Can I vent a portable air conditioner thru a wall sleeve? Will it vent properly? I have no air conditioning and don't want to spend a ton on a in wall air conditioner..
Do you already have a wall sleeve installed? if so you could vent a portable ac through it but most of the time they are designed for a window unit so it is the typical small rectangle wall sleeve I would recommend finding an window unit for it. That will work a lot better in the long run and should be cheaper to buy.
If you are thinking about installing a wall sleeve it would be perfect ventilation for a portable AC if you already have one.
I cannot see any problem putting the exhaust tube through a wall sleeve. I have seen crude use of an open window to put the exhaust tube through (closing the window onto the exhaust tube to hold it there) which to me is not as efficient.
As long as the exhaust tube fits inside the aperture it will be adequate for the purpose.
You can exhaust a portable through the wall but remember you need fresh air to be able to enter the home. Many newer homes are sealed quite well and pushing the hot air outside with out a vent to allow air to enter pulls hot air from the attic access in many cases. I have had home owners say the air will come in the bathroom or kitchen exhaust vents but both should have back draft dampers that prevent air from going backwards. A chimney usually will allow enough air entrance but this can cause odors in the home. If your furnace hose a make up air or fresh air port it would be fine to exhaust the portable through the wall. Make sure to check for live electrical in the wall prior to drilling (many stud finders have a live circuit detector and you really don’t want to drill through a stud either.
If it's an apartment shouldn't the landlord fix the ac? Have you thought about just buying a window ac and putting it in the wall sleeve? You can probably get a window ac for the save price, or close, as a portable one.