Sealed Combustion/Direct Vent Systems; Inlet Duct Connection To Boiler; Intake Duct Materials And Sizes; Removing An Existing Boiler - Harsco Industrial P-K SONIC SC-3000 Installation & Owner's Manual

designed to prevent backflow of exhaust gas through idle boilers. For combined breeching installations, please
follow recommendations of a qualified venting engineer/manufacturer.
It is recommended that if using common venting the common vent should be designed for maximum
continuous pressure of -.04" wc with sizing equal throughout the run, and tee's be used on the outlet of
the boilers with locking dampers on the exhaust directly off the boilers and combustion air dampers on
the combustion air inlets.

3.5.5 sealed Combustion/Direct Vent systems

These boilers are also certified for operation with a sealed combustion air and
pressurized venting system. Such a system employs a sealed combustion
air intake duct leading from outdoors and a sealed exhaust vent terminating
outdoors. Air flow through the system is maintained by the combustion air fan.
Allowable configurations of vent and air intake terminations are illustrated to
the right. Note, drains have been omitted for clarity.
The combined pressure drop of the air supply duct and exhaust vent must
not exceed 0.44" wc This pressure drop includes both the inlet and exhaust
duct friction loss. Note - the inlet air duct loss should not exceed 0.22" wc.
Both the air inlet if used and the exhaust vent must terminate on the same wall
of the building and must utilize the same type of termination fitting. Allowable
termination fittings are: 90° elbows or tees.
This boiler may be installed with sidewall vent using room air. (Refer to air
inlet requirements Section 3.5.2.1)
Figure 3.5.5 shows the sidewall penetration requirements. The exhaust vent must be at least 3 feet above the air
intake. The air intake and exhaust vent must extend 6" to 12" from the exterior wall and be offset.

3.5.5.1 Inlet Duct Connection to Boiler

Connect the air supply duct to the inlet air collar on the boiler. The air inlet collar is 11.875"
inlet duct to the collar with sheet metal screws at 90° angles and seal with aluminum tape or sealant.

3.5.5.2 Intake Duct materials and sizes

The air intake duct can be fabricated from
PVC
galvanized steel, or other suitable materials. The duct must be rigid enough
to maintain the full required cross sectional area under all operating
conditions. Proper sealing of the intake ductwork is necessary to prevent
infiltration of air from conditioned space. Joints in
cemented. For galvanized duct, wrap each joint and seam with adhesive aluminum tape or other sealant. The
installation of a birdscreen on the intake termination is recommended. Ensure that the screen does not become
blocked with snow, ice, insects etc.

3.5.6 Removing an Existing Boiler

When 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, while the other appliances remaining connected to the common
venting system are not in operation, the following steps should be followed with each appliance remaining
connected to the common venting system placed 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 that there is no blockage or
restriction, leakage, corrosion or other deficiency which could cause an unsafe condition.
3. Insofar as is practical, close all building doors and windows and all doors between the space in which the appliances
Harsco Industrial, Patterson-Kelley Technical Service 1.877.728.5351
18
Figure 3.5.5
OD
. Fasten the air
Air Requirements – sCFm
, , single wall
CPVC
Boiler mODel
SC-3000
SC-4000
must be
PVC CPVC
or
Gas Fired Boiler
remaining connected to the common venting system are located and other
spaces of the building. Turn on clothes dryers and any appliances 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 fireplace dampers.
4. Place the appliance being inspected in operation. Follow the lighting
instructions. Adjust the thermostat so that the appliance will operate continuously.
5. 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.
36" 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, fireplace dampers and any other gas-burning
appliance to their previous conditions of use.
12"
Minimum
Any improper operation of the common venting system should be
corrected so the installation conforms to the National Fuel Gas Code,
and
CSA B149
ANSI Z223.1
the common venting system, the common vent system should be resized
to approach the minimum size as determined using the appropriate tables
in part 11 of the National Fuel Gas Code,
Natural Gas and Propane Installation Code.
CAN/CSA B149.1
3.6 g p
as IpIng
Before making the gas hook-up, make sure the boiler is being supplied
with the type of fuel shown on the boiler nameplate.
The boiler shall be installed such that the gas ignition system components
are protected from water (dripping, spraying, rain, etc.) during appliance
operation and service (circulator replacement, control replacement, etc.)
The boiler is factory fire-tested and adjusted for proper combustion. The
gas train components are certified to handle a maximum inlet pressure of
14" wc (1/2 psig). Typical gas pressure supply for natural gas is 7" wc (11"
wc for propane). If the available gas pressure exceeds 14" wc, a suitable
additional intermediate gas pressure regulator of the "lock up" type must
Required sCFm
be provided to reduce the pressure to less than 14" wc. Refer to boiler
629
label for minimum inlet gas pressure.
839
Install a sediment trap (drip leg) and a union connection ahead of the primary manual shutoff valve on the boiler.
Table 3.5.5.2
A gas piping schematic is shown below. Gas piping should be installed in accordance with National Fuel Gas
Code,
ANSI Z223.1
latest edition. In the Commonwealth of Massachusetts, the gas cock must be a "T-handle type."
Pipe Capacity for Natural Gas
Nominal Internal
Iron Diameter
Pipe (Inches)
size
(Inches)
2.469
2.5
3.068
3
4.026
4
Installation Code. When resizing any portion of
and/or
NFPA 54
ANSI Z223.1 /
, latest edition, and any other local codes which may apply; in Canada see
Table 3.6
Equivalent Pipe
maximum Capacity in Cubic Feet of Natural Gas Per hour
Pressure Drop of 0.5 inch Water Column/Equivalent Length of
length
Pipe (in feet)
o
90 ell tee 20 40 60
(Feet) (Feet)
6.16 4350 3000 2400
12.3
7.67 7700 5300 4300
15.3
10.1 20.2 15800 10900 8800
Harsco Industrial, Patterson-Kelley Technical Service 1.877.728.5351
Gas Fired Boiler
!
WARNING
All threaded connections must
be made using a pipe compound
that is resistant to the action of
liquefied petroleum gases. Do
not use Teflon tape on gas line
threads.
n !
oTICe
See Pipe Capacity for Natural
Gas chart on the following page
for required pipe size, based
on overall length of pipe from
meter plus equivalent length of
all fittings. Approximate sizing
may be based on 1 cubic foot
of natural gas per 1,000 Btu per
hour input, i.e., 3,000,000 Btu per
hour requires about 3,000 cubic
feet per hour. (See "Typical Boiler
Operating Conditions," Section 4.4
for more information.)
r g
eCoMMended as
p I
IpIng nsTallaTIon
Gas
Remote Gas
Supply
Shuto
Drip Leg
Boiler Main Gas
Meter Valve
Union
Figure 3.6
,
CAN/CSA-B.149.1
80 100 150 200
- - - -
3700
- - -
7500 6700 5500 4600
19