That's a clever solution. In a different vein, I thought about dismantling the mobile air conditioner and putting it in a cold water bath instead sucking air t

That's a clever solution. In a different vein, I thought about dismantling the mobile air conditioner and putting it in a cold water bath instead sucking air to heat to blow to outside. The lower part is wet anyway from condensate. This summer I did something different and simpler: instead of a hose to outside, I made a wooden frame fitting into the window and strapped the air conditioner to it such that it sucked the air from outside instead from inside. I think it worked better this way because it didn't create negative pressure in the flat anymore and because it could blow the hot waste air directly to the outside. The fans didn't need to fight against the negative pressure and the long hose.