MACH
®
Gas Fired Boiler
18
3.5.3.3
CATEGORY IV INSTALLATIONS
If the vent installation is designed for Category IV conditions only (condensing – positive pressure) as it is defined in
ANSI Z21.13/CSA 4.9, latest edition. The vent material must be as listed in Table in section 3.5.1.2 and can be run
horizontally 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.
3.5.3.4
CPVC VENT SYSTEM INSTALLATION
Install CPVC vent systems in accordance with this manual and the SMACNA
Thermoplastic Duct Construction
Manual.
Install manufactured vent systems in accordance with the manufacturer’s listing and instructions.
When venting this boiler using CPVC vent material, the following operating and installation conditions must be met:
Operating Parameters
Maximum Water Temperature Set Point 180°F
•
Flue Gas Limit 200°F
Installation Parameters
Do not use a barometric damper
if operating with a positive stack
pressure (Category IV). Harmful flue gases may leak into the room which can cause serious
injury or death.
Use caution if installing a barometric damper in the exhaust vent. The
vent pressure
must be negative
(Category II) from the barometric to the vent termination at
all times to prevent leakage of harmful flue gases into the room. Leakage of flue gases can
cause serious injury or death.