Portable A/c - how to seal sash window

[BigmouseLittlehouse]

Hi everyone

For medical reasons my mum has invested in a portable A/C. She has sash windows and just wondering if anyone has advice on how to seal round the window kit? Is it worth buying one of those slider kits or can you just do it with a bit of fabric? It won’t be used unless very hot, so really looking for something that can be put up and down easily.

Any nifty ideas grateful received!

Would a foam block cut to size work? Something like this www.dunelm.com/product/foam-bench-seat-pad-1000069806

Thanks sniffy yes that might be worth a try as could cut to size. Thanks