Review on 🌬️ HOOMEE 400CM (157") Universal Window Seal for Portable Air Conditioner and Tumble Dryer – Compatible with All Mobile Air-Conditioning Units, Quick Installation - Air Exchange Guards with Zipper and Adhesive Fastener by Jay Hill

I've been struggling for a number of years to effectively seal my double French door to ventilate my portable air conditioner. The best I could do was cut and replace a giant piece of cardboard from the packaging box to cover the entire window frame. Blocked the light, wasn't airtight and very very ugly. This is a simple, low-tech solution. Dual access zippers (for 2-hose A/C systems) allow the hand to adjust and reposition the (single) vent hose "tip" if needed while holding the hose tight. While not exactly an aesthetic ideal, the strip of white fabric is much more discreet than cardboard, as only one side of the window is open, just enough to accommodate the width of the tubing. The curtains stay in place, I have daylight and the street view is barely noticeable. And, yes (!), the air conditioning cools effectively. Having to align the top of one open side of the window, as well as the vertical gap between them, he took up almost the entire length of the fabric, leaving only a few inches. I'm in a dry area so there has only been one wind/rain in a few months but it has held up. Once the weather got cooler and the A/C was on, I also had to remove the velcro strip to be able to close the window normally. It's lost most of its "stickiness" so you might need to buy/cut something new next time.