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Can A Window Air Conditioner Be Installed Sideways? (7 Reasons)

Can A Window Air Conditioner Be Installed Sideways? (7 Reasons)

A window air conditioner is a wonderful contraption but as with any piece of electronics, there are a lot of Do-s and Don’t-s with it. Say you have an overly narrow window that your AC doesn’t normally fit on but it would fit if you turn it sideways at 90o – would that be a good idea?

Can window AC units be installed sideways or are there some problems that may arise? Here are the 7 things to watch out for if you’re thinking of installing your window air conditioner sideways or in another irregular way.

Can window AC units be installed sideways?

Technically, it can. But that’s not really the right question. Instead, we should ask whether a window AC unit should be installed sideways – and the answer to that is a pretty categorical “No!”

Air conditioners are fairly delicate machines with lots of intricate parts that are meant to work in a certain way. While, technically, gravity doesn’t play into the manner in which an AC moves hot air from inside your home to outside, it’s still important.

So, even if your tape measure has shown that the air conditioner’s width is too much for your window but its height is just enough so that it’d fit if you turned it sideways between the window sills – you shouldn’t do that. Yes, the fans would still work and the screws won’t fall apart, but there are other factors at play too – we’ll go over them below.

What are the 7 reasons not to install your window AC unit sideways?

What are the 7 reasons not to install your window AC unit sideways

Credit: True Value

While a window AC unit can technically function for a while turned on its side, there are way too many things that can go wrong if you do this, especially as time goes on. So, if someone has given you the bad advice that it’s ok to just turn your AC to the side if it doesn’t fit properly otherwise, you really shouldn’t do that, and here’s why:

1. The airways can get easily blocked

The simplest but also one of the most significant reasons why you should never turn a window AC to its side is that you can get its airflow blocked very easily.

There can be some variation depending on what model you’re using but AC units traditionally have air vents on their sides and on their bottom. There are usually no vents on the top, however, because falling debris can easily block them. So, if you turn your AC to 90o, you’ll effectively force it to have exposed vents at the top.

Once those vents start having leaves, dirt, and other debris stuck on them, the AC’s airflow will be hindered and you can expect the unit to start overheating.

This first issue can be somewhat remedied if you install a cover above (but not directly on top of) the sideways AC. If done properly, this can prevent things from falling inside the AC’s air vents but it also is just more unnecessary work.

2. All the supporting components inside the AC are designed for standard positioning

While gravity doesn’t technically matter for how an AC functions, all the inside components of an air conditioner are typically arranged with gravity in mind. This is especially true for all the support elements – the grips and levers holding the critical elements in place.

In other words, if you turn your window AC unit sideways, a lot of its components may – and likely will – shift around a bit which can easily affect how they work. This will also vary greatly on the model as some may be safer in that regard than others, but it’s always a risk that doesn’t need to be taken.

3. The compressor’s lubricating oils will flow out and leave it to eventually burn out

On to an even more serious problem – the compressor oil is kept at the bottom of the compressor thanks to gravity. So, if you turn the AC sideways, the lubricants used to keep the moving parts of the compressor lubricated may flow out and leave it dry and working under intense friction.

Needless to say, something like that can easily lead to problems, up to and including the compressor exploding and a possible fire. Even if it doesn’t get to that, however, a malfunctioning or even just a poorly functioning AC compressor is still a very bad thing – it’s what keeps the refrigerant compressed and working as intended, after all.

4. Rainwater will easily get inside the AC

Another huge gravity-related issue that also has to do with the air vents is that leaves, dirt, and debris aren’t the only thing that can fall into the ventilation grates – rainwater can easily fall there too. And, once it does, it will go all over the AC unit’s gears and cause all kinds of malfunctions.

That’s because, while rain falling on a properly-set AC unit is harmless, if the inside of the machine starts getting flooded, it will go out of order very quickly.

And, as above, just blocking the vents isn’t a good idea as that’d stop the airflow. Again, you can try to build a cover above the vents (at least a few inches above them) but that’s extra work that wouldn’t be necessary if you just set the AC unit properly and not sideways.

5. The AC’s condensation won’t drip properly and may damage the AC

Yet another issue is that there is usually some water inside the AC unit too – the liquid droplets from the condensation that forms on the evaporator’s coil. Ordinarily, those droplets are meant to just fall down into the condensation pan at the bottom frame of the AC unit and then flow through the condensate drain line and out of the AC.

Needless to say, if you turn your window air conditioner sideways, that whole simple system goes out of whack. Instead of dropping at the bottom and flowing out of the AC, the droplets created from the vapor by the evaporator coil will drip onto other parts of the AC units, will gather where they are not supposed to, and will eventually damage the AC just as rainwater would.

6. You may void your window AC’s warranty

Onto a problem that won’t necessarily damage the AC or your home but your wallet – if you turn your window AC unit sideways and something goes wrong, your warranty will likely be voided.

That’s because most warranties explicitly say that they only apply if the machine has been “used as intended”. So, as no window air conditioner is intended to be used sideways, even if the thing that’s gone wrong has nothing to do with the AC’s positioning, the warranty will likely still be voided.

7. There are sideways window AC models you can simply use instead

Lastly, #7 isn’t a problem that may arise but another very simple reason not to turn your AC sideways – there are plenty of modern units that are narrow enough to fit any window anyway.

So, if you’ve got a narrow window that makes the installation of your current AC unit inside the window framing difficult, you can just replace your current unit with a new one. Yes, some money will usually be involved but, assuming that your wider AC unit is operational, you can probably sell it to raise the funds for a new one.

The units cited most often as ideal for narrow windows are casement windows air conditioners. A casement window air conditioner is made specifically to fit in the vertical space of a narrow window. Aside from that, however, a casement air conditioner is an AC like any other and will function as well as expected, assuming you’ve got the appropriate model for your window and your home.

In conclusion

In essence, there’s a reason why it’s always wise to follow the instructions of your electronic appliances, whether they are in the kitchen or hanging from the window. AC units may seem “simple” if you know a bit about how they work but they are also very potent instruments that can not just malfunction very easily when they are misused but can malfunction quite badly and spectacularly too.

So, as convenient as it may seem to just rotate your window AC a bit so that it’d fit better, that’s really not a good idea. The much smarter way to go about it is to just install that AC unit somewhere else or to just sell it and get an AC unit that’d actually fit your window properly.