I tested this wall-mounted, smart infrared heater for two months — and now I can’t imagine going back to a traditional space heater

The Boldr Kelvin isn’t your typical space heater. Instead, it’s a wall-mounted, radiant heater that you pair with an app to control or add to your smart home. Then when the weather gets warmer, it doubles as an elegant-looking piece of wall art that you won’t have to stuff into your closet until the winter.

Available in black or white and in a standard or large size, the Kelvin takes a very different approach to heating whatever room you have it installed in. While a traditional space heater uses a noisy fan to fill a room with hot air, the Kelvin uses infrared heat to warm people and objects instead of the air itself, which in most scenarios is more energy efficient. After testing it for the past two months, my favorite thing — besides its unique design — is how the radiant waves it emits instantly warms me up instead of heating the whole room.

While I’ve been very impressed with the Kelvin, it’s not without its downsides, with the biggest one being its price. At $399 for the standard 450W model or $550 for the larger 750W one, it is certainly an investment. Then there’s the fact that once you wall mount it, you can’t easily move it from room to room. Still, for those looking for a permanent zonal heating solution that’s safer than your standard space heater, it could be the perfect solution.

My Boldr Kelvin review will help you decide if this is the best space heater for your home and whether or not its elegant design and unconventional heating method is worth the steep price.

Boldr Kelvin smart infrared heater review: Price and availability

The Kelvin is available directly from Boldr on its website in either black or white. The standard Kelvin costs $399 while the Kelvin Large costs $550. Both come with all of the accessories you need to get it installed and a wireless temperature sensor that works with the Boldr app.

Boldr Kelvin smart infrared heater review: Design

The Kelvin sports a very modern design with no physical buttons or knobs as it’s controlled entirely via an app, though you can also use Boldr’s Klima smart thermostat if you prefer physical touch-based controls.

At 37.8 x 19.7 x 0.5 inches, the standard Kelvin doesn’t take up that much wall space once installed. When mounted horizontally it looks like a flush-mounted flat screen TV like the Samsung Frame and when mounted vertically, it’s closer to a mirror. In fact, thanks to its glass surface and glossy finish, it can easily be mistaken for a modern mirror.

The Kelvin has an IP44 water resistance rating, which means you can also mount and use it in your bathroom.

Regardless of whether you get the standard model or the Kelvin Large, they both come with a 5.8 foot long power cord that uses a standard plug. It’s attached on the back of the device and hangs down from the right side.

In addition to the mounting equipment, you also get a smart sensor in the box. It’s powered by two AAA batteries and has a hole in the center so you can wall mount it as well. The smart sensor reminded me of the one that comes with the Nest Learning Thermostat (4th Gen) and it works in a similar manner. Once connected to your Wi-Fi network, it allows the Kelvin to read the ambient temperature of the room it’s installed in and heat it to your desired temperature.

Boldr Kelvin smart infrared heater review: Setup

The Kelvin heater Boldr sent over for review arrived in a single large box. Once unpacked, I was left with the heater, the accessories needed to install it and the smart sensor. Boldr also includes a paper template which doubles as an instruction manual to help you get the positioning just right before you start drilling holes in your walls.

I like how the Kelvin comes with two sets of wall anchors: a traditional orange set and a grey set for drywall you have to screw into the wall. I went with a horizontal orientation and after drilling four small pilot holes, I inserted the grey drywall anchors before installing a screw at each corner.

Once this was done, it was just a matter of hanging the Kelvin on my wall in the same way that you’d hang a picture frame. Given its larger size, you’re going to want someone else to help you hang it as lining up the holes on its rear frame with the four screws can be a little tricky.

One thing you do need to be mindful of before you start the installation process is that the Kelvin does need to be close to an electrical outlet and that, due to the way the holes at the back are designed, it will shift slightly once installed.

With the Kelvin mounted on my wall, I set up the Klima thermostat Boldr sent over with it and downloaded the required app on my phone. You can also add the Kelvin to your smart home as it supports both Alexa and Google Assistant; I used an Echo Dot smart speaker in the same room to turn it on and off.

