It’s almost impossible to dislike LG’s Dual Inverter window air conditioner (or if you want to call it by its official name, the LW1019IVSM), especially with temperatures topping 95 degrees in New York City this summer. It cools down my bedroom incredibly fast, and it doesn’t get egregiously loud. It’s smart too. Before entering my apartment building, I remotely turn it on so I can walk straight into some semblance of bliss.  

OK, fine. I did have to go to the hardware store to install it, partly because my windows are weird. But once I got the heavy thing mounted, it blasted my woes away with icy gusts. 

The Ice Man Cometh 

It took me two days to install this AC unit. It’s my fault that I decided to mount it at 11 pm, but it’s not my fault that I realized soon after that I wouldn’t succeed without some equipment. The specifications call for double-hung windows of a certain dimension, which I have. But the center of the sill is like a deep canyon. It’s not flush with the inner sill, which meant there was no easy way to mount the included L brackets to keep it secure.

The fact that the instruction booklet has an included solution suggests that this is not an uncommon problem. So the next morning, I grabbed some plywood from a nearby Home Depot, sawed it to the right shape, and plopped it in to create an even surface. I screwed the L brackets onto the plywood and lifted the 63-pound thing into place with the help of my partner.

The rest was relatively easy. The manual is fairly detailed and easy to follow; just be prepared for possible window shenanigans. If you find yourself at the local hardware store, you can also pick up a metal bracket instead. The AC will sit much more securely (it also might be a requirement in cities like New York), and you won’t have to drill any holes.

LG includes a good amount of foam and padding to seal any gaps around the AC unit, though don’t expect the same level of sound blockage as when your window was closed. Noise will leak in (thanks, New York). It doesn’t beat the soundproofing I experienced with Midea’s U-Shaped air conditioner, where the window goes down much further, creating a smaller gap.  

Cool Party

What exactly does “Dual Inverter” mean? A regular AC uses a single, motor-driven compressor to remove hot air from a room, cool air in a chamber, and pass heat outside. Usually, the AC senses when the room is too hot and the compressor ratchets up to the max level, then shuts down when the room hits the right temperature. 

However, the LG AC has twin compressors and chambers, which allow it to tweak its output. If a room requires only a certain amount of energy to cool a room, the motor doesn’t need to ratchet all the way up to work. That makes the unit faster, quieter, and more energy-efficient. According to Energy Star, this unit uses 27 percent less energy than the US federal standard, and it did successfully maintain temps once it cooled the room. 

What you probably want to know most is how well it cools, to save you from the next heat wave. The answer is very, very well. On a particularly sweltering 94-degree day, this LG unit brought the indoor temperature from around 84 degrees to a comfortable 73 within an hour. 

Photograph: LG

I do have to note that LG sent me the 9,500-Btu (British thermal units) model, which is rated to cool a room of around 400 to 450 square feet. Unfortunately, I was only able to test it in a room about half that size—though when I left my door open, it cooled my hallway and bathroom reasonably well too. (You can see what Btu rating you need based on your room size here.)

The fan is strong. You can choose between three fan strengths, and I usually left it at the lowest setting. On the highest, I could feel the icy wind on my face more than 12 feet away. You can also adjust the louvers up, instead of just side to side, to direct air away from your face. That’s helpful, especially if you end up spending a lot of time in front of the AC because of your room configuration.  

Thankfully, it doesn’t get loud. My bedroom normally hovers around 42 decibels, which is a little quieter than a library. With the LG AC on, it revs up to 54 decibels, which is about as loud as a conversation at home. This isn’t as quiet as the aforementioned Midea AC, but it’s significantly quieter than most other air conditioners I’ve tried, all of which blared around 70 decibels.

That said, I would avoid using the Energy Saver mode at night. It cools the room down to the desired temperature and then shuts off. It’ll come back to life every so often to cool the room down again, but the sound it makes when it does this has woken up my partner and me a few times. It sounds like the propeller of an airplane starting to spin, or an old car failing to start. Not fun at 4 am. Instead, we relied on the timer and set it to turn off a few hours into our sleep. 

Hell Freezes Over

The only thing you’ll need to regularly do to maintain this AC is clean the filter. The light will turn on automatically after 250 hours of operation (around 10 days). You can just pop it out, wash it, let it dry, and put it back in. Just remember to press and hold the up and down temperature buttons to turn off the light, because the AC doesn’t automatically know if you’ve cleaned it. 

You can use the included remote or LG’s app to control it, but I preferred using my voice with my Google Assistant speakers (or through the Google Home app). It supports Amazon’s Alexa, but not HomeKit. Over the three months I’ve been testing this AC, it never once had a funky connection with the app or needed me to reconnect it to Google, which is usually standard practice with smart home devices. That means I’ve reliably been able to turn it on before I get home, so I can enter an icebox. 

Look, I know air conditioners aren’t eco-friendly, and if you’d prefer to skip it, you can check out our guide on how to stay cool without AC. But as the Earth continues to heat up, they can help us feel more comfortable during the hottest months, and in some places, cooling devices save lives. Dual inverter tech does make this unit more efficient compared to other ACs with similar cooling capacities. That makes me feel a little better when I stand in front of it, after wading through New York’s heavy summer humidity.