The furnace should be located as close as possible to chimney or
vent in order to keep vent connections short and direct. The
furnace should also be located as near as possible to center of air
distribution system.
Step 2—Location Relative to Cooling Equipment
When installing furnace with cooling equipment for year-round
operation, the following recommendations must be followed for
series or parallel airflow:
1. In series airflow applications, coil is mounted after furnace in
an enclosure in supply-air stream. The furnace blower is used
for both heating and cooling airflow.
UNIT DAMAGE HAZARD
Failure to follow this caution may reduce the life of this unit.
The coil MUST be installed on air discharge side of furnace.
Under no circumstances should airflow be such that cooled,
conditioned air can pass over furnace heat exchanger. This
will cause condensation in heat exchanger and possible
failure of heat exchanger which could lead to a fire hazard
and/or a hazardous condition which may lead to bodily harm.
Heat exchanger failure due to improper installation may not
be covered by warranty.
2. In parallel airflow applications, dampers must be provided to
direct air over furnace heat exchanger when heat is desired and
over cooling coil when cooling is desired.
IMPORTANT:
The dampers should be adequate to prevent cooled
air from entering furnace. If manually operated, dampers must be
equipped with a means to prevent operation of either cooling unit
or furnace unless damper is in full cool or heat position.
INSTALLATION
Step 1—Air for Combustion and Ventilation
CARBON MONOXIDE POISONING AND UNIT
CORROSION HAZARD
Failure to follow this warning could lead to premature rusting
of heat exchanger and possible premature furnace failure
and/or vent failure which could result in fire hazard and/or
personal injury or death.
Installation of this furnace in an area where it will receive
contaminated combustion air must be avoided. Such contami-
nation would include the following: ammonia, chlorine,
hydrogen sulfide, halogenated hydrocarbons, carbon tetra-
chloride, cleaning solvents, hydrochloric acid, water soften-
ing chemicals, and similar chemicals.
CARBON MONOXIDE POISONING AND FIRE
HAZARD
Failure to follow this warning could result in property
damage, personal injury or death.
Do not block combustion-air openings in the furnace. Any
blockage could result in improper combustion.
Step 2—General
This furnace should be installed in a location in which facilities for
ventilation permit satisfactory combustion of oil, proper venting,
and maintenance of ambient temperature at safe limits under
normal conditions of use. The location should not interfere with
proper circulation of air within the confined space. (See NFPA-31,
Section 1.5.)
In addition to air needed for combustion, process air shall be
provided as required for: cooling of equipment or material,
controlling dew point, heating, drying, oxidation or dilution, safety
exhaust, and odor control.
In addition to air needed for combustion, air shall be supplied for
ventilation, including all air required for comfort and proper
working conditions for personnel.
The barometric draft regulator (included with furnace) shall be
installed in same room or enclosure as furnace in such a manner as
to prevent any difference in pressure between regulator and
combustion-air supply.
Air requirements for operation of exhaust fans, kitchen ventilation
systems, clothes dryers, and fireplaces shall be considered in
determining the adequacy of a space to provide combustion-air
requirements.
The lack of a proper amount of combustion air can lead to serious
furnace operational problems. Some of these problems are:
1. Excessive oil burner after drip and oil fumes.
2. Sooting.
3. Melted igniter/relay control.
4. Air band or air turbulator settings more open than normal.
5. Lockouts on start-up.
The requirements for combustion and ventilation air depend upon
whether the furnace is located in a CONFINED or UNCONFINED
space.
UNCONFINED SPACE
An unconfined space must have at least 50 cu ft for each 1000
Btuh of total input for all the appliances (such as furnaces, clothes
dryers, water heaters, etc.) in the space. (Refer to Table 2.)
In unconfined spaces in buildings of conventional frame, brick, or
stone construction, infiltration MAY be adequate to provide air for
combustion, ventilation, and dilution of flue gases. This determi-
nation must be made on an individual installation basis and must
take into consideration the overall volume of unconfined space, the
number of windows and ventilation openings, the number of doors
to the outside, internal doors which can close off unconfined space,
and overall tightness of building construction. Consideration must
also be given to the amount of storage items (furniture, boxes, etc.)
within the unconfined space which take away from the air volume.
Many new buildings and homes (and older ones that have been
weatherized) MUST BE considered as being of tight construction,
therefore, infiltration will not be sufficient to supply necessary air
for combustion and ventilation.
A building can be considered as being of tight construction when:
1. Walls and ceilings exposed to outside atmosphere have a
continuous water vapor retarder with a rating of 1 perm or less
with openings gasketed or sealed, and/or
Table 2—Minimum Floor Area for Unconfined
Space
58VLR FURNACE
INPUT BTUH
MINIMUM SQ FT WITH
7-1/2 FT CEILING
70,000
467
91,000
607
105,000
700
119,000
793
140,000
933
154,000
1028
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