Page 12 BRADFORD WHITE CORP.
2.3.3 Vertical Vent Terminal
When the unit is vented through the roof, the
vent must extend at least 3 feet (0.9m) above the point
at which it penetrates the roof. It must extend at least
2 feet (0.6m) higher than any portion of a building
within a horizontal distance of 10 feet (3.0m), and high
enough above the roof line to prevent blockage from
snow. When the combustion air is taken from the roof,
the combustion air must terminate at least 12" (30cm)
below the vent terminal (see Figure 2).
2.3.4 Vertical Combustion Air Terminal
When combustion air is taken from the roof, a
eld-supplied rain cap or an elbow arrangement must
be used to prevent entry of rain water (see Figure 2).
The opening on the end of the terminal must be at least
12" (30cm) above the point at which it penetrates the
roof, and high enough above the roof line to prevent
blockage from snow. When the vent terminates on the
roof, the combustion air must terminate at least 12"
(30cm) below the vent terminal.
2.4 Common Vent Test — BoilersWhen an existing boiler is removed from a
common venting system, the common venting system
is likely to be too large for proper venting of the
appliances remaining connected to it.
At the time of removal of an existing boiler, the
following steps shall be followed with each appliance
remaining connected 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 deciencies which could cause an unsafe
condition.
3. Insofar as it is practical, close all building doors
and windows and all doors between the space in
which the appliances remaining connected to the
common venting 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 exhausts, so they
will operate at maximum speed. Do not operate a
summer exhaust fan. Close replace dampers.
4. Place in operation the appliance being
inspected. Follow the lighting instructions.
Adjust thermostat so appliance will operate
continuously.
5. Test for spillage at the draft hood relief opening
after 5 minutes of main burner operation. Use
the ame of a match or candle, or smoke from a
cigarette, cigar or pipe.
6. 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,
replace dampers and any other gas burning
appliance to their previous conditions of use.
7. Any improper operation of the common venting
system should be corrected so that the installation
conforms to the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 and/or CSA B149.1, Installation
Codes. 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 Part
II of the National Fuel Gas Code, ANSI Z223.1/
NFPA 54 and/or CSA B149.1, Installation Codes.
2.5 Vent Terminals for Outdoor UnitsFor outdoor applications, the vent and
combustion air openings must be covered with proper
terminals to prevent rain, snow and other objects from
falling into the Copper Brute II.
If local codes allow, outdoor installations may
use 1' of appropriately sized galvanized single wall
or B-Vent and a rain cap for exhaust vent termination
in the default conguration (venting out of the top).
An appropriately sized galvanized 90° ell, positioned
with the opening facing down, may be used on the
combustion air inlet in the default conguration on
the back of the unit. Note that some local codes may
require a higher vertical vent height, extending above
any perimeter fencing, etc. In installations where the
appearance of the vent is objectionable, the low prole
vent terminals in Table 6 may be used.
Part numbers for the low prole terminals to
cover the vent and combustion air openings are shown
in Table 6.
OUTDOOR OUTDOOR
SIZE VENT COMBUSTION
TERMINAL AIR TERMINAL
500 20254703 D2007900
750 20254705 D2007900
1000 20254705 D2008000
1250 D2007700 D2008000
1500 D2007700 D2008000
1750 D2007800 D2008000
2000 D2007800 D2008200
Table 6. Vent Terminals for Outdoor Units.