[roeme]

I do more or less agree with you, but:

> what's the point of building something badly that you can buy COTS from any hardware store for only slightly more than what she spend on this thing?

Tinkering. Hacking. Learning.

> turn AC on and off through cutting off power) will wreak havoc on her AC

I don't know alot about AC's (I generally eschew them), but there is one line in the article:

Make sure that your AC is always set to be ‘on’, we’re bypassing the air conditioner’s normal on/off control system.

I can't image they've got a complicated startup sequence if they've got an "always-on" setting? Or am I wrong?

[joezydeco]

I think he means an air conditioner with a physical on/off switch. If the unit has an electronic control that needs an "on" press to turn it on after power is applied, this external relay won't work.