I don’t have an ac in one of the small rooms in the house. It was blocked up using wood previously. Seemed to work, but now I have started to smell what is coming out of a vent from a nearby restaurant.
in our house the landlord put red bricks and covered them with plaster, its non permanent, in the sense you can break it with a heavy hammer if needed. but its more permanent than a piece of wood.
That is what the ac guys put around the other air conditioners in the house. I’m just worried if smelling the restaurant means I’m getting slowly polluted to death.
Wood should work just as well as the plastic sheets (and better sound insulation) but you need to fill any gaps with something to block smells. I once used that expanding foam from a spray can, which blocked the pigeon smell and sound well enough. Use duct tape around all the seams to prevent the foam expanding inwards.
edit: it’s actually not that temporary, and it’s a bitch to get off later, so be warned. But it works really well at both sound and smell insulation.
We had a “change glass” man do up a window we had in Taichung years ago. Ask your security guy if he knows of a similar guy. Came up, measured and cut the glass and set it in. Non-permanent as it can be easily removed.
If you just silicone plastic sheets alone, a typhoon can rip that right out. Buy some cinder blocks and metal tie wire. Use wire with silicone connected to blocks. Fast and cheap installation/removal.
Edit. Most people also dont store important things around such openings. The relity of earthquakes, winds and rain leakage are the usual logic. Good place for an unimportant cloaet or similar. I wouldnt keep breakables, beds, chemicals etc anywhere near said openings.
Perhaps just seal the edges with liquid silicone (or whatever you call the kind that comes in the squirty tubes)? It scrapes off pretty easily and cleanly if necessary.