Portable Air Conditioners - Why you shouldn't like them

Air

conditioners

are great. *awkward pause* But there is an increasingly popular variety of

them

that, figuratively and literally, suck. Those would be... these bundles of joy. Portable air

conditioners

seem to be taking the world by storm, or at least they have taken the air conditioning island of hardware stores by storm. But are they good? Do these cold manufacturing machines have what it takes to usurp the traditional window unit? No. Portable air conditioners are actually kind of… bad. Now it's not that they don't work! And some of

them

aren't as bad as most. Plus, they can be really useful.

This one does its job precisely because the window it vents out of is not really suitable for holding a window unit in place with any sense of confidence. And I know because I tried. Yes, this here is the symbol of my shame. The air conditioning that was never meant to exist. But lucky for you I didn't return it because it will be a great visual aid! Now, in this video I'm going to argue that if you need an air conditioner, you should lean towards these simple window units and stay away from those modern

portable

units *if you can*.

And to know why, we need to learn a little about air conditioning. Air conditioners are mechanical devices that collect and concentrate thermal energy to transfer it from one place to another. The cold air they create is, in fact, ordinary air that has had its thermal energy sucked out. And of course, we can't just repress that energy (although it would be great if we could figure that out), but instead move it somewhere else, usually outdoors. And inside every air conditioner you will find three essential parts that make that happen. This is the basis of almost all air conditioning and refrigeration systems currently in service.

The black cylinder contains a compressor that squeezes a gas called refrigerant into a small space, decreasing its volume and increasing its pressure. The high-pressure gas, which has now become quite hot thanks to the fact that it has just been compressed, travels through these pipes to the second key component; the condenser. The condenser is a heat exchanger designed to cool that hot gas as quickly as possible. Densely spaced fins increase its surface area to speed up heat transfer, and a fan helps speed it up even further by blowing air across the fins. Since the coolant is now pressurized, its boiling point has increased.

And in fact, its boiling point has increased so much that once we lower it to about 130 or 150 degrees, it will condense into a liquid. So, as the hot gas runs through all these pipes and its thermal energy is transferred to the air, it slowly turns into a liquid, releasing a ton of thermal energy as it does so. Now this is where the magic happens. That liquid is retained by a metering device, such as a thermal expansion valve, to keep pressure high in the condenser and limit the amount of liquid refrigerant that can pass through. This basic air conditioner uses a capillary tube, a long copper tube with a very small internal diameter, to restrict the refrigerant and thus limit its flow.

But once it gets to the other side, it's in a second heat exchanger, called the evaporator. This is functionally identical to the condenser, except the internal pressure here is much, much lower thanks to the suction created by the intake side of the compressor. Once inside, the refrigerant can relax and its boiling point suddenly shoots way down, as in well below zero territory. And that means it will boil (or evaporate) spontaneously because, well, it's too hot to remain liquid. But to change phase back to gas, it needs to get energy from somewhere. And fortunately, the evaporator fins help it absorb energy from the room and the effect is that the room cools down.

In fact, the thermal energy inside the room is used to heat the refrigerant as it evaporates. This may be a little strange to think about because we like to think that the evaporator cools, and it does, but it cools because it extracts heat energy from the air into the refrigerant inside. Cold is actually less concentrated thermal energy, and since heat likes to go to cold places to spread, it naturally finds its way (with the help of a fan). Once the refrigerant has absorbed as much energy as it can, it re-enters the compressor where the cycle begins again.

Once it is under high pressure, it will be able to condense back into a liquid, releasing the energy it just absorbed to the outside air through the condenser. Now, I don't want to get too deep into the physics of how this works, or talk about what makes refrigerants special and why they have been and continue to be a notoriously difficult set of chemicals to deal with, so all I really need is your aid. What you need to know for this video is that there is a compressor, a hot side and a cold side. If we are cooling a room, we want the hot side to be outside and the cold side to be inside.

We can then move heat energy from inside the room to the outside air, cooling the room. So let's take a look at where these components are when the window unit is operating. When resting on a window, most of the machine is actually outside the space it is cooling. The compressor and condenser are outside, and thanks to the generous amount of polystyrene insulation, we get a pretty good thermal barrier. When cooling, none of the real air in the room goes outside: only the refrigerant and, therefore, the thermal energy it absorbs, goes outside. This maximizes efficiency. If you have a central air conditioning system, you probably have what is called a split system.

