You guys have made a few good points.
Yes, this guy has a thousand dollar control and many sensors attached to the unit, but he also has a program written to calculate instantaneous SEER and integrate it with his home automation. Point being although he does not do it cheap, it could be done very cheap. In my mind all that is really needed beyond standard heatpump parts are the pressure transducer, and a timer(to terminate defrost). If you want to get fancy, a thermistor on the output of the evap would give you more of a demand termination solution. This is how I plan to run mine.
Mejunkhound, the LED and photosensor is something another member, Xringer I believe, has done some experimenting with, though I'm not sure what his results were.
Adam
|