B) When communicating with the outdoors through
vertical ducts, each opening shall have a minimum
free area of one (1) square inch per 4,000 BTUH
(2.54 cm
2
/1.2 kW) of the total input rating of all gas
appliances in the enclosure (see Figure 5).
C) When communicating with the outdoors through
horizontal ducts, each opening shall have a mini-
mum free area of 1 square inch per 2,000 BTUH
(2.54 mm
2
/0.6 kW) of the total input rating of all
gas appliances in the enclosure (see Figure 6).
When ducts are used, they shall be of the same
cross-sectional area as the free area of the open-
ings to which they connect. The minimum short side
dimension of rectangular air ducts shall not be less
than three (3) inches (7.62 cm).
Louvers and Grills
In calculating free area for ventilation and combustion
air supply openings, consideration must be given to
the blocking effect of louvers, grills, or screens pro-
tecting the openings. Screens must not be smaller
than 1/4 inch (6.4 mm) mesh. If the free area through
a particular design of louver or grill is known, it should
be used in calculating the size of opening required to
provide the free area specified. If the design and free
area is not known, it may be assumed that wood
louvers and grills will allow 20-25% free area and
metal louvers and grills will allow 60-75% free area.
Louvers and grills must be installed in the open posi-
tion or interconnected with the water heater so that
they are opened automatically during water heater
operation.
Corrosive Atmospheres
If this water heater is to be installed in a beauty shop,
barber shop, photo processing lab, dry cleaning
establishment, a building with an indoor pool, or near
a chemical storage area, it is imperative that the
combustion and ventilation air be drawn from outside
these areas. These particular environments contain
products such as aerosol sprays, detergents, bleach-
es, cleaning solvents, refrigerants, and other volatile
compounds that, in addition to being highly flam-
mable, become highly corrosive acid compounds
when burned. Exposure to such compounds can be
hazardous and lead to premature product failure.
Should the water heater fail due to exposure to
such a corrosive atmosphere, the warranty is void.
Venting
When installing the venting system, make sure to fol-
low all local codes or, in the absence of local codes,
CAN/CGA B149 in Canada and/or the National
Fuel Gas Code, ANSI Z223.1 in the United States.
Never operate the water heater unless it is prop-
erly ventilated to the outdoors and has adequate
air supply for proper operation. Failure to properly
install the venting system could result in property
damage, personal injury, or death.
Drafthood installation
The water heater must be vented using the drafthood
provided by the manufacturer. Before installing the
drafthood, check to make sure that the flue baffle
6
INSTALLATION INSTRUCTIONS
Confined Space
Permanent
Opening
--------------
1 square inches /
1000 BTUH
(min. : 100 sq. in)
Outlet air to attic
1 sq. in / 4000 BTUH
Vent
to outdoors
Install above
insulation
Confined Space
Inlet air from the
crawl space
1 sq. in / 4000 BTUH
Open foundation vent
Install above
insulation
Vent
to outdoors
Outlet air to attic
1 sq. in / 4000 BTUH
Confined Space
Inlet air duct
1 sq. in / 4000 BTUH
12'' max.
Inlet
Outlet
Outdoor air duct
1 sq. in. / 2000 BTUH
1 sq. in. / 2000 BTUH
Confined Space
Alternate
air inlet
Entré d'air
Alternative
1 po
2
/ 2000 BTUH
1 po
2
/ 2000 BTUH
Conduit d'air extérieur
Sortie
Entré
12'' max.
Conduit d'entré d'air
1 po
2
/ 4000 BTUH
Évent de fondation
1 po
2
/ 4000 BTUH
Entré d'air du
sous-sol
Espace Restreint
Installez au dessus
de l'isolation
Évent menant
à l'extérieur
Sortie d'air
au grenier
1 po
2
/ 4000 BTUH
Ouverture
Permanente
--------------
1 pouce carré /
1000 BTUH
(min. : 100 po
2
)
Espace Restreint
Évent menant
à l'extérieur
Installez au dessus
de l'isolation
Espace Restreint
Sortie d'air
au grenier
1 po
2
/ 4000 BTUH
Espace Restreint
Figure 6
Confined Space
Permanent
Opening
--------------
1 square inches /
1000 BTUH
(min. : 100 sq. in)
Outlet air to attic
1 sq. in / 4000 BTUH
Vent
to outdoors
Install above
insulation
Confined Space
Inlet air from the
crawl space
1 sq. in / 4000 BTUH
Open foundation vent
Install above
insulation
Vent
to outdoors
Outlet air to attic
1 sq. in / 4000 BTUH
Confined Space
Inlet air duct
1 sq. in / 4000 BTUH
12'' max.
Inlet
Outlet
Outdoor air duct
1 sq. in. / 2000 BTUH
1 sq. in. / 2000 BTUH
Confined Space
Alternate
air inlet
Entré d'air
Alternative
1 po
2
/ 2000 BTUH
1 po
2
/ 2000 BTUH
Conduit d'air extérieur
Sortie
Entré
12'' max.
Conduit d'entré d'air
1 po
2
/ 4000 BTUH
Évent de fondation
1 po
2
/ 4000 BTUH
Entré d'air du
sous-sol
Espace Restreint
Installez au dessus
de l'isolation
Évent menant
à l'extérieur
Sortie d'air
au grenier
1 po
2
/ 4000 BTUH
Ouverture
Permanente
--------------
1 pouce carré /
1000 BTUH
(min. : 100 po
2
)
Espace Restreint
Évent menant
à l'extérieur
Installez au dessus
de l'isolation
Espace Restreint
Sortie d'air
au grenier
1 po
2
/ 4000 BTUH
Espace Restreint
Confined Space
Permanent
Opening
--------------
1 square inches /
1000 BTUH
(min. : 100 sq. in)
Outlet air to attic
1 sq. in / 4000 BTUH
Vent
to outdoors
Install above
insulation
Confined Space
Inlet air from the
crawl space
1 sq. in / 4000 BTUH
Open foundation vent
Install above
insulation
Vent
to outdoors
Outlet air to attic
1 sq. in / 4000 BTUH
Confined Space
Inlet air duct
1 sq. in / 4000 BTUH
12'' max.
Inlet
Outlet
Outdoor air duct
1 sq. in. / 2000 BTUH
1 sq. in. / 2000 BTUH
Confined Space
Alternate
air inlet
Entré d'air
Alternative
1 po
2
/ 2000 BTUH
1 po
2
/ 2000 BTUH
Conduit d'air extérieur
Sortie
Entré
12'' max.
Conduit d'entré d'air
1 po
2
/ 4000 BTUH
Évent de fondation
1 po
2
/ 4000 BTUH
Entré d'air du
sous-sol
Espace Restreint
Installez au dessus
de l'isolation
Évent menant
à l'extérieur
Sortie d'air
au grenier
1 po
2
/ 4000 BTUH
Ouverture
Permanente
--------------
1 pouce carré /
1000 BTUH
(min. : 100 po
2
)
Espace Restreint
Évent menant
à l'extérieur
Installez au dessus
de l'isolation
Espace Restreint
Sortie d'air
au grenier
1 po
2
/ 4000 BTUH
Espace Restreint
Figure 4
Figure 5
WARNING
DANGER