Here, the compressor and condenser (along with a cooling fan) are contained in a single unit that sits outside, and copper refrigerant lines enter the building to a separate evaporator located in an air handler or built into a oven. See? It is a split system, since the evaporator and condenser are separate. These systems are highly efficient, with the entire hot side located outside and away from the living space, and only a small hole in the home's thermal barrier is required to move the refrigerant in and out. Alright, now let's take a look at a

portable

air conditioner.

You may notice that the entire machine is inside. That means that not only is the cold side in, but the hot side is also in. Good. That's not cool. We want the energy absorbed by the evaporator and released in the condenser to come out somehow. So what do portable air conditioners do? They draw in interior air through these vents, blow it through the condenser to cool it, and then push it out through that hose. That last sentence is very important. They suck in air through these vents, air that they have just cooled, mind you, and expel it outside.

That sounds pretty stupid, just at first glance. Now, it's not that it doesn't work. If they didn't work, they wouldn't be as popular as they are. Also! Two-hose portable air conditioners, which draw in *outside* air to cool the condenser and then exhaust it in two separate hoses, are available, but they are an increasingly rare part of the portable air conditioner universe and the vast majority on sale. They are single hose units like this one. So if this machine relies on drawing air through these vent slots to cool the condenser, and then has to exhaust the now hot air outside, that means not only is it sacrificing some of the cold air it just generated, but You are also creating a low pressure environment in any space you are in.

Now the air pressure outside the room is greater than that inside. And that means outside air will come in through the walls to replenish the air that just left. You can't just blow the air out of a room without it being replenished somehow (otherwise you'll be in a vacuum chamber and I advise you leave as soon as possible). And what replaces it is ultimately the hot air from outside that you're fighting. Genius! And that is why we are at the center of this issue. Single hose portable air conditioners will always be significantly less efficient than a window unit because they don't just extract heat energy from the room.

They are also releasing the air. In fact, if you go to a hardware store and take a look at a new range of portable units, you will often find that they have two cooling capacities listed today. Because? Well, because newer testing methods are taking into account the losses caused by this hose, while the unit can technically move 8,000 BTUs per hour, thanks to the hot air it's pulling in (as well as its own cold air, is blowing again) it actually only moves 6,000 BTUs per hour. So basically it's 25% less efficient. But it's actually much worse than that! This little 5000 BTU window unit draws 455 watts.

If we take a look at this portable 5500 BTU unit from LG, you will see that it consumes over a kilowatt. That's more than double the input power needed to generate just 10% more cooling. A window unit that consumes that much power can produce about twice the cooling capacity. So yes. Eek. Now, I'm not here to say that these are terrible devices and that you're a fool if you have one. Because I'd call myself a fool twice if that were the case. But I will say that generally this should be your last resort. If you have the option to use a traditional window unit, take it.

It is much more energy efficient and will cost less to run. And yes, I understand it. They are ugly. They block your view from the window. They are not exactly attractive from the outside either. But they are not only better in energy efficiency. The air conditioners make noise. They are noisy because they are mechanical devices, with a compressor that hums and two fans that move the air. In a traditional window unit, the compressor and one of the two fans are outside. Thanks to this thermal insulation, great acoustic insulation is also achieved. You will certainly notice a difference when the compressor is on and when it is not, but it is often quite subtle.

Especially since, as is the case with many window units, the same motor drives the interior fan and the condenser fan, so the only part that turns on and off is the compressor. And of course, split systems are even quieter because the noisy parts are not close to the living space. Compare that to this thing. Not only is the compressor now inside the room you are trying to work or sleep in, but so is the condenser fan. The result is that it is not as noisy when only the circulator fan is running. But when your thermostat calls for cooling, it gets much, much louder!

