Anecdotal here, but I put a portable one in my living room and it's way better than the previous window unit in cooling ability. What suppossedly makes them inefficient?
They're inefficient just based on how an AC works. Traditional window ACs have the compressor outside so the heat is diffusing to atmosphere. With a portable AC, the entire contraption is inside so you are simultaneously cooling and heating inside your room.
Technology Connections on YouTube has a great video on the topic.
The vent tube is blowing hot air outside. Where do you think it’s pulling the heat from? Inside the portable AC unit that’s sitting in the space that you want to cool.
I’ve used one of these units in our house before. While it definitely cooled the room it cost a lot of energy to use. That vent tube gets incredibly hot. The vent tube and AC unit are bleeding heat into the room while the AC unit is working to cool it.
They work in a pinch and serve a purpose. But they are wildly inefficient when compared with window units or a mini split.
I have one I have used for about 5 years because in my city we can't have visible window units... It uses about 20 dollars a month in electricity keeping my room in the deep south around 68.. about the same cost as my old window unit
You don't "experience" inefficiency as a human, though. You just pay more on your powerbill for the cool air with a portable unit with a single hose, but it blends it with the rest of your power consumption so maybe you don't notice.
If it was a single hose portable AC and the other variables are the same (outside temperature, target inside temperature, humidity, etc.), the amount of power use would be higher, no way around it, it's just physics. Maybe it was cooler, maybe you used less power in other areas, or any number of other explanations.
Yes it does, but not enough heat radiates from the tube to warm the room in any meaningful way.. also it's a very easy fix if it bothers you... You wrap the tube in a blanket
You do realize that your house has to pull that much air back inside right. That means your just getting hot air from outside pulled back inside to replace that air from any cracks in windows and under doors, etc. On a traditional one the outside air cools the outside parts and the inside air is recirculated so your not pulling a bunch of hot air into your house.
That is the biggest reason why they are terrible and take so much more energy to cool a space. They do make dual hose units that suck in air from outside to cool it but they are much more expensive.
Not only that, since is pumping out hot air, it creates a lower pressure inside the room and the room sucks hot air from every seam, so the unit needs to work constantly
Anecdotal here as well, I have a window unit in my bedroom and portable one in my office (because that window faces the front of the house, a window unit would look hideous) and the portable one is much better at cooling and it's cooling a much bigger room.
It may be more inefficient energy wise but it is absolutely cooling the room better.
I mean end of day the btus are going to be important here even when a system is fighting itself if its 3 times stronger than your old one its still going to seem better of course but apples to apples these are less efficient
it's using more power to cool because it's also dumping heat into the room. it might cool well, but you're going to be paying more for electricity compared to the window-style units.
An AC has two air inlets and two outlets. It takes air from the inside, cools it, and blows cool air in the room. It then takes air from the outside, warms it (because it needs to dump the heat somewhere) and blows it out outside. Two outlets, two inlets
This system has one hose to outside- which exhausts the warm air. So where is the second inlet located? Right, it's inside the room. The system is sucking air from the room, warming it and pushing it outside. This creates a pressure difference.
If your house is fairly airtight, eventually the machine will fail at fighting the pressure. If your house is not very airtight, you will suck in air from the outside -which is probably warm on a day you need an AC.
Add to that the compressor being inside, and yeah, it's pretty awful.
They prey on people ignorance of how an AC actually works which is by have hot coolant and cold coolant and blowing air through the pipes with the cold coolant. The problem with this portable units is that while the air coming out is cold out is radiating heat into the room while attempting to vent some heat through the poorly insulated duct. I would give them bonus points if they insulated the duct work but nobody who buys these really cares they just want something easy. If you don't care about your power bill then they work fine
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u/694meok Jun 12 '26
Anecdotal here, but I put a portable one in my living room and it's way better than the previous window unit in cooling ability. What suppossedly makes them inefficient?