Review: Windmill AC

My house doesn’t have central air conditioning. Every year, during the swampy weeks of summer, I wrestle a loud, enormous, awkward, ugly air conditioner out of the bottom of my hall closet. I wedge it into my children’s bedroom window, wince every time I turn it on, and check the forecast every day to see when I can stow it again.

Last summer, a direct-to-consumer startup called Windmill sent me a test unit of its air conditioner. Before I could write a review, it sold out, and projected shipping times for preorders were delayed by more than a year. The company is finally accepting preorders again and now sells directly through Home Depot. If you need to cool down a bedroom or playroom, I suggest jumping on it. It works, it's easy to install, and it’s reasonably priced.

The best part? It's so attractive that I just realized I left it mounted for a full year without counting down every second until I could remove it. That’s probably the best recommendation I can make.

Air conditioners commonly measure power in British thermal units. For every square foot of living space, you need about 20 BTUs, while adjusting for factors like how high the room’s ceiling is, how much sunlight the room lets in, and how many people occupy the room and for how long.

At 8,300 BTUs, the Windmill is on the weaker end of the spectrum. That makes it a good size and power capacity for my kids’ 10- x 15-foot bedroom, especially since my children are still pretty small. It’s not powerful enough for a living room, but its price is very reasonable. At $395, it’s still cheaper than its much uglier competitors, like the LG unit it replaced for us.

You’ll need a sliding, double-hung window, with a height opening of at least 14 inches and a width opening of 23 to 37 inches. It weighs about 60 pounds, which surprised me, because I didn’t have any trouble lifting it to install it. The company's clear installation guide says to budget about 45 minutes for installation, but it took me less than 15, even accounting for the time spent cutting and putting the insulation in place.

You’ll probably first notice how the intake is on the front panel of the Windmill, and outflow is through the top. I really appreciate this design. You can’t aim cold air directly at your sweating torso, but it seems to circulate the air faster and lets us use the bedroom space more efficiently. My daughter’s craft table is directly under the window, and the Windmill doesn’t blast her in the eyes or blow all of her colored paper hearts away.

The unit’s controls are located on the top, and they're several tiny, labeled buttons beneath a fadeaway LED panel. You can either set the temperature automatically, or you can set the fan speed and mode manually, whether that’s Cool, Fan, or Eco (somewhere in between). There’s also a tiny remote, but my kids and I lost that almost instantly. It does support Google Assistant or Alexa for voice control, but I found myself using the app on my phone more often, especially since I usually turn off the unit remotely after the day cools off.

Temperatures went up to almost 100 degrees Fahrenheit last summer, but the Windmill AC kept my children’s bedroom at a pretty consistent 68 degrees. It worked so well that I occasionally left the door open for my poor dog to cool off in the hallway.

I long to rip out the air conditioning unit every year because they’re horrifically ugly and bad for the environment, in more ways than one. They’re energy-intensive and loud, and the vent for our air conditioning unit is about 3 feet away from my neighbor’s window. Giving my children crisp, refreshing breezes means pointing loud, hot air at someone else.

The Windmill is much better-looking than other air conditioners. I can’t do anything about the loudness—even on the lowest setting, I still measured it at about 60 decibels (which is as loud as a conversation in a restaurant). However, Windmill has made other sustainable changes, including the use of a new type of refrigerant. 

That was prescient. In 2020, Congress passed the American Innovation and Manufacturing Act to phase down the use of hydrofluorocarbons, or HFCs, which deplete the ozone layer. Windmill’s refrigerant, R-32, has far fewer HFCs than the refrigerant it replaces, the commonly used 410a. The company also partnered with the nonprofit Pachama, which uses company credits to support forest management projects around the world. And the appliance’s end of life is also accounted for: A partnership with Earth911 means Windmill owners are connected with a nearby recycling facility.

Steep environmental costs for a grotesque and awkward appliance can seem like a disproportionate price to pay for a few weeks of relief from stifling heat (you do have alternatives!). But the average daily temperature is climbing every year. Especially with dogs and small children, using an air conditioner can become a matter of safety.

The Windmill AC isn’t nearly as quiet or innovative as other air conditioners we���ve tested, but it's more environmentally friendly, and I don’t have to go through the rigmarole of installing dingy insulation in my children’s bedroom window every year. If you're going to need to cool off this year (and you probably will), it's worth trying to get one of these if you can find it in stock.