hole
The hole I am talking about is 25cm x 25cm
Unfortunately I found out that this is a glass window(painted) so I cant just cut it.
My idea for quick fix is to try and cut the fan metals with grinder. Then I could stick some wood there. The problem is that from outside in second photo It doesnt seem easy to reach. because the roof is 5mm glass and shattered. I honestly don't know how they put AC unit there.
Any ideas how to fill this hole ?
I realize that this is a U.S. reference, but you may be able to find a wall exhaust fan locally similar to this.
You need to find a unit that is intended for exposure to the outdoors. Also you may need a cover in the colder months if the unit you find does not have a self closing louver. The one depicted does.
If you use 110 voltage and 60cycles, you may be able to order something like this from the U.S. Otherwise, be sure that it matches your local electric supply.
Get a can of expandable foam from your hardware store. If they have it get the one for extra large gaps. Also pick up a tub of ready mixed tile grout. If the hole is really deep the foam may fall through before it had time to expand so you may need to stuff some newspapers into the hole to give the foam some thing to rest on until it had time to set up. Get as thick a layer of foam in there as possible for insulation.
After it has set, trim it off half an inch below floor level and trowel in the grout mixture level with the floor.
Best Answer
If you have easy-ish access to the outside, I'd clean as much of the detritus away, patch the hole with plexiglass (perspex) and copious amounts of silicone caulk. Then install a triangular chunk of exterior plywood (painted both sides and all edges). Flash and caulk as much as possible. Attach as possible through the window frame.
On the interior, more plexiglass and caulk to seal the interior side. Then a skin of painted (both sides, all edges) exterior plywood (preferably with a smooth face) all the way across the window. Attach as possible to the window frame. Attach a bit of molding at the bottom if there's a gap you dislike. Caulk the heck out of it in an attempt to keep moisture from passing through.
For what it's worth, vent fans like this have a reason for existing. Everything above could be tweaked to allow for the install of a new unit. (Just remember where the hole was.)