Submitted by chinawcswing t3_y277vw in BuyItForLife

I've read on /r/bifl that if you are going to purchase a portable air conditioner, you should buy a dual-hose system instead of the single hose system. The reason is that a single-hose system creates a pressure difference and results in all the hot air outside immediately flooding back into your room as soon as you turn off the unit.

However, does something like this even matter if you live in an old apartment that has zero insulation? How much help would the elimination of this pressure difference be, given that the cold air inside your apartment is constantly being replaced by the air outside if you have no insulation?

The dual hose units are often twice as expensive as the single hose units.

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Gah_Duma t1_is188s6 wrote

They're also vastly more inefficient because they're using the air that it just cooled to vent the heat outside. EIther way, it's bound to break down in a few years. I've purchased on the order of 20 units and not had one last more than 5 years.

If possible, use a window unit. Cheaper, quieter, more reliable, more efficient.

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chinawcswing OP t1_is1apdr wrote

Ya, I've had two of these units break in the last two years.

Unfortunately my apartment only has horizontal sliding windows and I have zero handyman skills.

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2lovesFL t1_is1jb23 wrote

I have a single hose portable ac. Its been fine for the occasional use to add cooling in the summer to a central ac house. the use more energy than a mini split, or standard ac.

my main concern was the condensation. if they needed to be drained or evaporated the accumulated water.

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pitterpattergedader t1_is28fah wrote

Super easy to make an in-window unit work with horizontal windows. A single metal bar cut precisely to length holds the unit in place, then you can use a sheet of plexiglass or double wall polycarbonate to fill in the remainder of the window. You can probably get the bar cut to length at the hardware store. The double wall polycarbonate can be cut with a utility knife. Have this in two windows, works great. Portable AC's should be made illegal for how inefficient they are.

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Muncie4 t1_is3n2if wrote

The hierarchy of AC units:

  1. Window
  2. Dual hose
  3. Single hose

Choose wisely. And BE SURE you buy the right size one as they have BTU/Square Foot ratings and many just pick the first one they see. And sweat like Mike Tyson in a spelling bee because they picked one too small.

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Funkasaurousrex t1_is3vv3d wrote

You are incorrect in thinking that the hot air outside immediately flooding back in when you turn it off.

When you turn on a single hose unit, it is CONSTANTLY bringing in hot air when it is in use. The air has to come from somewhere and if you are dumping the air from inside to the outside, it must be replaced with outside air to equalize the pressure. This comes from every crack in your house, every tiny gap, etc.

so sure you are blowing cold air around in the house but to do that, you’ve turned your whole house into a vacuum pulling in hot air from the outside. It’s pretty inefficient.

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SeaWeedSkis t1_iswuuf1 wrote

Due to the window configuration in our rental, portable A/C is pretty much our only option. It hit 115F last summer, so we're not willing to be without A/C. We have both a single hose model and a dual hose model. The dual hose model puts out more BTU's for less energy usage. The dual hose model is also able to send water out the exhaust hose, which is a significant improvement over the single hose model that has a little "pee tube" that we leave in a bucket that has to be emptied periodically. The bucket has overflowed more than once when we weren't paying close enough attention.

If an in-window unit isn't an option then get yourself a Whynter dual hose model. They're expensive, and they take up a lot of floor space (hoses out the back can't make a sharp bend, so expect the unit to sit a few feet away from the wall) but at least they work regardless of your window setup. We've had our single hose model for, oh, probably around 7 years now and I think the dual hose has seen us through 4 summers now.

Make note of the square footage they'll cool. We have the single hose 8,000 BTU model in a bedroom and a 14,000 BTU dual hose model in the main part of our small home. (I'm not sure on square footage but it's probably somewhere around 1,000 sq ft and we often close off the second bedroom to reduce cooling needs.)

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leadfoot9 t1_itbul2n wrote

>The hierarchy of AC units:
>
>1. Window
>
>2. Dual hose
>
>3. Single hose

Well, you forgot the various higher-tier kinds that need to be permanently installed. Traditional central ducts, ductless mini-splits, radiant cooling, etc.

Also, I'd argue that opening a window and turning on a fan is just as good as portable AC with hoses in many climates while being much, much cheaper.

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leadfoot9 t1_itbv1rz wrote

I just thought dual hoses were slightly less bad because they didn't let the ambient and hot air mix in the same hose, which allows them to move air more efficiently. I don't see how pressure has anything to do with it. All air conditioners create pressure differences. Meh, I just read an article saying that's wrong. Not a well-written article, but I'll withhold my judgment on that.

All portable AC with hoses are garbage. Dual hose is only slightly better. If it costs twice as much, you're much better off buying literally any window unit that you can get to fit.

If your apartment has walls, then that's still more insulation than the hoses have. Speaking of which, if you do end up making the unfortunate choice of buying one of these, at least put some insulation on the g*****n hoses!

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