Raypak MVB 5042004 - Manual (Page 29)

29
** Subtract 10 ft per elbow. Max. 4 elbows.
t Adapters supplied by others.
Table N: Category III Horizontal Vent & Horizontal Direct Vent
See Table L for Category I venting guidelines.
It is recommended that the intake vent be insulated in
colder climates.
Termination
The flue terminal should be vertical and should termi-
nate outside the building at least 2 ft above the highest
point of the roof within 10 ft. The vent cap should have
Fig. 28: Direct Vent - Vertical
a minimum clearance of 4 ft horizontally from and in no
case above or below (unless a 4 ft horizontal distance
is maintained) electric meters, gas meters, regulators
and relief equipment. The distance of the vent terminal
from adjacent public walkways, adjacent buildings,
open windows and building openings must be consis-
tent with the NFGC (U.S.) or B149 (Canada).
Flues supported only by flashing and extended above
the roof more than 5 ft should be securely guyed or
braced to withstand snow and wind loads.
The air inlet opening MUST be installed 1 ft above the
roof line or above normal snow levels that might ob-
struct combustion air flow. This dimension is critical to
the correct operation of the heater and venting system
and reduces the chance of blockage from snow. The
vent cap must have a minimum 3 ft vertical clearance
from the air inlet opening.
Outdoor Installation
Outdoor models must be vented with listed vent mate-
rial per the following instructions and installed with the
optional factory-supplied outdoor vent kit. A special
vent cap and air intake hood are provided in accor-
dance with CSA requirements. These must be
installed as illustrated in Fig. 29.
Care must be taken when locating the heater out-
doors, because the flue gases discharged from the
Model
No.
Certified
Vent
Material
Vent
Size
(in.)
Maximum
Horizontal
Vent Length
(ft)**
Combustion Air
Intake Pipe
Material
Air Inlet
Max. Length** (ft)
6” Ш 8” Ш 10” Ш
504
Category III
8
75
Galvanized Steel,
PVC,
ABS,
CPVC
45 100 t 754 10
1104 10
1504 12
45 85 t
2004 14
CAUTION: This venting system requires the
installation of a condensate drain in the vent piping
per the vent manufacturer’s instructions. Failure to
install a condensate drain in the venting system will
void all warranties on this heater.
WARNING: No substitutions of flue pipe or vent
cap material are allowed. Such substitutions would
jeopardize the safety and health of inhabitants.