Suddenly the compressor kicks in (which is again inside the room) and a second fan turns on to blow heat out of the condenser. It's a good thing the condenser fan turns off when it's not actively cooling, as otherwise it would suck even more air from the room. But it means there is a big difference in noise levels between not cooling. And cooling. And if you try to sleep in the same room as one of these, you'll have to put up with it going from fairly quiet to very loud and back again again and again. This is a cheap in-house brand unit from that place where you save a lot of money, so I wasn't expecting it to be quiet, but I also have a more suitable unit from LG which, while a bit more stylish in the way it handles the transition from cooling to not cooling and vice versa, is still much noisier when cooling.

I'm a pretty heavy sleeper, and even for me it can be a challenge to ignore it and fall asleep. And another thing to consider is that while window units steal more of your windows, they don't steal your space. The portable units are not small and cannot sit flush against the wall thanks to the hose, so be prepared to rearrange some furniture. And by the way. That hose? It's hot! That heat energy you just concentrated isn't going away without a fight, and since this hose isn't insulated at all, some of it goes right back into the room.

Fantastic. But I admit it. Portable air conditioning units are useful. Really useful. They don't need proper installation like a window unit does (which is pretty annoying, I might add). They can be easily moved from one room to another thanks to the wheels they have (that's why they are called portable). And they fit window types that couldn't otherwise accommodate an air conditioner, such as vertical windows or even patio doors. You can even run them through a small dedicated vent if you wish. But unfortunately, their single hose design makes them, honestly, a terrible device when it comes to efficiency.I would like to see more dual hose units available for sale.

They will still have the disadvantages of noise and space, but at least they will regain much of their efficiency. Last year I tested a portable mini-split system, with a separate outdoor compressor and condensing unit, and an indoor evaporator unit connected via a flexible refrigerant hose. Unfortunately, my unit leaked refrigerant and stopped working after a few weeks. It seems like a common problem, but let me tell you, it was wonderful while it worked. Silent, efficient and effective. I would like to see this product developed more, but I also understand that it has many more limitations than even a window unit.

Unless you want to get creative with some type of exterior wall mount, this is limited to a ground floor room or a balcony room or something similar. But anyway. If we are going to keep using these things, can we get more dual hose units? I understand that they are less flexible, particularly with vertical or narrow windows, and so are probably less desirable, but hopefully, as more people become aware of the energy losses caused by continually blowing air out of their home, we will see more demand. . Still, if you are looking for an air conditioner in a situation where a window unit could work, you are better off going with the window unit.

Contrary to what you might think, portable drives are certainly not an improvement. Apart from its portability. That's very good. Thanks for watching and I hope you found this video as interesting as a properly charged air conditioning system. I want to explore air conditioning a little more because I find it fascinating. The way we exploit the physical properties of certain gases to make thermal energy move where we want it to go is mind-blowing. Oh, and by the way, not all coolants are crazy, complex chemicals. Some small refrigerators and air conditioners are beginning to be charged with propane.

Propane, also known as R290, is becoming an increasingly common refrigerant thanks to its abundance and relative environmental friendliness. Unfortunately, it is also flammable, which makes it a bit difficult to maintain and unsuitable for larger units that need a lot of refrigerant. But especially for small, cheap units like these, which will probably just be thrown away when they break down rather than serviced, it's a great opportunity to use it. However, this machine, although loaded with a flammable refrigerant, uses difluoromethane or R32. Of course, thanks to everyone who supports the channel on Patreon, with a special thanks to the great people you see scrolling up on your screen.

If you want to join these people in supporting the channel, there is now a new benefit! All users have access to Patreon's exclusive Technology Connections Discord server. So if Discord is your thing, you can join these other people by linking your Discord account to your Patreon account. And as always, early access to videos, occasional (very occasional) behind-the-scenes videos, and other Patreon-exclusive goodies are also available to you. Thank you for your consideration and see you next time! ♫ smooth and icy jazz ♫ ...the cold air they create is actually ordinary air, huh. Ugh, ugh, ugh, ugh. I... this tone is completely wrong.

Well... maybe move at a pace that makes sense. Yes, that is misspelled. OK that's fine. And now I'll record that line as written! Or at least they have taken away the air conditioning hardware island… the hardware! Arghh...no. Air conditioners make noise... I should move this again. The coldness is actually just less concentrated thermal energy, and it feels like… Augh! Sint. From the heat! FROM the heat! It's been wonderful ever since! Since it is the word. From.