P-K MACH
®
Gas Fired Boiler
Technical Service 1.877.728.5351
Revised: January 3, 2020
Released: January 3, 2020
Patterson-Kelley 2020
All Rights Reserved.
1004905981 P-K MACH C1500H-C4000 Installation and
Owners Manual (Rev F Jan-2020).docx
Page 27
United States Minimum Area of Ventilation Openings per Boiler (Sq. In)
P-K MACH
®
Boiler
MODEL
AIR SOURCE
INDOOR AIR SUPPLY
OUTDOOR AIR SUPPLY
SAME
FLOOR
DIFF
FLOORS
ONE
OPENING
TWO OPENINGS
DIRECT
VERT
DUCT
HORIZ
DUCT
C-1500H
1500
3000
500
375
375
750
C-2000H
2000
4000
667
500
500
1000
C-2500
2500
5000
833
625
625
1250
C-3000
3000
6000
1000
750
750
1500
C-4000
4000
8000
1334
1000
1000
2000
3.4.2 Air Inlet Requirements - Canada
Air inlet requirements for the Canadian Provinces are established by CAN/CSA B149.1.
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.
(6,500 mm
2
), whichever is greater.
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 1/4 inch.
3. Motorized louvers shall be interlocked with the appliance so that they are
proven open prior to main burner ignition and operation.
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. (6,500 mm2), whichever is greater.
B.
Use the following opening calculation for
P-K MACH
®
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 mm2/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. When combustion air is supplied by natural airflow into a space containing the type of appliance
described in
Paragraph B
, the cross sectional area of the opening shall not be 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
.
D. When a duct is used to meet the requirement for combustion air supply, as described in
Paragraphs A
through C
, 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.
E. When combustion air is supplied by mechanical means, an airflow-sensing device must be installed. It
must be wired into the pre-ignition limit/interlock to prevent the burner from starting or to stop an operating
burner in case of air supply failure.
F. 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 E
do not apply.
NOTES:
