MACH® Series
Gas-Fired Boiler
Installation
Page 8
•
When rooms are on different floors, each opening
shall have an area equal to 2 square inches for
each 1000 Btu/hr (4400 mm
2
/ kW) of installed
appliance input capacity.
When combustion air is supplied from outside the
building, the boiler room shall be provided with one or
two openings to ensure adequate combustion air and
proper ventilation.
When using one permanent opening, the opening shall
commence within 12 inches of the ceiling and shall
communicate directly with the outdoors or through a
vertical or horizontal duct that communicates to the
outdoors.
Minimum free area of the opening is;
•
1 square inch for each 3000 Btu/hr (700 mm
2
/
kW) of installed appliance input capacity, and
•
not less than the sum of the areas of all vent
connectors in the room.
When using two permanent openings, one opening
shall be less than 12 inches above the floor and the
other less than 12 inches below the ceiling, preferably
on opposite walls. The openings shall communicate
directly, or by way of ducts, with free outdoor air.
Minimum net free area of the openings shall be
calculated in accordance with the following:
•
When air is taken directly from outside the
building, each opening (minimum of two, as
outlined above), 1 square inch for each 4,000 Btu
per hour of total boiler input is required.
•
When air is taken from the outdoors through a
vertical duct, 1 square inch per 4,000 Btu per hour
of total boiler input is required.
•
When air is taken from the outdoors through a
horizontal duct , 1 square inch per 2,000 Btu per
hour of total boiler input is required.
NOTE:
1.
The required size of openings for combustion,
ventilation and dilution air shall be based on the
net free 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.
3.6
F
LUE
V
ENTING
Note: Additional information is contained in the
venting supplement “MACH-07VG”.
Caution!
All boiler venting systems should be designed by
a qualified professional engineer experienced in
venting system design. The information
contained herein should be used as a guide only
and is not intended to be used in lieu of qualified
technical expertise.
This boiler is Category IV (condensing – positive
pressure) as it is defined in ANSI Z21.13/CSA 4.9,
latest edition.
This boiler is not certified for use
with Type "B" vent.
The vent material must be :
•
AL29-4C Stainless Steel Vent Systems
listed and labeled to UL1738 Venting
Systems for Gas-Burning Appliances,
Categories II, III, and IV
•
316L Stainless Steel where certified
and warranted by the vent
manufacturer for venting of Category
IV appliances
Vent installations shall be in accordance with Part 12,
Venting of Equipment
, of the National Fuel Gas Code,
ANSI Z223.1 or Part 8,
Venting Systems and Air
Supply for Appliances
of the Natural Gas and Propane
Installation Code CAN/CSA-B149 current revision,
or applicable provisions of the local building codes.
The vent must be sized in accordance with the
ASHRAE Systems and Equipment handbook,
Chapter 30 or according to the vent manufacturer’s
recommendations. When using manufactured vent
systems; consult your vent supplier for correct sizing
and structural support requirements.
