Install Instructions

8 • Residen al Standard Gas Water Heater Use and Care Guide
GETTING STARTED
8 • Residen al Standard Gas Water Heater Use and Care Guide
GETTING STARTED
Example:
Gas Burning Appliance BTU/HR Ra ng
Gas Water Heater 40,000
Furnace 75,000
Dryer 20,000
Total 135,000
Your Appliances:
Gas Burning Appliance BTU/HR Ra ng
Gas Water Heater
Total
Table 2 provides examples of minimum
square footage (area) required for
various BTU/HR totals. Areas used for
storage or which contain large objects
containing less air than is assumed for
the room sizes in Table 2 – see Op on
A for more specifi c calcula ons.
Op on A: Installa on without
outside ven la on (not recom-
mended)
Ven la on with outside air is recom-
mended for all installa ons. Even if
the water heater is installed in a large,
open room inside the house, outdoor
air is usually needed because modern
homes are very  ghtly sealed and
o en do not supply enough air to the
water heater. However, when installed
in a large indoor space, it may be pos-
sible to provide enough air without
outside ven la on. If you are unsure if
your installa on loca on has enough
ven la on, contact your local gas
u lity company or code offi cials for a
safety inspec on.
The following instruc ons will help de-
termine if it may be possible to install
without outside ven la on. Even if
this may be possible, you will need to
conduct the vent dra test on pages
23-24 when installa on is fi nished. If
there is not enough ven la on, you
will need to ven late with outside air.
Check for Chemicals:
Installa ons where corrosive chemi-
cals may be present require outside
air. Air for combus on and ven la on
must be clean and free of corrosive or
acid-forming chemicals such as sulfur,
fl uorine, and chlorine. Ven la on with
outside air will reduce these chemicals,
but it may not completely eliminate
them. Failure due to corrosive chemi-
cals is not covered by the warranty.
Examples of loca ons that require
outside air due to chemicals include:
• Beauty salons
• Photo processing labs
• Indoor pools
• Laundry, hobby, or cra rooms
• Chemical storage areas
Products such as aerosol sprays, de-
tergents, bleaches, cleaning solvents,
gasoline, air fresheners, paint and
varnish removers, and refrigerants
should not be stored or used near the
water heater.
A1: Calculate the air volume of
the room
Air requirements depend on the size of
the room.
Floor Area (Square feet) X Ceiling
Height (feet) = Room Volume (cubic
feet)
If there are large objects in the room
(e.g., refrigerator, furnace, car), sub-
tract their volume from the volume of
the room to get a be er es mate of
the air available.
Room Volume – Object Volume = Air
Volume
Table 2
BTU/HR Minimum Square Typical Room
Input Feet with 8’ Ceiling with 8’ Ceiling
30,000 188 9 x 21
45,000 281 14 x 20
60,000 375 15 x 25
75,000 469 15 x 31
90,000 563 20 x 28
105,000 657 20 x 33
120,000 750 25 x 30
135,000 844 28 x 30