Harsco Industrial 1004905923 Installation & Owner's Manual page 16

NOTICE!
1. The free area of a combustion air supply opening is calculated by deducting the blockage area of any fixed
louvers, grilles or screens from the total area of the opening.
2. Screens shall be not smaller than ¼"
3. Motorized louvers shall be interlocked with the appliance so that they are proven open prior to main burner
ignition and operation
Table of Canadian Minimum Area of Combustion and Ventilation Air Openings
MFD
Model # Input (Btu/Hr)
N2500 2,500,000
N3000 3,000,000
3.5.3 Flue Venting
This boiler is not certified for use with Type "B" vent nor with any type of plastic venting.
This boiler is a Category IV appliance (condensing – positive pressure) as it is defined in ANSI Z21.13/CSA 4.9,
latest edition. The vent material must be as described in section 3.5.1.2. The exhaust vent can be run horizontal-
ly or vertically.
Vent installations shall be in accordance with NFPA54/ANSI Z223.1, the National Fuel Gas Code, or CAN/CSA-
B149.1, the Natural Gas and Propane Installation Code, or applicable provisions of the local building codes.
3.5.3.1 VENT SIZING
The vent must be sized in accordance with the ASHRAE Systems and Equipment handbook, Chapter 30 or ac-
cording to the vent manufacturer's recommendations. When using manufactured venting systems, consult your
vent supplier for correct sizing and structural support requirements.
MFD Model
N2500/N3000
The vent must be sized according to the vent manufacturer's recommendations. Consult your vent supplier
for correct sizing and structural support requirements. Design calculations should be based on a positive
pressure at the flue collar, not to exceed 1.0 inch W.C. with a stack temperature of 300° F (gross) and a CO
level of 8.5% natural gas. The vent should be designed to provide positive pressure at the flue collar at all firing
rates.
NOTICE! Refer to example in section 3.5.5 regarding pressure drop across the boiler.
tem. Flue gases may leak into the room.
Required Combustion Air Opening
2
in
83.3
100
Table of Vent Design Parameters
Frictional
Resistance Temperature
1.0" Max 300°F (gross)
Do not use a barometric damper with this boiler. This is a positive pressure sys-
This equipment MUST NOT be used with a heat actuated automatic vent damper.
®
MODU-FIRE Forced Draft Gas-Fired Boiler 2500-3000
2
mm
53,763
64,516
Stack
CO Natural Gas
2
8.5%
16
Ventilation Air Opening
2 2
in mm
10 6,452
10 6,452
CO LP Gas
2
10.3%
2