4-522.4
4
installation
combustion air requirements
For complete combustion, 14-1/2 lbs. of air is required for
each pound of No. 2 fuel oil. Lack of combustion air can cause
erratic burner operation, noisy combustion, fuel odors and soot
deposits on heat exchanger walls resulting in lowered efficiency
and high fuel consumption.
Units installed in tightly sealed buildings or confined spaces
must be provided with two permanent openings, one near
the top of the confined space and one near the bottom. Each
opening should have a free area of not less than one square
inch per 1,000 BTU per hour of the total input rating of all units
in the enclosure with a minimum of 100 square inches for each
opening, whichever is greater, freely communicating with interior
areas having, in turn adequate infiltration from the outside.
For further details on supplying combustion air to a confined
(tightly sealed) space or unconfined space, see the National
Fuel Gas Code ANSI Z223.1 of CAN/CGA B149.1 or .2
Installation Code, latest edition.
confined of unconfined spaces
The National Fuel Gas Code defines an “unconfined space” as
a space whose volume is greater than 50 cubic feet per 1000
Btu/Hr input of the installed appliance(s). A confined space
is 50 cubic feet or less per 1000 Btu/Hr input of the installed
appliance(s).
unit suspension
1.
Be sure the means of suspension is adequate to support
the weight of the unit (see Table 17.1 for unit weights).
2.
For proper operation, the unit must be installed in a level
horizontal position.
3.
Clearances to combustibles as previously specified must be
strictly maintained.
4.
It is recommended that adequate service access in access
of 18 inches be provided for the burner and fan limit switch.
5.
Do not install unit heater above the maximum mounting
height shown in Table 17.2.
Four tapped holes (1/2" - 13) in the top of the unit are provided
for unit heater suspension. Suspension can be made with
threaded rods, pipes, or ceiling hanger brackets furnished by
others. See Figure 17.1 for hanger hole locations and Figure 4.1
for suspension methods.
note: A pipe hanger adapter kit, shown in figure 4.1 is
available as an accessory from Modine, or can be self-
fabricated. Kit consists of two drilled 3/4" I.P.S. pipe caps and
two 1/2" - 13 x 1-3/4" capscrews to facilitate threaded-pipe
suspension. Two kits are required for mounting each unit.
figure 4.1 - suspension methods
venting
1. To dispose of flue gasses, all oil-fired heaters must be
vented per NFPA No. 31 “Installation of Oil Burning
Equipment” and all local codes.
2. Do not install chimney connector closer than 18 inches
to combustible materials in any direction. Where chimney
connector passes through a wall or partition, a metal
ventilated thimble not less than 12 inches larger in diameter
than the connector must be used.
3. All Modine oil-fired heaters have an 8 inch vent connection.
Never use a chimney connector smaller than 8 inches,
except a 7 inch adapter may be used on Model POR100 to
accomodate a 7 inch vent.
4. Install a barometric draft control the same size and on
the vent pipe as close to the unit as possible. Installing a
barometric draft control is essential for proper operation
of the unit. Excessive over fire draft can cause unburned
fuel to accumulate in the stack creating a potentially
explosive condition. To install barometric draft control, refer
to instructions furnished by draft control manufacturer. The
air flow opening of the barometric draft control should face
the front of the unit heater or away from air currents in the
vicinity of the heater.
THE BAROMETRIC DRAFT CONTROL MUST BE ADJUSTED
TO PROVIDE MINUS 0.02 INCHES W.C. (WATER COLUMN)
OVERFIRE DRAFT AS MEASURED BETWEEN THE DRAFT
CONTROL AND THE UNIT AND AS CLOSE TO THE UNIT AS
POSSIBLE.
CAUTION
1. Do not install units below 7 feet, measured from the
bottom of the unit to the floor, unless properly guarded to
provide protection from moving parts.
2. Do not install unit heater or vent pipe closer than 18
inches to combustible materials in any direction, except
the front of the unit heater, which must be unobstructed.
WARNING
Oil-fired heating equipment must be vented - do not operate
unvented.
CAUTION
A barometric draft control must be installed on each unit
heater, in the same space as the unit heater and as close to
the unit as possible.
