39
Common Venting
The NFGC does not address sizing guidelines for the
common venting of multiple Category IV heaters. This is
covered in the NFGC under “Engineered Vent Systems”.
Table T
and
provide heater discharge vent pressures at
vent pressure switch and volumes of flue products at full
fire for the calculation of appropriate vent and extractor
sizing for common venting.
Raypak does not support common venting under positive-
pressure conditions. Use an external variable-speed
extractor to draw the stack to negative pressure. See
Figure 41
. Interlock the extractor to each connected heater
at terminals #17 and #18 (See
Figure 26
) to ensure that
no connected heaters will fire until the extractor is proven
operational.
F10569
EXRACTOR’S
PRESSURE
SET POINT
SLOPE TOWARD APPLIANCE
1" IN 4' MINIMUM
(25.4 mm IN 1.2 m)
VENT DRAIN W/ TRAP
ROUTE TO CONDENSATE
TREATMENT OR
CONDENSATE PUMP
ADJUSTABLE
CAT IV VENT
DAMPER/BAFFLE
(TYP)
VENT PIPE SAME
DIAMETER AS BOILER
VENT (CAT IV)
COMMON VENT PIPE
(CAT II)
VARIABLE SPEED
EXTRACTOR
2X D
MAX
D
TEST PORT
BOOT TEE
ALT. LOCATION
VARIABLE SPEED
EXTRACTOR
VENT DRAIN W/ TRAP
ROUTE TO CONDENSATE
TREATMENT OR
CONDENSATE PUMP
◦
Figure 41. Typical Common Venting
Condensate Treatment
The condensate must be drained properly to protect the
appliance and drainage system. The condensate from
the heater condensate drain is acidic. Its pH is typically
between 3.2 and 4.5.
The factory installed Condensate Treatment Kit is
connected to the condensate drain of the heater contains
treatment media to raise the pH level of the condensate.
The pH of the effluent entering a sanitary drain must be
5.0 or higher.
A
A
CAUTION:
In general, the condensate piping from
the appliance must have a downward slope of 1/4" per
horizontal foot. Condensate drain traps must be primed
with water to prevent gas flue leaks. Treatment kits
should be checked at least once per year. To ensure the
pH of the effluent is 5.0 or higher, the media should be
replenished as necessary. When replacing the media,
they should be no smaller than 3/4" to avoid blockage in
the condensate piping.
A
A
WARNING:
Do not install the heater outdoors if
freezing conditions are typical. The condensate will
freeze and back up the flue system.
A
A
CAUTION:
Condensate drain lines must not be
allowed to freeze. Take appropriate measures.
Vent pipe condensate drains are also required for
installation of the XFiire when using PVC or CPVC. Follow
instructions for location of condensate drains in the vent.
A
A
CAUTION:
In general, the condensate piping from
the appliance must have a downward slope of 1/4"
per horizontal foot. Condensate drain traps must be
primed with water to prevent flue gas leaks. Condensate
Treatment Kits should be checked at least once per year.
To ensure the pH of the effluent is 5.0 or higher, the
treatment kit must be replaced as necessary. Contact a
Raypak representative.
Summary of Contents for Xfiire 1000B
Page 54: ...54 6 WIRING DIAGRAM For a full size drawing visit www raypak com ...
Page 70: ...70 NOTES ...
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