Installation, Operation and Maintenance Instructions User guide
LAARS Heating Systems
Page 8
commencing within 12” (300 mm) of the top and
one commencing within 12” (300 mm) of the
bottom, of the enclosure shall be provided. The
openings shall communicate directly, or by ducts,
with the outdoors or spaces that freely communicate
with the outdoors. When directly communicating
with the outdoors, or when communicating to the
outdoors through vertical ducts, each opening shall
have a minimum free area of 1 square inch per
4000 Btu/hr (550 square mm/kW) of total input
rating of all equipment in the enclosure. When
communicating to the outdoors through horizontal
ducts, each opening shall have a minimum free
area of not less than 1 square inch per 2000 Btu/
hr (1100 square mm/kW) of total input rating of all
equipment in the enclosure.
Method 2: One permanent opening, commencing
within 12” (300 mm) of the top of the enclosure,
shall be permitted. The opening shall directly
communicate with the outdoors or shall
communicate through a vertical or horizontal duct
to the outdoors or spaces that directly communicate
Section 3
VENTING AND COMBUSTION AIR
3.1 Combustion Air
MagnaTherm boilers and water heaters must have
provisions for combustion and ventilation air in
accordance with the applicable requirements for
Combustion Air Supply and Ventilation in the
National Fuel Gas Code, ANSI Z223 1; or in Canada,
the Natural Gas and Propane Installation Code, CSA
B149.1. All applicable provisions of local building
codes must also be adhered to.
A MagnaTherms can take combustion air
from the space in which it is installed, or the
combustion air can be ducted directly to the unit.
Ventilation air must be provided in either case.
3.1.1 Combustion Air From Room
In the United States, the most common requirements
specify that the space shall communicate with the
outdoors in accordance with Method 1 or 2. (See the
following descriptions.) Where ducts are used, they
shall be of the same cross-sectional area as the free
area of the openings to which they connect.
Method 1: Two permanent openings, one
Table 3. Ducted Air Accessories
(Place in section 3.1)
Model 2000 Model 2500 Model 3000 Model 3500 Model 4000
Screen for horizontal galvanized air pipe D2012101 D2012101 D2012102 D2012103 D2012103
Screen for horizontal PVC air pipe CA012001 CA012001 CA012002 CA012003 CA012003
Screen for horizontal polypropylene air pipe CA012201 CA012201 CA012202 CA012203 CA012203
Screen for vertical galvanized air pipe D2012201 D2012201 D2012202 D2012203 D2012203
Screen for vertical PVC air pipe CA012401 CA012401 CA012402 CA012403 CA012403
Screen for vertical polypropylene air pipe CA012601 CA012601 CA012602 CA012603 CA012603
Table 3a - Ducted Air Accessories
(Place in section 3.2)
Model 2000 Model 2500 Model 3000 Model 3500 Model 4000
Horizontal vent terminal for stainless steel D2012001 D2012001 D2012002 D2012003 D2012003
Screen for horizontal CPVC vent CA012101 CA012101 CA012102 CA012103 CA012103
Screen for vertical stainless steel vent D2012301 D2012301 D2012302 D2012303 D2012303
Screen for vertical CPVC vent CA012501 CA012501 CA012502 CA012503 CA012503
Table 3* - Vent Accessories
(Place in section 3.5)
Model 2000 Model 2500 Model 3000 Model 3500 Model 4000
Air intake screen for unit placed outdoors CA011901 CA011901 CA011902 CA0011903 CA0011903
Vent terminal for unit placed outdoors CA011801 CA011801 CA011802 CA011803 CA011803
Table 3** - Air & Vent Accessories for Units Placed Outdoors
Table 4. Required Combustion Air Pipe Material
Material United States Canada
ABS ANSI/ASTM D1527 The air pipe material must be chosen based upon
the intended application of the boiler, and must
be installed according to the vent manufacturer’s
installation instructions.
PVC, sch. 40 ANSI/ASTM D1785 or D2665
CPVC, sch. 40 ANSI/ASTM F441
Single wall galv. steel 26 gauge
Polypropylene ULC S636 Class 2C