Boldr Kelvin smart infrared heater review: App

Available for both iOS and Android, the Boldr app features a clean and minimalistic design. There are tabs across the bottom for Home, Energy, Automations and Settings. In my testing, everything worked well without any issues.

The most interesting part of the app was the Energy tab. Once you add your electric provider and how much you pay for kilowatt hour, the Boldr app can then show you how much it costs to run the Kelvin each month based on your current and past usage. If you don’t know exactly how much you pay per kilowatt hour, the app comes pre-programmed with rates from electric companies around the world. Since my own energy provider wasn’t listed, I did just that.

There’s also an Automations tab where you can have the Kelvin power on or off to heat your room to a particular temperature based on factors like the time of day or when the room temperature or humidity changes. Likewise, you can also enable presence sensing using your phone’s location to turn the Kelvin on or off when you arrive or leave home.

Overall, the app was intuitive to use and its streamlined design as well as lack of ads or upselling was a pleasant surprise compared to some of the other smart home apps I’ve used in the past.

Boldr Kelvin smart infrared heater review: Heating performance

When you turn on the Kelvin, it only takes a few moments to start feeling the heat from its glass panel. Unlike with forced-air space heaters that need to warm up your entire room, this one feels more like the sun hitting your skin on a warm summer day. This is why you want to ensure you mount it close to where you’ll be positioned in the room.

I installed my review unit a few feet away from my couch as there’s a 10-foot sweet spot where you’ll feel the heat. Beyond that, the Kelvin will only slowly raise the overall temperature of the room.The standard Kelvin is rated for rooms up to 100 square feet while the Kelvin Large is rated for rooms up to 215 square feet. You can use multiple units in the same room.

The Kelvin can only be wall mounted for a reason: its glass panel gets hot to the touch. This is another reason why I mounted it horizontally instead of vertically. That way, my younger son won’t accidentally get burned by touching it. Besides its wall-mounted design, the Kelvin includes a number of other built-in safety features like overheating protection and Guardian Mode which lets you lock its temperature.

During the two months I spent using the Kelvin to heat our larger living room, it kept my family and I warm without overheating the room. Likewise, as it only uses 450W (or 700W for the large model) instead of the 1,500W used by most traditional space heaters, I wasn’t as concerned about turning it off to save energy. Instead, I turned it on when everyone got home and turned it off when we went to bed.

Given that the temperature here in Houston fluctuates quite a bit and can literally be 40°F one day and over 70°F the next, I didn’t use it everyday. Still, I was very impressed by how little energy it consumed when I did. For instance, in November after installing the Kelvin, it used 32.40 kWh which the Boldr app estimated cost me just over $6. Then in December when I had it on more frequently, it used 69.98 kWh to the tune of $15.

Overall, I was very pleased with how quickly the Kelvin could warm my family up on a cold day without wasting energy by heating the entire room. Another great thing about this heater is that since it doesn’t have a fan, it runs completely silent while in use. I did notice a small pop when turning it off but this is likely from the mechanical relay inside its power adapter.

Boldr Kelvin smart infrared heater review: Verdict

The Boldr Kelvin is as much a piece of wall art as it is a more permanent space heater alternative. It’s relatively easy to install if you’ve used drywall anchors in the past and it’s simple to get up and running once you do. The infrared heat put off by the Kelvin feels completely different from the hot air that traditional space heaters fill your room with and it’s a great option if you suffer from allergies due to its reduced air circulation.

Still, at $399 for the standard model and $550 for the large Kelvin, it is more of an investment over a space heater. Likewise, once it’s mounted to your wall, you can’t easily take it down and move it from room to room. However, if you’re tired of tripping over a space heater at night and don’t want to deal with the safety issues using one incorrectly poses, the Kelvin could be worth it.

Personally, I love how it looks on my white wall and the way it blends into the background. When I’m using it, it’s a near silent way to heat a single room and when I’m not, its highly reflective surface allows it to double as a mirror which makes even small rooms feel larger.

If you’re looking to cut down on the cost of heating and don’t mind paying more for a device that will pay for itself in the long run, the Boldr Kelvin is certainly worth looking into, especially if you have small children or pets you don’t want going anywhere near a space heater.