LAARS Mighty Stack MS-080 (Sizes 199, 300, 399) - Install and Operating Manual User Manual
Page 6

Laars Heating Systems
Page 6
1.6 Locating Appliance for Correct
Horizontal Vent/Ducted Air Distance
From Outside Wall
The forced draft combustion air blower in the
appliance has sufficient power to pull air and vent
properly when the guidelines for horizontal air and
vent are followed (see Table 1).
NOTE: On some models, the vent collar size is
larger than the size of the vent pipe that can be
used. Vent collar size and horizontal pipe diameters
can be found in Table 1. The larger vent collar
size is to accommodate Category I (vertical) vent
systems.
Size
Vent Collar
Size
Horizontal
Vent Pipe
Diameter
Intake
Air Collar
& Pipe
Diameter
Max. Pipe
Length
Max. No.
of Elbows
Side Wall
Vent
Terminal
Part Number
Side Wall
Combustion
Air Terminal
Part Number
in
cm
in
cm
in
cm
ft
m
199
5
13
4
10
4
10
50
15
3
CA003101
CA003201
300
6
15
5
13
4
10
50
15
3
CA003102
CA003201
399
7
18
6
15
6
15
50
15
3
CA003103
CA003202
Table 1. Horizontal Vent / Combustion Air Parameters.
Appliance
Surface
Required
Clearance From
Combustible Material
Recommended
Service Access
Clearance
inches
cm
inches
cm
Left Side
1
2.5
24
61
Right Side
1
2.5
24
61
Top
1
2.5
12
30
Back
1
2.5
**
12**
**
30**
Front
1
2.5
36
91
Vertical
(Category 1)
Vent
*
6*
*
15.2*
Horizontal
(Category 3)
Vent
per UL 1738 venting
system supplier's
instructions
*1" (2.5 cm) when b-vent is used.
**When vent and/or combustion air connects to the back,
recommended clearance is 36" (91cm).
Table 2. Clearances.
NOTE: When located on the same wall, the
Mighty Stack combustion air intake terminal must
be installed a minimum of 12" (30cm) below the
exhaust vent terminal and separated by a minimum
of 36 inches (91cm) horizontally.
The air intake terminal must be installed high
enough to avoid blockage from snow, leaves and other
debris.