Installation Guide

10 • Residen al Standard Gas Water Heater Use and Care Guide
GETTING STARTED
10 • Residen al Standard Gas Water Heater Use and Care Guide
GETTING STARTED
covering (in decimals – e.g., 60% = .6)
For example, an installa on area that
requires openings with 100 square
inches of free area would need 134
square inch openings if using metal
louvers rated at 75% free area (100 sq.
in. ÷ .75 = 134 sq. in.).
If you do not know the % free area for
your louver or grill, use the following
values:
• For wood louvers or grilles: 20%
• For metal louvers or grilles: 60%
Follow these rules to ensure that vents
and ducts provide adequate air fl ow:
• Each vent opening must be no
smaller than 100 square inches .
• Ducts must have the same cross-
sec onal area as free area of the
opening.
• Rectangular ducts must have a
minimum dimension of no less
than three inches .
• All screens must have mesh ¼” or
larger.
• Moveable louvers must be locked
open or interconnected with the
equipment so that they open au-
toma cally during opera on.
• Keep louvers and grills clean and
free of debris or other obstruc-
 ons.
B5: Check that air source is
clean and free of chemicals
Air for combus on and ven la on
must be clean and free of corrosive
or fl ammable chemicals. A failure due
to corrosive chemicals in the air is not
covered by the warranty. Combus-
 on air must be free of acid-forming
chemicals such as sulfur, fl uorine, and
chlorine. Be sure that air at the vent
inlets is free of such chemicals.
B6: Check that combus on
ven la on is adequate
To confi rm that your installa on has
enough combus on air, conduct the
vent dra test on pages 23-24 when
installa on is fi nished.
Combus on Air Supply Op ons
Figure 3 - Direct to outdoors openings
Figure 4 - Vertical duct openings
Figure 5 - Horizontal duct openings
Figure 6 - Single opening