MACH® Series
Gas-Fired Boiler
Installation
12
3.5.1.2
Venting Materials for Flue/Exhaust Systems
MACH
®
Series boilers are Category IV appliances, which vent with a positive exhaust pressure and with a
temperature that is likely to cause condensation in the vent. Therefore, any venting system used with the MACH
®
Series boiler must comply with the requirements for Category IV venting systems as specified in the latest edition of
NFPA 54/ANSI Z223.1 in the US or the latest edition of CAN/CSA B-149.1 in Canada.
The venting materials listed below are intended for the venting of gas burning appliances
only. Do not use these venting materials for venting liquid or solid fuel (such as oil, kerosene, wood or coal)
appliances
Maintain clearances to combustibles as listed in the vent manufacturer’s installation instructions or as set forth in
the codes and standards listed in this section.
Do not use these vent pipes for incinerators of any sort.
This boiler is not certified for use with PVC nor CPVC venting. Use of PVC or CPVC vent
may result in vent failure and possible serious injury or death.
Table of Acceptable Materials for Venting Systems
Manufactured Venting
US and Canada
Factory Fabricated Metallic Vent Systems listed and labeled to UL1738 (Titled:
Venting Systems for Gas-
Burning Appliances, Categories II, III, and IV)
Table of Applicable Vent Materials
Model
AL29-4C
316L SS
CPVC or PVC
US C2500
X
X
No
CAN C2500
X
X
No
3.5.2 Combustion
Air
Combustion air must be free from dust, lint, etc. The presence of such materials in the air supplied to the burner
could cause nuisance "Low Air" shutdowns or premature burner failure. The boiler should not be operated during
construction while the possibility of drywall dust, demolition dust, etc. exists.
The combustion air supply must be completely free of chemical fumes which may be corrosive when burned in the
boiler. Common chemicals which must be avoided are fluorocarbons and other halogenated compounds, most
commonly present as refrigerants or solvents, such as freon, trichlorethylene, perchlorethylene, chlorine, etc. These
chemicals, when burned, form acids which quickly attack the boiler and the boiler stack. The result is improper
combustion and premature boiler failure.
Under no circumstances shall the boiler room ever be under a negative pressure.
Particular care should be taken when exhaust fans, compressors, air-handling units or other equipment may rob air
from the boiler. Note that this equipment might be in rooms other than the boiler room.
3.5.2.1
Air Inlet Requirements – United States (NFPA 54/ANSI Z223.1 & NFPA/ANSI 211)
When air is supplied from inside the building, the total required volume shall be the sum of the required volume for all
the appliances located in the mechanical room. Adjacent rooms furnished with fixed openings communicating directly
with the mechanical room are considered part of the required volume. The minimum volume is 50 ft
3
per 1000 Btu/hr
(4.8 m
3
/kW) of installed appliance input capacity.
