39
Majestic • MER36MN, MER42MN Installation Manual • 2599-980 Rev. B • 5/23
5
5
Vent Clearances and Framing
Figure 5.1 Horizontal Venting Clearances To Combustible
Materials
WARNING! Risk of Fire!
Elbow heat shield required
when V
1
= 2 ft. or less. Clearances to combustibles must
be maintained. See Figure 4.11.
A. Vent Clearances to Combustibles
WARNING! Risk of Fire!
Maintain air space clearance
to vent.
DO NOT
pack insulation or other combustibles:
• Between ceiling firestops
• Between wall shield firestops
• Around vent system
Failure to keep insulation or other material away from
vent pipe could cause overheating and fire.
SCREW
3 in.
(76 mm)
To Install Elbow Heat Shield:
1. Remove the elbow heat shield from the shipping posi
-
tion by removing screws.
2. Fasten the shield in place using the four pilot holes.
The shield should be oriented such that the dimension
(longest dimension) is running in the same direction
the elbow is pointing. The shield should be centered
directly above the elbow, and positioned so that it cre
-
ates a 1/2 inch airspace between the shield and the
combustible surface. See Figure 5.2.
Top vented appliances: Installation of the elbow heat
shield is required when the clearance to combustible ma
-
terial above the first 90 degree vent elbow is three inches
or less. See Figure 5.1.
Note:
A minimum of three inches clearance from the top
of the pipe to any combustible material must always be
maintained.
WARNING! Risk of Fire!
Elbow heat shield
MUST
be
installed if required. Overheating will occur.
Elbow Heat Shield
CORRECT
INCORRECT
COMBUSTIBLE SURFACE
DIRECTION
UP
HEAT SHIELD
90º ELBOW
Figure 5.2 Elbow Heat Shield Installation
* When using SLP pipe, minimum clearances from the vent pipe to combustible
materials at inside wall firestops are:
Top: 2-1/2 in. (64 mm)
Bottom: 1/2 in. (13 mm)
Sides: 1 in. (25 mm)
Note: Heat shields MUST overlap by a minimum of 1-1/2 in. (38 mm).
•
DVP heat shield
- designed to be used on a wall 4 in. to 7-1/4 in. (102 mm to 184
mm)
thick
.
• If wall thickness is less than 4 in. the existing heat shields must be field trimmed. If
wall thickness is greater than 7-1/4 in. a DVP-HSM-B will be required.
•
SLP heat shield
- designed to be used on a wall 4-3/8 in. to 7-5/8 in. (111 mm to
194 mm thick).
• If wall thickness is less than 4-3/8 the existing heat shields must be field trimmed.
If wall thickness is greater than 7-5/8 in. a DVP-HSM-B will be required.
(DVP-SLP Pipe Shown)
3 in. (76 mm)
top clearance *
1 in. (25 mm)
clearance
bottom & sides
Heat
Shield
Wall
Shield
Firestop
Heat
Shield
WALL
3 in. (76 mm)
top clearance min.
1 in. (25 mm)
clearance around
vertical sections
Elbow
Heat
Shield
Warning! Risk of Fire: Elbow heat shield required with 3 inch top
clearance or V1 of 2 ft. or less.
V1
