Compact Unit Heater
9
Operating Instructions and Owner’s Manual
Vertical Category I Vent System - Vent Pipe Only
FIGURE 6
Vertical Category I Vent System - Vent Pipe and
Air Inlet Pipe, Flat Roof
FIGURE 7
HORIZONTAL VENTING
WARNING: This heater requires a Category III listed vent
system for horizontal venting. Failure to use and properly
install a listed Category III vent system could result in injury
or death from carbon monoxide. Refer to the listed Category
III manufacturer’s instructions for proper installation.
1. Horizontal venting is Category III. Category III vent pipe has a
positive pressure inside the pipe. If Category III vent pipe is not used
and installed per the Category III manufacturers instructions, carbon
monoxide can leak into the building.
2. Category III appliances must be vented in vent pipe listed to UL
1738. Use any listed vent system manufacturer.
3. Do not attach the vent pipe or inlet pipe to any other appliances
or vent systems. This heater must have a dedicated vent pipe and
inlet pipe.
4. Do not mix different brands and types of Category III vent pipe.
5. Refer to Table 6 for total minimum and maximum vent lengths.
6.
The equivalent length of a 90° elbow is 5’ (1.5 m) for 4” (10.2
cm) diameter and 7’ (2.1 m) for 6” (15.2 cm) diameter.
7. Refer to Figures 8 and 9 for horizontal venting requirements.
8. Horizontal sections of vent pipe are to be installed with a
minimum downward slope from the appliance of 1/4 inch per
foot (6.35 mm per 30.5 cm). If local code allows, a 1/4 inch per
foot upward slope can be installed.
9. Securely support horizontal vent and inlet air pipe every 3 feet
(0.91 m) with steel strapping or other material that can withstand
the temperature and rigidity required.
10.
Maintain 6” clearances between the vent pipe and combustible
surfaces or materials. Greater distances may be necessary if
surfaces or materials can be damaged by high heat.
11. A tee with drip leg, cap and condensate drain should be installed
at the lowest point of the vent pipe prior to exiting the structure/
building.
12. The vent pipe and inlet pipe (separated combustion models) must
terminate with a listed vent terminal/cap with the size listed in
Table 4.
13.
The vent pipe must extend 20” (50.8 cm) beyond the exterior
surface of an exterior wall or further if there is a potential for
heat damage on building materials.
14.
The air inlet pipe must extend 4” (30.5 cm) beyond the exterior
surface of the exterior wall.
15. Do not terminate the vent pipe over public walkways or over
an area where condensate or vapor could create a nuisance or
hazard or could be detrimental to the operation of regulators,
relief openings, or other equipment.
16. The vent pipe and inlet pipe (separated combustion models) must
be installed 12” (30.5 cm) above the snow line. Consider snow
drifts.
17.
The inlet air pipe must be a minimum of 12” (30.5 cm) apart from
the vent pipe, and 4” (10.2 cm) from the exterior wall.
TABLE 6
Vent Pipe Diameters and Total Equivalent Pipe
Lengths for Horizontal Venting
Model Size
Vent Pipe
Diameter
Equivalent Vent Length
Minimum
Maximum
100-150
4” (10.2 cm)
5’ (1.5 m)
30’ (9 m)
200
4” (10.2 cm)
5’ (1.5 m)
50’ (15.25 m)
250-400
6” (15.2 cm)
5’ (1.5 m)
50’ (15.25 m)
