Right. I confused evaporative coolers and AC for a moment. Thanks.

Using a portable -one hose- AC give me about 5 degrees delta in half my small house during the EU heatwave, in my case improving on passive cooling by multiples, so your last sentence just sound like ' I've never felt the effects of portable AC' to me. probably pretty common in the US, but EU houses often dont come with AC preinstalled.

I get that it's a dumb system, and I even knew before I bought this one hose monstrosity, but it's what is available to us here right now, and the fact that a split ac or window ac or 2 hose airco system (there was 1 model available to me locally, and it was sold out) is way more efficient doesn't magically make the one hose version work bad. It still uses the compression cycle for refrigeration, which is very powerful even when used inefficiently.

It is a portable AC unit.

I see portable ACs with a single hose as single room ACs. The room with the AC is cooling and pulling air from the rest of the house. That air is being replaced by outside air in those rooms.

But yeah, passive cooling is always good to do. Even with the best AC.

I have added a second hose to my portable single hose AC. Just a hose that is "hanging" against the input part of the AC so if there is negative pressure, the air will get sucked in directly into the AC.

What a weird statement to keep repeating when it has such a big exception. "ACs don't do X unless its one of the most common types of AC."

ACs clearly do X, just not most of them. A lot of them explicitly do exchange air with the outside, because single hose portable types are widely used everywhere. They aren't ideal, but they are very common and are indeed "AC."