Laars NTH1000, Installation And Operation Instructions Manual, Page: 16 / 140

LAARS Heating Systems Page 12
It is the responsibility of the appropriately licensed
technician installing this NeoTherm LC to use
ULC S636 certified vent material consistent with
the requirements as described in the Venting and
Combustion Air section.
Class I venting systems are suitable for gas-fired
appliances producing flue gas temperature of more
than 135°C, but not more than 245°C.
Class II venting systems are suitable for gas-fired
appliances producing flue gas temperatures of 135°C
or less.
Class II venting systems are further classified into
four temperature ratings as follows:
A
Up to and including 65°C
B Up to and including 90°C
C Up to and including 110°C, and
D Up to and including 135°C
Flue Gas Sampling Port -
It is also the responsibility of the installer to ensure
that a flue gas sampling port is installed in the
vent system. This flue gas sampling port must be
installed near the flue connection of the NeoTherm
LC: within 2 feet of the flue connection. There is
no flue gas sampling port internal to the NeoTherm
LC, so one must be installed in the vent system
external to the NeoTherm LC. A flue gas sampling
port available as a component of the ULC S636
certified vent system is preferred. However, if one
is not available with the certified vent system, Laars
suggests using a tee with the branch connection
sized to allow for insertion of a flue gas analyzer
probe. The branch connection must be resealable
with a cap or other means to ensure the vent system
remains sealed. (See Fig. 8.)
Consideration must be given to the placement
and orientation of the flue gas sampling port to
ensure that condensate is free to flow back into the
NeoTherm LC and not collect anywhere in the vent
system - including in the flue gas sampling port.
Exhaust Vent Terminal -
An exhaust vent terminal must be installed. If an
exhaust vent terminal is not available with the
certified vent system, Laars suggests the use of a
coupler fitting from the certified vent system into
which the vent terminal screen can be installed.
Be sure to install and terminate both vent and
combustion air pipes per the instructions in this
section.
3.3 Locating the Vent and Combustion
Air Terminals
3.3.1 Side Wall Vent Terminal
The appropriate Laars side wall vent terminal must
be used. The terminal must be located in accordance
with ANSI Z223.1/NFPA 54 and applicable
local codes. In Canada, the installation must be
in accordance with CSA B149.1 or .2 and local
applicable codes.
Consider the following when installing the terminal:
1. Figure 9 shows the requirements for
mechanical vent terminal clearances for the
U.S. and Canada.
2. Vent terminals for condensing appliances or
appliances with condensing vents are not
permitted to terminate above a public walkway,
or over an area where condensate or vapor
could create a nuisance or hazard.
3. Locate the vent terminal so that vent gases
cannot be drawn into air conditioning system
inlets.
4. Locate the vent terminal so that vent gases
cannot enter the building through doors,
windows, gravity inlets or other openings.
Whenever possible, avoid locations under
windows or near doors.
Fig. 8 - Test Port