14
Harsco Industrial, Patterson-Kelley Technical Service 1.877.728.5351
INST
alla
TION
Gas Fired Boiler
15
Harsco Industrial, Patterson-Kelley Technical Service 1.877.728.5351
INST
alla
TION
Gas Fired Boiler
under no circumstances shall
the boiler room ever be under
a negative pressure.
Particular
care should be taken when
exhaust fans, compressors, air-
handling units or other equipment
may rob air from the boiler. Note
that this equipment might be
in rooms other than the boiler
room. This applies to both sealed
combustion and atmospheric
room combustion air applications.
!
WARNING
3.5.2.1 Air Inlet Requirements — united states (
NFPA 54/ANsI Z223.1 & NFPA/ANsI 211
)
When air is supplied from inside the building, the total required volume
shall be the sum of the required volume for all the appliances located
in the mechanical room. Adjacent rooms furnished with fixed openings
communicating directly with the mechanical room are considered part of the
required volume. The minimum volume is 50 ft
3
per 1000 Btu/hr (4.8 m
3
/kW) of
installed appliance input capacity.
Openings used to connect indoor spaces to obtain the required minimum
volume shall be sized as follows:
•
When rooms are on the same floor, each opening shall have an area equal to
1 square inch for each 1000 Btu/hr (2200 mm
2
/kW) of installed appliance input
capacity, but not less than 100 square inches. One opening should commence
less than 12 inches above the floor and the other less than 12 inches below the
ceiling. The minimum dimension of air openings shall be 3 inches.
•
When rooms are on different floors, each opening shall have an area equal to 2
square inches for each 1000 Btu/hr (4400 mm
2
/kW) of installed appliance input
capacity.
When combustion air is supplied from outside the building, the boiler room
shall be provided with one or two openings to ensure adequate combustion air
and proper ventilation.
When using one permanent opening, the opening shall commence within
12 inches of the ceiling and shall communicate directly with the outdoors or
through a vertical or horizontal duct that communicates to the outdoors.
Minimum free area of the opening is 1 square inch for each 3000 Btu/hr (700
mm
2
/kW) of installed appliance input capacity, and not less than the sum of
the areas of all vent connectors in the room.
When using two permanent openings, one opening shall commence within
12 inches above the floor and the other within 12 inches below the ceiling, preferably on opposite walls. The openings
shall communicate directly, or by way of ducts, with free outdoor air. The minimum net free area of the openings shall be
calculated in accordance with the following:
•
When air is taken directly from outside the building, each opening (minimum of two, as outlined above), 1 square inch for
each 4,000 Btu per hour (550 mm
2
/kW) of total boiler input is required.
•
When air is taken from the outdoors through a vertical duct into the mechanical room, 1 square inch per 4,000 Btu per hour
(550 mm
2
/kW) of total boiler input is required.
•
When air is taken from the outdoors through a horizontal duct into the mechanical room, 1 square inch per 2,000 Btu per
hour (1100 mm
2
/kW) of total boiler input is required.
n
oTe
:
1. The required size of openings for
combustion and ventilation air shall
be based on the net free area of the
opening.
2. Screens shall be not smaller than ¼”
3. Motorized louvers shall be
interlocked with the appliance so that
they are proven open prior to main
burner ignition and operation.
3.5.2.2 Air Inlet Requirements – Canada (CAN/CsA B149.1)
A. Ventilation of the space occupied by fuel burning appliance(s) or equipment shall be supplied by a ventilation
opening at the highest practicable point communicating with the outdoors. The total cross sectional area of the
ventilation opening must be either 10% of the net free area required for combustion air or 10 sq. in. (6500 mm
2
),
whichever is greater.
n
oTe
:
1. The free area of a combustion
air supply opening is calculated by
deducting the blockage area of any
fixed louvers, grilles or screens from
the total area of the opening.
2. Screens shall be not smaller than ¼”
3. Motorized louvers shall be
interlocked with the appliance so that
they are proven open prior to main
burner ignition and operation.
