P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 2
KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
The Hydrotherm
KN
boiler — Vent and air piping options
Vent and air piping, general
Pages 2, 3 and 4 are a brief overview of the options for vent and air piping confi gurations. Page 3 and 4
gives a summary and brief list of requirements for each of the vent/air confi guration options.
When air is taken from the boiler room (no air pipe connected to the boiler air inlet fi tt ing), follow the
instructions in the
K N
Boiler manual to ensure the boiler room has proper openings for combustion air
and ventilation.
Vent piping
Category II & IV venting only
Category IV Individual Vent: All
K N
boilers require vent piping listed for use in pressurized,
condensing operation. Use only the materials specifi ed in this manual. Category II Common Vent:
Cosult factory when common venting multiple boilers and/or use an engineered venting system
solution.
Vent pipe options
Use only Heat-fab Saf-T Vent® EZ Seal vent pipe and components. You will fi nd specifi c component
information for each confi guration in this manual.
Vent pipe joint assembly
EZ Seal vent piping use a silicon rubber ring-style gasket in each joint. Joints are secured using metal tabs
that wrap around a ring on the adjacent piping component for Heat-fab vent pipe, or gear clamps for vent
pipe. Never use screws in the vent piping. Screws are only applied to the air piping portion of Heat-fab SC
concentric vent, used for concentric vent/air sidewall terminations.
Air piping
Air options
Combustion air can be piped through the side wall or through the roof of the building. Sidewall air intake
can be done with either through-the-roof or sidewall venting. See the next page for a summary of each
confi guration.
Air piping materials
Th e best choices for air piping are PVC, CPVC or ABS. Th ese materials are easy to work with and yield
a clean fi nal appearance. Joint sealing is easier than other methods because it only requires use of the
standard joint sealant for the type of plastic pipe used. And there are not horizontal seams requiring
sealing like on metal air piping.
Other materials suitable for combustion air venting are galvanized pipe, aluminum pipe and fl exible
aluminum pipe. All joints, including the seams, of these piping materials must be sealed with silicone
adhesive sealant, such as Dow Corning 732.
Terminations
Through-the-roof terminations
Both vent and air piping must terminate with a Heat-fab rain cap.
Sidewall terminations
Vent and air pipes can be individually terminated using Heat-fab termination elbows with built-in screen,
or concentrically terminated using Heat-fab type SC concentric vent/air pipe (only when using Heat-fab
vent piping) termination components as given in this manual.
Heat-fab
EZ Seal
Joint
Assembly
