General Venting Guidelines; Existing Common Vent Systems; Vent System Options - RBI Futera XLF Series Manual

intake air option – Horizontal guidelines
The maximum equivalent length for the horizontal intake air pipe is
100 ft, 30.5 m. Each 90 elbow and the intake air terminal are equal
o
to 10 linear ft, 3.0 m of pipe. If horizontal runs exceed 5 ft, 1.5 m
they must be supported at 3 ft, 0.9 m intervals with overhead hangers.
The certified intake air terminal from RBI must be used, see Figure 1,
page 8, Figure 2, page 8 and Figure 4, page 9.

GenerAL VentinG GUiDeLines

The vent installation must be in accordance with
Part 7, Venting of Equipment, of the National
Fuel Gas Code, ANSI Z223.1/NFPA 54–
latest revision or applicable provisions of the local
building codes. Canadian installations must comply
with CAN/CGA B149.1 or .2 Installation Code.
Improper venting can result in excessive levels of
carbon monoxide which can result in severe personal
injury or death!
All vent systems must be fully supported by the building structure
and not by the boiler/water heater. Appropriate thimbles and fire-
stops must be used where required.
Common vent systems must be properly engineered
and sized to provide a negative draft of 0.03 inch,
0.8 mm to 0.1 inch, 2.5 mm W.C. at the flue outlet.
Common positive pressure vent systems are not to be
used. Improper installation can result in excessive levels
of carbon monoxide which can cause severe personal
injury or death!
Common-vent systems —
the vertical vent must be assigned as the master
boiler and always fired First to ensure proper
draft and reliable operation
if any questions. Improper installation can result in
excessive levels of carbon monoxide which can cause
severe personal injury or death!

eXistinG common Vent systems

If an existing boiler/water heater is removed from an existing com-
mon venting system, the common venting system may then be too
large for the proper venting of the remaining appliances connected
to it. At the time of removal of an existing boiler/water heater, the
following steps shall be followed with each appliance remaining con-
nected to the common venting system placed in operation, while
the other appliances remaining connected to the common venting
system are not in operation.
1. Seal any unused openings in the common venting system.
2. Visually inspect the venting system for proper size and horizontal
pitch and determine there is no blockage or restriction, leakage,
corrosion and other deficiencies which could cause an unsafe
condition.
3. Insofar as is practical, close all building doors and win-
dows and all doors between the space in which the ap-
pliances remaining connected to the common venting
6
Finned copper tube gas boilers & water heaters – Boiler manual
4.
5.
6.
7.

Vent system options

The flue products in the vent system may be cooled below their dew
the boiler closest to
point and form condensate in the flue. The materials used for a Cat-
egory IV vent must be resistant to any corrosive damage from flue
gas condensate. The flue from a Category IV vent system must have
. Consult the factory
a condensate drain with provisions to properly collect and dispose
of any condensate that may occur in the venting system.
the Futera XLF may be vented the following ways:
1.
2.
system are located and other spaces of the building. Turn
on clothes dryers and any appliance not connected to the
common venting system. Turn on any exhaust fans, such
as range hoods and bathroom exhaust, so they will operate at
maximum speed. Do not operate a summer exhaust fan for a
boiler installation. Close fireplace dampers.
Place in operation the appliance being inspected. Follow the
lighting instructions. Adjust thermostat so appliance will oper-
ate continuously.
Test for spillage at the draft hood relief opening after 5 minutes
of main burner operation. Use the flame of a match or candle, or
smoke from a cigarette, cigar or pipe.
After it has been determined that each appliance remaining
connected to the common venting system properly vents when
tested as outlined above, return doors, windows, exhaust fans,
fireplace dampers and any other gas-burning appliance to their
previous condition of use.
Any improper operation of the common venting system should
be corrected so the installation conforms with the National Fuel
Gas Code, ANSI Z223.1/NFPA 54. When resizing any portion
of the common venting system, the common venting system
should be resized to approach the minimum size as determined
using the appropriate Tables in Appendix F in the National Fuel
Gas Code, ANSI Z223.1/ NFPA 54 and or CAN/CGA B149
Installation Codes.
Category IV vent/air piping lengths must not exceed
100 equivalent feet. If longer runs are required, use a
Category II (negative pressure) vent system, specially
engineered/designed to meet all applicable codes.
option 1 — Direct Vent, positive pressure
category iV (individual venting only) (page 7)
Combustion air is piped from the outdoors to the blower inlet.
Vent system is certified to UL 1738 for installations in the
United States, ULC S636 for installations in Canada. Maxi-
mum equivalent length of vent and air piping must not exceed
100 feet each.
option 2 — Vertical Vent, positive pressure
category iV (individual venting only) (page 10)
Combustion air is obtained from the space in which the unit is
installed. Vent system is certified to UL 1738 for installations in
the United States, ULC S636 for installations in Canada. Maxi-
mum equivalent length of vent piping must not exceed 100 feet.
FTXLF-IOM-HN-1-110308 Copyright 2008 Mestek, Inc.