P-K sONIC™
Boiler model
AIR sOuRCe
INDOOR AIR suPPly
OutDOOR AIR suPPly
sAme FlOOR DIFF FlOORs ONe OPeNING
tWO OPeNINGs
DIReCt
VeRt DuCt
hORIZ DuCt
SC-3000
3000
6000
1000
750
750
1500
SC-4000
4000
8000
1334
1000
1000
2000
US Minimum area of ventilation openings per boiler (sq inches)
B. Use the following opening calculation for P-K SONIC™, MACH® or
MODU-FIRE® FD
boilers:
When combustion air is supplied for a forced draft burner by natural airflow from
the outdoors and there is no draft regulator or draft hood in the same space, there
shall be a permanent opening with a cross sectional area not less than 1 sq. in/
30,000 Btu/Hr (70 mm
2
/kW) of the total rated input to the burner(s). This opening
must not interfere with the ventilation air opening defined in paragraph A.
C. Use the following opening calculation for
P-K THERMIFIC®
boilers or
other natural draft or fan-assist appliances:
When combustion air is supplied for natural or fan-assisted burners by natural
airflow from the outdoors, there shall be a permanent opening with a cross
sectional area not less than 1 sq. in/7000 Btu/Hr (321 mm
2
/kW) up to and
including 1,000,000 Btu/Hr plus 1 sq. in./14,000 Btu/Hr (155 mm
2
/kW) in excess
1,000,000 Btu/Hr. This opening must be either located at or ducted to a point not more than 18 in. (450 mm) or less than 6 in.
(150 mm) above floor level. This opening is in addition to the ventilation air opening defined in paragraph A.
D. When combustion air is supplied by natural airflow into a space containing both types of appliance described
in paragraphs B and C, the cross sectional area of the opening shall be not less than the sum of the cross
sectional areas for all appliances in the space as calculated by the applicable method. This opening is in addition
to the ventilation air opening defined in paragraph A.
E. When a duct is used to meet the requirement for combustion air supply, as described in paragraphs A through
D, above, the opening of the duct shall be located so there is no possibility of cold air affecting steam or water
piping, electrical equipment or mechanical equipment.
F. When combustion air is supplied by mechanical means, an airflow-sensing device must be installed. It must be
wired into the pre-ignition limit string to prevent the burner from starting or to stop an operating burner in case of
air supply failure.
G. When all combustion air is supplied through a make-up air heater, and the appliance is interlocked to the
heater, the requirements of paragraphs A through F do not apply.
P-K sONIC™ Boiler
Required Combustion Air Opening
Ventilation Air Opening
model
Input (Btu/hr)
in
2
mm
2
in
2
mm
2
SC-3000
3,000,000
100
64,516
10
6,452
SC-4000
4,000,000
134
86,451
13.4
8,645
3.5.3 Flue Venting
This boiler is not certified for use with Type "B" vent nor with
PVC
venting.
P-K SONIC™
boilers are dual certified as a Category II and Category IV appliances, as defined in
ANSI Z21.13/CSA
4.9
, latest edition. The vent material must be as listed in the Table of Acceptable Materials for Venting Systems in
Section 3.5.1.2 above. The exhaust vent can be run horizontally or vertically.
Vent installations shall be in accordance with
NFPA54/ANSI Z223.1
, the National Fuel Gas Code, or
CAN/
CSA-B149.1
, the Natural Gas and Propane Installation Code, or applicable provisions of the local building codes.
Canadian minimum Area of Combustion and Ventilation Air Openings
3.5.3.1 Vent sizing
The vent must be sized in accordance with the
ASHRAE
Systems and Equipment handbook, Chapter 30 or
according to the vent manufacturer’s recommendations. When using manufactured venting systems, consult your
vent supplier for correct sizing and structural support requirements.
P-K sONIC™ Boiler model
Frictional Resistance
stack temperature
CO2 Natural Gas
CO2 lP Gas
SC-3000/SC-4000
0.22” wc
220 °F
9.2%
10.4%
Vent Design Parameters
Table 3.5.2.1
Table 3.5.2.2
Table 3.5.3.1
