DIYbanter - View Single Post - Adjustiing/mod'ing digital thermostat on LG window air conditioner

wrote:

I also have an LG air conditioner with digital controls and would like
to do the same. Mine is a rather large and expensive unit, so I am
reluctant to butcher it or risk damaging it. I am curious as to what
type of component the temperature sensor is.

If the temperature sensor for the digital controls is a thermistor
then it would be easy to make a circuit involving a central AC
thermostat (you would need a stat that uses a relay output instead of a
triac) and a couple of resistors to emulate the sensor indicating a
high temperature or a low temperature to manually control the
compressor.

If the sensor is some sort of temperature sensitive transistor, it
would be a bit tougher to design a similar circuit. If it's a
thermocouple, it is even worse.

If you were to do something like this you would have to beware of
evaporator coil freeze up, especially at the temperature you wish to
run the unit at, since the temperature sensor is no longer in front of
the coil. Evaporator coil freezup can easily ruin the compressor.

Eric

Eric-Thanks for the reply. I agree about the freeze up potential, have
to keep an eye on it at least initially. I have forced it to run longer
by holding the temp sensor between my fingers for a period of time, so
far minimal frosting on the evaporator. On the other hand, it's not
that humid here at the moment. Another option might be to slightly heat
the sensor with something like a low wattage light bulb placed at a
distance, though again this is kind of a PITA, especially in a bedroom
:-/ This particular unit was fairly cheap, about $160.

Dan