Continental Electronics 816R - Exhaust Duct and Air Filter

transmitter exhaust air into the room and all
outside outlets and inlets will be closed.
The system described will require two heating type
thermostats and control relays. One will be set to
approximately 65° F and the second will be set to
approximately 85° F.
At temperatures above 85° F, the first condition
described above will exist.
For temperatures between 65° F and 85° F the
second condition described above will exist.
For temperatures below 65° F the third condition
described above will exist.
The thermostats should be mounted approximately
seven feet off the floor and in an area of the room
where the temperature is not influenced by heat
radiated by the transmitter or by direct air flow
from the room intake fan.
The transmitter space should also be provided with
a thermostatically controlled heater that can be set
to approximately 50° F. This will provide heat
during maintenance periods or during times that the
transmitter is off-the-air, if not a 24 hour operation.
Transmitter Exhaust Duct
Regardless which air system is used, careful
consideration must be given to location of
transmitter, air intake, and air outlet vent when
using outside air for cooling room and equipment.
First, consider where to place the transmitter. The
transmitter exhaust will be vented to the outside
and transmitter will take air from the room. Since
the transmitter will exhaust to the outside, the
exhaust vent on the transmitter should be placed as
close as possible to an outside wall. Although it is
highly undesirable, it is possible to exhaust through
the roof but extreme care must be used to
weatherproof and leak proof the ductwork above
the transmitter. Since water that may leak at the
ductwork will likely get into the transmitter, it is
absolutely necessary to check for leak proofing
often. In any case the ducts must be kept as short as
possible to minimize back pressure at the
transmitter outlet. Remember that elbows, vent
caps, and hoods all add extra resistance to air flow
through the transmitter. In most installations, the
transmitter can be placed so that no more than eight
feet of exhaust duct is needed. If this is possible, 16
inch round duct or the equivalent rectangular duct
will be acceptable. Do not use more than two
elbows. It is not a good practice to connect more
than one transmitter to the same exhaust duct. Let
each transmitter have its own individual exhaust
duct.
Where possible use large ductwork instead of duct
fans. Duct fans may be required if the duct run is
long but duct fans increase air resistance if they
fail; therefore, some method of monitoring and
interlocking to the transmitter must be used if there
is no alternative to the use of duct fans.
External Air Filter
The original air filter for the 816R series
transmitters is adequate for most installations.
There are situations where the air may be
extremely dirty. Because the air intake opening is
only 16 inches square, you must not place
additional filters or furnace type filters on the
transmitter ’ s air intake opening in an attempt to
correct this situation. An external filter assembly
may be necessary if the transmitter room is not
clean or if the air entering the room is difficult to
filter properly.
The external filter holder assembly shown on the
reverse side of this page is designed to accept two
20" X 20" X 2" Extended Surface Pleated filters.
This filter assembly can be attached directly to the
top of the transmitter over the air intake replacing
the original filter. Just one 20" X 20" X 2" filter
of this type has about nine square feet of filter
surface. Grainger, a supplier found in most larger
cities, carries the “ Air Handler ” brand. FARR is
another popular manufacturer of this type filter.
In addition to the greater surface area of the filter
material, two 20" X 20" openings reduce the air
velocity through each filter and allows them to be
much more effective than with the original 16"
square filter opening.
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