Rheem 97MDV060 Series Installation Instructions Manual page 29

GENERAL VENTING REQUIREMENTS AND
NON-DIRECT VENT (VERTICAL TERMINATIONS ONLY)
ALL FURNACE INSTALLATIONS MUST COMPLY WITH
THE NATIONAL FUEL GAS CODE, NFPA 54, AND IN
CANADA CSA B149.1; CANADIAN NATURAL GAS AND
PROPANE INSTALLATION CODE, THE NATIONAL FIRE
CODE OF CANADA, AND LOCAL CODES TO PROVIDE
ADEQUATE COMBUSTION AND VENTILATION AIR FOR
THE FURNACE. FAILURE TO DO SO CAN RESULT IN
EXPLOSION, FIRE, PROPERTY DAMAGE, CARBON
MONOXIDE POISONING, PERSONAL INJURY OR DEATH.
For improved indoor air quality, added safety and product per-
formance we recommend direct vent type installations. If non-di-
rect type vent system is used, the requirements for combustion
air must be provided as identified in the National Fuel Gas Code
and, in Canada, CSA B149.1; Canadian Natural Gas and
Propane Installation Code.
Combustion air requirements are determined by whether the fur-
nace is in an open (unconfined) area or in a confined space
such as a closet or small room.
READ AND FOLLOW THE GENERAL VENTING REQUIRE-
MENTS AND GUIDELINES OF THIS MANUAL FOR ADDI-
TIONAL VENTING REQUIREMENTS PERTAINING TO ALL
FURNACE INSTALLATIONS (INCLUDING DIRECT AND
NON-DIRECT VENTING). FAILURE TO FOLLOW ALL IN-
STRUCTIONS IN THIS MANUAL CAN RESULT IN EQUIP-
MENT FAILURE, EQUIPMENT DAMAGE, PROPERTY
DAMAGE, PERSONAL INJURY OR DEATH.
CONFINED AND UNCONFINED SPACES
The below instructions are for U.S. installations only. The terms
Confined Space and Unconfined Space refer to U.S. installa-
tions only. In Canada the proper term to use is Enclosure when
specifying that a furnace is installed in a partially enclosed or
fully enclosed room or space. For Canadian installations, to de-
termine combustion air requirements for non-direct vent installa-
tions, the installer must follow CSA B149.1; Canadian Natural
Gas and Propane Installation Code and NOT the below instruc-
tions.
T BLE 6: MINIMUM SP CE REQUIREMENTS
FOR UNCONFINED SP CE, NON-DIRECT VENT
GUIDELINES
FURNACE LOCATED IN AN UNCON-
FINED SPACE (U.S. INSTALLATIONS)
USING INDOOR AIR FOR COMBUSTION:
1,000 BTUH of total input for all appliances in the space. Table
An unconfined space must have at least 50 cubic feet for each
6 below specifies minimum space requirements and a few ex-
amples of the room sizes required for different inputs. The sizes
are based on 8-foot ceilings.
If the open space containing the furnace is in a building with
tight construction, outside air may still be required for the fur-
nace to operate and vent properly. Outside air openings should
FURNACE LOCATED IN A CONFINED
be sized the same as for a confined space.
SPACE (U.S. INSTALLATIONS)
input rating which is smaller than that which is specified in Table
A confined space is defined as any space for a given furnace
6 as minimum for an "unconfined" space. If the space is less than
that specified in this table, the space is defined as "confined".
If the space is small enough to be designated as "confined", it
must have openings into the space which are located in accor-
dance with the requirements set forth in the following subsec-
outside, and by the input of ALL appliances in the space.
tions A and B. Size connected to the heated area or to the
If the confined space is within a building with tight construction,
combustion air must be taken from outdoors or from an area
A. USING INDOOR AIR FOR COMBUSTION:
freely communicating with the outdoors.
IMPORTANT: Air should not be taken from a heated space
with a fireplace, exhaust fan or other device that may pro-
duce negative pressure.
If combustion air is taken from the heated area, the open-
ings must each have at least 100 square inches of free
area. Each opening must have at least one square inch of
Table 7 shows some typical examples of openings required
free area for each 1,000 BTUH of total input in the space.
for combustion air openings required for a confined space.
T BLE 7: MINIMUM FREE RE
OPENING REQUIRED FOR
FURN CE LOC TED IN
CONFINED SP CE USING
INDOOR IR FOR COMBUSTION.
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