Single vs Dual Hose Portable Air Conditioners

In this video we discuss the differences between single hose and dual hose portable air conditioners. What are the advantages of dual hose ACs? What are the disadvantages? We end up finding that the number of hoses involved in the system does impact overall efficiency. But it doesn't impact the overall cooling capacity of the air conditioner to the extent that it's impossible for a single hose system to outperform a dual hose system. To the contrary, we find that there are multiple single hose systems on the market that outperform the best and most prominent dual hose options.

[TheArchaeus]

Edward Snowden got real serious about having a cool room to work in.

[BlueBetaPro]

Why are single hose units even legal, what a waste of energy, it would be like leaving the window open every time you turned up your thermostat, or down your AC for that matter, what idiots, those people should be fined heavily for even making them. If WV can be fined for not meting efficiency and pollution standards then these guys can certainly get fined for building this absolute garbage.

[johncalla]

Bizarre review. I had a 10, 000 BTU single hose PAC and it couldn't even cool down a 200 sf room. The amount of air it was evacuating was ridiculous. It was probably something like 200 cfm. At that rate the entire room's air is completely turned over in about 10 minutes. There's no way to cool the room. And since the cool out vent is in the proximity of the condenser intake fan and exhaust, the cooled air is the first to get evacuated out of the room. I don't even understand why they still sell these.

[sleeknub]

You can't really solve the infiltration air problem with single hose units, but you can pretty easily solve the issues with a dual hose unit by insulating the hoses and taping the joints.

[jdbridgeks]

This video makes it seem like the losses due to the way a single hose unit sucks out the air that it already used energy to cool to then cool itself, thus bringing in massive amounts of outside warm air is *remotely* close to the minor loses of convective heat from short 5 foot hoses and a couple extra leaks.

The inefficiencies of a single hose unit are *orders of magnitude* greater than the marginal increases in small heat gains from a dual hose system. I can't fathom why you would want to defend terribly designed single hose units, unless you are paid by their manufacturers to shill for them.

You should always purchase a dual hose unit, as that is the same operating principle as split units (traditional whole-home) and most American style "sit-in-the-windows" units.

[SomeSenseCommon]

There is one thing that this video fails to mention. It is my understanding that for the same SACC / DOE BTU, the single-hose units use a lot more electrical power than an equivalent SACC / DOE BTU dual-hose unit. For example, a 1200 watt single-hose unit produces 5200 DOE BTU, whereas a 1200 watt dual-hose unit produces 8600 DOE BTU!

[Dcc]

If you got a portable AC just for 1 room and always stays there, try and wrap the exhaust hose in as much duct insulation as possible. It makes a huge difference. It won't look pretty, but it works.

[MiguelAngel-hcdp]

Lots of talking, theories and explanations, but I believe you never really compared in "real life" a single hose vs dual hose. The amount of hot air that single hose sucks into the room is vastly more detrimental than the leaks and heat radiation from an extra hose, there is simple no comparison. Just close the room door and place you hand or foot in the joints between the door and the door frame and you will feel the air blowing inside in great amounts, so you are blowing out cold air all the time creating vacuum in the room, and then sucking in hot air all the time, so you really never end to cool the room, as the situation is equivalent to try to cool a room with the door open, we all know how difficult that can be. . And that is a unsolvable flaw on the single hose units.
Is true that outside air wont cool the condenser as quickly, but it does not really matter is this situation. Besides don't forget that windows air conditioners get cooled with the outside air, and sometimes even get hit by the sun directly and still work well. If you can intake enough air flow you will cool the condenser enough to allow him to work efficiently even with the outside hot air. Your statements are simply ridiculous. I believe you have some interest in promoting single hose units, probably from the brands you mentioned. I could send you the heat transfer equations and calculations but I don't have time for that. Even more I converted a single hose to dual hose and results were immediately outstanding, cooling the room lot lot faster.

[juniormencia]

in practice, these devices are good only for sleeping at night. I have a single hose and I adapted it for dual hose and ended the problem of negative pressure and waste of refrigerated air.

[sergiodjf]

...This not exactly quite the analogy but... we all are familiar with our car AC. If we want to cool down the cabin as fast as possible we usually close the fresh air intake (recirculation mode). That would have a similar effect as a dual-hose unit that keeps the warm outdoor air away from the room. Quite the opposite if we open the fresh air intake, it would have a similar effect as a single-hose unit, drawing unconditioned air to the room all the time.

