Empire Comfort Systems FG28BMK(N,P)-1 Installation Instructions Manual page 12

It is recommended that the Mantis Power-Vent High-Efficiency
Fireplace be located on an exterior wall for ease of venting. The
flue exhaust pipe and inlet air pipe should be located between wall
studs. The required opening for venting is 1-7/8 inch in diameter
for 1-1/2 inch PVC pipe.
For vent clearances see Figure 1 pg.10.
The bottom of the exhaust vent terminal and the air intake shall be
located at least twelve inches above grade and must be vented
outside. It is recommended the exhaust and intake be located
twelve inches from the maximum snow level.
The flue pipe must be supported on horizontal vent runs. The flue
pipe needs to be supported every three feet. All horizontal runs of
the flue must be pitched ¼ inch per foot towards the the fireplace.
Note: If the vent run dips or sags, condensation may be-
come trapped and cause the unit to not operate properly.
The minimum vent length protruding from outside the wall is six
inches. For two-pipe installation, a minimum distance of three
inches and maximum distance of 24 inches must be maintained
between the pipes. See Figures 2 and 3.
Single flue (one-pipe) installations must have a minimum
clearance of two inches on the back of the heater for combustion
air.
Vent Freezing Protection
When the vent pipe is exposed to temperatures below freezing
(i.e. when it passes through unheated spaces, chimneys, etc.) the
pipe must be insulated with 1/2 inch thick sponge rubber insula-
tion, Armaflex-type insulation or equivalent. Insulating pipe is im-
Figure 2 - Single Flue
Table 1 - Equivalent Vent Length Example
EVL = Equivalent Vent Length
EVL must be greater than or equal to one foot and less than or equal to 40'
EVL = 90º elbow + 4' straight pipe + 45º elbow
EVL = 3' +
(90º elbow)
Page 12
VENTING REQUIREMENTS
4' + 1.5'
(straight pipe) (45º elbow)
portant to avoid condensate icing.
For proper operation, the flue exhaust must be extended six inch-
es from the outside wall before applying an elbow.
SUPPORT
OUTSIDE
WALL
Note: If the vent length requirements are not followed, the
unit will not operate properly.
Figure 3 - Colinear Direct Vent
+ 2' straight pipe + 45º elbow
+ 2' +
(straight pipe) (45º elbow)
6" MIN.
12" MAX.
12" ABOVE
MAXIMUM
EXPECTED
SNOW LEVEL
1/2"
ARMAFLEX
INSULATION OR
EQUIVALENT
(IF REQUIRED)
Figure 4
+ 3' straight pipe = 15'
1.5' + 3'
(straight pipe)
= 15'
31793-3-1015