Raypak 850, 300 operating instructions Water Piping, Canadian Installations, General

b. Where communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of 1 in.2 per 2,000 BTUH (1,100 mm2 per kW) of total input rat- ing of all equipment in the enclosure.

2.One permanent opening, commencing within 12 in. (305 mm) of the top of the enclosure, shall be permitted where the equipment has clearances of at least 1 in. (25 mm) from the sides and back and 6 in. (152 mm) from the front of the appliance. The opening shall directly communicate with the out- doors or shall communicate through a vertical or horizontal duct to the outdoors or spaces that freely communicate with the outdoors, and shall have a minimum free area of:

a.1 in.2 per 3,000 BTUH (740 mm2 per kW) of the total input rating of all equipment located in the enclosure, and

b.Not less than the sum of the areas of all vent connectors in the confined space.

WARNING: Do not use the “one permanent opening” method if the equipment room is under negative pressure conditions.

Canadian Installations

CAUTION: All combustion air must be drawn from the air outside of the building; the mechanical equip- ment room must communicate directly with the outdoors.

1.Ventilation of the space occupied by the heater shall be provided by an opening(s) for ventilation air at the highest practical point communicating with the outdoors. The total cross-sectional area of such an opening(s) shall be at least 10% of the area required in 2. and 3. (below), but in no case shall the cross-sectional area be less than 10 in.2 (65 cm2).

2.For heaters using a barometric damper in the vent system, there shall be a permanent air supply opening(s) having a cross section area of not less than 1 in.2 per 7,000 BTUH (320 mm2 per kW) up to and including 1 million BTUH, plus 1 in.2 per 14,000 BTUH (160 mm2 per kW) in excess of 1 million BTUH. This opening(s) shall be either located at or ducted to a point not more than 18 in. (450 mm) nor less than 6 in. (152 mm) above the floor level. The duct can also “goose neck” through the roof. The duct is preferred to be straight down 12

and terminated 18 in. (450 mm) from the floor, but not near piping. This air supply opening require- ment shall be in addition to the air opening for ventilation air required in 1. (above).

WARNING: Care must be taken to ensure that the equipment room is not under negative pressure conditions.

3.For heaters when air supply is provided by natural air flow from outdoors for a power burner and there is no draft regulator, drafthood or similar flue gas dilution device installed in the same space, in addition to the opening for ventilation air required in 1., there shall be a permanent air supply open- ing(s) having a total cross-sectional area of not less than 1 in.2 for each 30,000 BTUH (74 mm2 per kW) of total rated input of the burner(s), and the location of the opening(s) shall not interfere with the intended purpose of the opening(s) for ventila- tion air referred to in 1. This opening(s) can be ducted to a point not more than 18 in. (450 mm) nor less than 6 in. (152 mm) above the floor level. The duct can also “goose neck” through the roof. The duct is preferred to be straight down 18 in. (450 mm) from the floor, but not near piping.

4.Refer to the B149 Installation Code for additional information.

Water Piping

General

The heater should be located so that any water leaks will not cause damage to the adjacent area or struc- tures.

CAUTION: This boiler requires forced water circulation when the burner is operating. See Table G and Table H for minimum and maximum flow rates and water pump selection. The pump must be interlocked with the boiler to prevent heater operation without water circulation.

NOTE: Minimum pipe size for in/out connections is 1-1/2” NPT for model 300 and 2” NPT for models 500 and 850. Verify proper flow rates and ∆T as instruct- ed in this manual.