Descriptions: Hang the air hose from the air conditioner & dryer out of the window Keeps the warm air outside: This is ideal if you don't want to install the exhaust hose from the tumble dryer or room air conditioner firmly through the wall opening but instead want to hang it through the tilted window. To prevent the air conditioning system from drawing warm air back into the apartment: simply attach the window seal with Velcro. Then open the zipper in the middle a bit, slide the tube out - done. Of course you can also open the zipper completely, e.g. for ventilation. .