada. Consult the National Standard of Canada CAN1-B149 for details. See Table 2 for recommended air supply for U.S. models. An improperly ventilated equipment room can get excessively hot and

Clearance	Indoor	Outdoor
From	(Inches)	(Inches)
Top	24	—
Water Conn. Side	24	24
Opposite Side	24	24
Front	48	48
Rear	24	24
Vent	6	—

Table 1. Minimum Boiler Clearance

From Combustible Surfaces

cause accelerated deterioration of controls and electrical components.

3.Exhaust Fans or Vents: 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 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.

Indoor	Each Opening*
Size	(Square Inches)
2000	500
2450	613
3050	763
3500	875
4050	1013
4500	1125
5000	1250

Net Free Area in Square Inches*

*Area indicated is for one of two openings: one at floor level and one at the ceiling, so the total net free area would be double the figures indicated. For all other conditions, refer to latest edition of ANSI A223.1.

NOTE: Check with louver manufacturers for Net Free Area of louvers. Correct for screen resistance to the Net Free Area if a screen is installed. Check all local codes applicable to combustion air.

Table 2. Minimum Recommended Air

Supply to Equipment Room.

4.If a blower or fan is used to supply air to the equipment room, the installer should make sure it does not create drafts which could cause nuisance shut-downs of the pilot. If a blower is necessary to provide adequate combustion air to the boiler, a suitable switch or equivalent must be wired into the boiler control circuit to prevent the boiler from firing unless the blower is operating.

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