[wagnery]

I have just confirmed that reality is completely opposite to this video. Replaced a single hose 10k btu SACC for a dual hose 10, 5k btu and the difference is huge. The single hose had the compressor on all the time when I tried to cool the bedroom to something around 18c, because the pulled outside hot air prevented it to reach the desired temperature. With the dual hose neutral pressure, it can keep it easily.

[toddhughes]

I don' t think that he understands refrigeration concepts. I have been a manager for 2 HVAC companies. A dual hose unit will always be more efficient. He tested one dual unit that is technically not a complete dual hose, as he admits. Once you seal and insulate both hoses it will be much more efficient. He also doesn't understand that a single hose unit is exhausting air that it has already cooled. Time for him to go back to school.

[tomascernak]

dude, check your physics, radiation power of hose with outside air is nowhere near numbers of thermal power of that same air itself. Also we can assume, that intake hose will have much lower temp gradient with room air temp compared to outtake hose.
Two hose system is vastly superior to single hose system in efficiency.

[Aethid]

Yes, two units with the same SACC will have the same "cooling potential" - but a dual hose design will do it whilst consuming significantly less power, and potentially while being a physically smaller and quieter unit. A single hose design will also heat up other parts of the house, by drawing hot air into them from outside. To claim that the two designs are the same because one of the stats on the box accounts for the fact that one design is shit, is highly misleading.

[CurtWelch]

Single hose units work well when you need to supplement a house A/C to help cool a single room that is too hot because it not only adds cold air to the hot room, but the circulation "problem" becomes an advantage! It assists in circulating cold air from the main A/C into the room that is too hot, and the make-up air being sucked into the house, will mostly flow into rest of the house, then be cooled by the house A/C before being sucked into the hot room. Single hose units help balance the A/C without having to add entire new ducts and a larger A/C to your house. So single-hose units are actually ideal when trying to cool down a hot spot in a larger building that already has A/C. But if you have no A/C in a house, and are trying to add A/C to only one room, like a bedroom, the single hose unit will just keep sucking hot air from the rest of the house into the room, instead of re-cooling only the bedroom air. A dual-hose unit is far better for cooling only one room in a building when the rest of the building is just as hot as the outside air. single and dual house units solve different problems.

[workingTchr]

Excellent explanation of this whole business. I'm a renter and can't mess with a traditional window AC, so I'm going to get a single hose portable AC and put it outside(!) next to the window. I'll put some kind of adapter over the main air intake and run a duct through the window to suck air in from inside the house and put a similar adapter on the cool air output and duct it into the room. Then it'll function like a regular window AC, no negative pressure will result, and there will be no hot ducts inside. My main problem is humidity (tropical climate) so I'm hoping the outside air will be enough to cool the condenser. At least now I kinda know what I'm doing.... Thanks.

[dherrendoerfer]

SACC is probably the worst indicator for a comparison between single and dual hose AC units. The main reason is that there is no test setup description available that fits the design. The cooling capacity at any given seasonal point is measured against a constant volume of air .. with a single hose unit that does not work, where's the exhaust air to come from ? So a few admissions had to be made, for example that the exhausted air is replaced by 'room temperature' air that has 'exactly the same' humidity as the test volume :-)
The second thing is that hose type ACs have no seasonal use cases, they mostly get stored away when not needed.
I modified a single hose to dual some time ago and measured the result. It's cooling performance dropped by about 10% because of the losses in the second hose and the higher temps of the outside air, but it's cooling capacity of the room volume of air rose by 40+ precent, simply because the room never filled up with hot outside air. Where the unit was running 100% of the time it dropped to a nice 30/70% duty cycle.
The point here is: the SACC value of a dual hose may be lower, but the suction effect of the single hose units ruins their actual performance while the SACC calculation ignores that effect.

[NIAtoolkit]

I'd like to see measurements from a dual-hose AC first with the intake hose connected and then with the intake hose not connected. This way we aren't comparing apples to oranges

[alanw.]

I have a dual hose and single hose air conditioner. The dual hose works to cool whatever room it is in. The single hose is only a spot cooler that I use in a small den that blows cold air on me when at my desk. Single hose is basically a fancy fan that only cools you down if you are right in front of it.

[ryanhenderson]

This guy obviously works for the single hose unit consortium! 🤣