LAARS NeoTherm NTV (Sizes 150–850 MBTU/h) - Install and Operating Manual - Manual (Page 16)

Page 12 LAARS Heating Systems
NeoTherm and shown in the Unpacking section, be installed.
Be sure to install and terminate both vent and combustion
air pipes per the Venting and Combustion Air section of the
NeoTherm instructions.
3.3 Locating Vent and Combustion Air
Terminals
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 points listed on the
following page when installing the terminal.
1.
Figure 12 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.
5. Locate the vent terminal so that it cannot be blocked
by snow. The installer may determine that a vent
terminal must be higher than the minimum shown in
codes, depending upon local conditions.
6. Locate the terminal so the vent exhaust does not settle
on building surfaces or other nearby objects. Vent
products may damage surfaces or objects.
7. If the boiler or water heater uses ducted combustion air
from an intake terminal located on the same wall, see
Figures 12-14 for proper spacing and orientation.
If the vent termination is located in an area exposed to high
winds, an optional PVC tee (the same diameter as the vent
pipe) may be used. The tee’d vent termination offers greater
protection from wind related operating issues.
Side Wall Combustion Air Terminal
The LAARS side wall combustion air terminal, or concentric
terminal must be used when the heater takes air from a side
wall. (See Table 3.) Contact Laars for AL29-4C termination
fittings. Consider the following when installing the terminal.
(See Figures 12-14.)
1.
Do not locate the air inlet terminal near a source of
corrosive chemical fumes (e.g., cleaning fluid, chlorine
compounds, etc.)
2. Locate the terminal so that it will not be subject to
damage by accident or vandalism. It must be at least 7
feet (2.1m) above a public walkway.
3. Locate the combustion air terminal so that it cannot be
blocked by snow. The National Fuel Gas Code requires
that it be at least 12 inches (30cm) above grade, but the
installer may determine it should be higher, depending
upon local conditions.
4. If the NeoTherm is side-wall vented to the same wall,
locate the vent terminal at least 1 foot (0.3m) above the
combustion air terminal.
5. For concentric vent, follow instructions included
with vent kit.
6. Multiple vent kits should be installed such that the
horizontal distance between the outlet group and the
inlet group is 36” (90cm). (See Figure 13.)
7. The vent outlet for models 80-285 must be no lower
than the center of the air inlet, and must be at least 12”
(30cm) away from the air inlet. Vent outlets for models
399-850 must be at least 12” above the top of the air
inlet, and must be at least 36” (90cm) horizontally from
the air inlet. (See Figure 14.)
Vertical Vent Terminal
When the unit is vented through the roof, the vent must extend
at least 3 feet (0.9m) above the point at which it penetrates
the roof. It must extend at least 2 feet (0.6m) higher than
any portion of a building within a horizontal distance of 10
feet (3.0m), and high enough above the roof line to prevent
blockage from snow. The vent terminal included with the
NeoTherm can be used in both vertical and horizontal
applications. When the combustion air is taken from the roof,
the combustion air must terminate at least 12” (30cm) below
the vent terminal. (See Figure 10.)
Vertical Combustion Air Terminal
When combustion air is taken from the roof, a field-supplied
rain cap or an elbow arrangement must be used to prevent
entry of rain water. (See Figure 10.) The opening on the end
of the terminal must be at least 12” (30cm) above the point at
which it penetrates the roof, and high enough above the roof
line to prevent blockage from snow. When the vent terminates
on the roof, the combustion air must terminate at least 12”
(30cm) below the vent terminal.
Installations in the Commonwealth of
Massachusetts
In Massachusetts the following items are required if the
side-wall exhaust vent termination is less than seven (7) feet
above finished grade in the area of the venting, including but
not limited to decks and porches. From Massachusetts Rules
and regulations 248 CMR 5.08 (begininning on 2nd page
following):