put a coating of waterproof sealant
over the air flow assembly’s foil, exposed
wires, connections, and leads.
After you determine the method
you are going to use to control the
A/C, mount the Smart A/C Controller
in a convenient location.
With the MODE switch in the
NORMAL position, the display shows
the temperature of the room.
When power is first applied, the
green Compressor On LED will flash
twice. Then, the red Low Airflow LED
will flash once, as will the Freeze Up
LED. This sequence indicates that
both MCUs are operating properly.
Next, the display will show the
temperature in degrees Fahrenheit.
(If you want to display Celsius, install
optional DIPSW1 and put position 1
ON.) The default compressor delay is
five minutes. If a jumper is placed at
J6, the delay is three minutes.
You can find the temperature of
the thermostat setting by momentarily
pressing either the UP or DOWN
buttons. The setting will flash for 10
seconds. While the display is flashing,
you can set the temperature using
the UP and DOWN buttons.
With the MODE switch is in the
TIPS ON SETTING UP
A WALK-IN COOLER
As mentioned earlier, the Smart
A/C Controller’s original purpose was
for use in a walk-in cooler that used an
inexpensive room air conditioner as a
cooling source. If you plan on using
this project for this purpose, I have a
few tips for you. If you use an average
sized air conditioner, the room should
be less than 1/2 the size of the rating
of the air conditioner and it must be
well insulated. The best way to do this
is to use foam insulating sheeting to
partition off a room. This partitioning
job is, in fact, quite easily done. The
primary problem is the door. I used a
combination sliding insulating door
and clear plastic vertical strips. Another
tip: Don’t set the thermostat below
38°F. You want to start out at 45°F.
superb laser detection
high resistance to
temperature changes and
Hint: A small fan blowing on the
A/C’s evaporator coil may help reduce
ice build-up and thus could make the
A/C more efficient.
October 2008 47