[rmay635703]

My ancient duplex has tall narrow windows that won’t fit a normal window AC which means portable AC with a hot air pipe going outside.

Tempted to try to improve its efficiency by wrapping the burning hot plastic pipe in the silver reflective heat blanket I have.

But more complex I have a large return vent to the wet basement right behind this AC unit.
Years ago my folks had curved vent covers that would sit on this type of vent.
I would like to vent and duct tape the floor return to the exhaust intake on the ac so the wet stinky air get sucked out of the basement cooling the hot side of the ac venting it outside

Air is cooler down there so it should also increase efficiency.

Any ideas what junk I might get to attach the floor vent to the ac uptake to the exhaust? Stuff I can easily source doesn’t handle the vacuum. Would want to get it airtight so it pulls the air only from the basement, other vents are closed or covered to reduce simply sending cold air into the basement directly