[protomyth]

I've got temp sensors in the mix, but I can have the same temp near the duct for a bit after the blowing stops. I also want to make sure the blower stays at the same rate and isn't sputtering.

[joezydeco]

How about monitoring the compressor itself and not it's output? Maybe a hall-effect sensor attached to the outside of the unit could work?

[protomyth]

I cannot make alterations to the environment or put stuff outside, nice thought though.

// ND -40F in winter - not allowed to cut holes in wall and no extra power outside.