[zeroflow]

As someone who also did the dual-hose conversion.

For some background, you probably know that the AC works by sucking in air and then outputting one stream that's hotter and one stream that's colder. The cold air is blown into the room and the hot air is ventilated out the hose. The problem now is, that the hot air you blow out of the room creates a vacuum and in turn sucks in hot air from the outside. So you constantly take some of the nice cool air of your room and heat it up and blow it out of the building. The dual hose setup instead takes air from outside for the heating up part.

The dual-hose setup should go in tandem with a well isolated window insert. For my mod, I simply taped a cardboard box to the inlet side of the AC unit and created a second opening into the polycarbonate plate covering the window opening.

> Did you manage to get an improvement of efficiency?

Yes, definately. I didn't do any scientific measurement, but after the mod, my workspace did get a lot cooler than before.

> What model of A/C were you using ? De Longhi Pinguino PAC N81