INSTALLATION AND OPERATION INSTRUCTIONS
1-14
SFC BOILER / WATER HEATERS - SFC 199
Vent terminal clearance minimums are as follows:
VENT TERMINAL MINIMUM CLEARANCES
CANADIAN
INSTALLATIONS
1
US INSTALLATIONS
2
A= Clearance above grade,
veranda, porch, deck, or
balcony
12 in (30 cm)
12 in (30 cm)
B= Clearance to window or
door that may be opened
6 in (15 cm) for appliances
≤ 10,000 Btuh (3 kW), 12
in (30 cm) for appliances >
10,000 Btuh (3 kW) and ≤
100,000 Btuh (30 kW), 36
in (91 cm) for appliances
>100,000 Btuh (30 kW)
6 in (15 cm) for appliances
≤ 10,000 Btuh (3 kW), 9 in
(23 cm) for appliances >
10,000 Btuh (3 kW) and ≤
50,000 Btuh (15 kW), 12
in (30 cm) for appliances >
50,000 Btuh (15 kW)
C= Clearance to
permanently closed window
*
*
D= Vertical clearance to
ventilated soffit located
above the terminal within a
horizontal distance of 2 ft
(61 cm) from the center line
of the terminal.
*
*
E= Clearance to
unventilated soffit
*
*
F= Clearance to outside
corner
*
*
G= Clearance to inside
corner
*
*
H= Clearance to each side
of center line extended
above meter/regulator
assembly
3 ft (91 cm) within a height
15 ft above the meter/
regulator assembly
*
I= Clearance to service
regulator vent outlet
Above a regulator within
3 ft (91 cm) horizontally of
the vertical center line of
the regulator vent outlet
to a maxiumum vertrical
distance of 15 ft (4.5 m)
*
J= Clearance to
nonmechanical air supply
inlet to building or the
combustion air inlet to any
other appliance
6 in (15 cm) for appliances
≤ 10,000 Btuh (3 kW), 12
in (30 cm) for appliances >
10,000 Btuh (3 kW) and ≤
100,000 Btuh (30 kW), 36
in (91 cm) for appliances
>100,000 Btuh (30 kW)
6 in (15 cm) for appliances
≤ 10,000 Btuh (3 kW), 9 in
(23 cm) for appliances >
10,000 Btuh (3 kW) and ≤
50,000 Btuh (15 kW), 12
in (30 cm) for appliances >
50,000 Btuh (15 kW)
K= Clearance to a
mechanical air supply inlet
6 feet (1.83 m)
3 ft (91 cm) above if within
10 ft (3 m) horizontally
L= Clearance above paved
sidewalk or paved driveway
located on public property
7 ft (2.13 m) †
*
M= Clearance under
veranda, porch deck, or
balcony
12 in (30 cm) ‡
*
1 In accordance with the current CSA B149.1 Natural Gas and Propane Installation Code
2 In accordance with the current ANSI Z223.1 / NFPA 54 National Fuel Gas Code
† A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family
dwellings and serves both dwellings.
‡ Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
* Clearance in accordance with local installation codes and the requirements of the gas supplier.
WARNINGS
- In addition to preventing
ingestion of chemical
contaminants, care must
be taken to ensure air
intake terminals are not
installed in locations where
contamination might occur
due to ingestion of particulate
foreign material (dust, dirt
and debris).
- Intake air openings must
be configured such that rain
or other forms of moisture
cannot enter the air intake
piping system. Otherwise
serious damage to the unit
may result.
