[smoothie.]

Originally Posted by inv4zn

Dual hose by design are better/more 'efficient', depending on your definition of efficient.

Both systems bring in hot air from the room, cool it down, and expel it back in the room. The heat is exhausted outside. The difference is that dual hose units also draw air in from the outside, which exclusively cools the condenser. Because of this, air from the room goes into the room, and air from the outside goes back outside, resulting in a neutral pressure system.

Single hose units, because it's taking air from the room, but some of it is being spat outside through the hose, creates negative pressure. Which means it's going to draw air from somewhere else, most likely hot air from the outside, resulting in 'poorer' performance. So it's taking air, cooling it down, some of which gets exhausted, and then you're cooling it again because it's getting drawn in.

That's a quick summary - but there are studies of single hose units outperforming dual hose units either because of better design, etc. For a similarly rated AC, dual hose will cost more, yes - but not all dual hoses are more expensive (or better) than all single hoses.

Now, all that being said, if it's hot as fuck and the only AC available is single hose, then fuck yes just get that one. I see people on RFD be like I'm just gonna swelter in the heat because I can't get a dual hose one. That's just silly.

I have the new dual hose costco, and a 12K single from costco a few years ago.

When the heat was at it's peak, the dual hose was blowing much warmer air than the single hose. Usually, the dual hose room is cooler, but when its 45 outside.. different story.

Operating temps are a thing.