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Thermacell Radius mosquito repeller review: shockingly effective! (without the shocks)

Thermacell Radius and liquid repellant cartridge siting on a wood deck.
Thermacell Radius
MSRP $40.00
“The Thermacell Radius is an effective way to fight back mosquitoes in a small package that won't plague you with the smell of fried insects.”
  • It really works!
  • Operates silently
  • No smell, no noise
  • Small enough to be portable
  • Rechargeable
  • Creates an effective circle of protection
  • Worked for humans and dogs
  • Recharging time is very long
  • Battery could last longer
Thermacell Radius and liquid repellant cartridge siting on a wood deck.

Depending on where you live, you’ve either had a beautiful reprieve from mosquito bites, or you’re being eaten alive. But one thing is true about these bloodsucking bugs: they always show up in force in the end.

I’ve been doing research into mosquito-repelling devices, and the $40 Thermacell Radius Mosquito Repeller has come up a few times as one of the most popular picks. I recently picked up a Thermacell Radius and, in this review, I’ll take a look at what it does, how it works, and — most importantly — whether it works.

What is the Thermacell Radius?

The Thermacell Radius is a small, portable, egg-shaped device that promises to create a zone of protection from mosquitoes. The device itself is a rechargeable pod that weighs less than 7 ounces, and it uses a small liquid repellent refill that should provide hours of coverage.

How does it work?

The name says a lot in this case. “Therma” refers to the heat generated to vaporize a liquid solution in that swappable cartridge, “cell” pertains to how it gets its power from a rechargeable lithium-ion battery cell, and “Radius” is a nod to Thermacell’s claims of providing up to a 15-foot circle of mosquito-free protection.

The core function of the Thermacell Radius is to fire up a low power heating element to spread the chemical in the repellant.


A Thermacell Radius emitting barely noticeable repellant into the air.

Setting up the Thermacell Radius was easy as could be: just remove the protective cap on the refill cartridge, open the magnetic cover of the Radius, drop the refill cartridge in, and close the lid.

Hit the power button to start. Thermacell says it will take about 15 minutes for the repellent to waft into the air and start repelling those pests. (Pressing the button twice will trigger auto shutoff after two hours.)

Keep the device in one spot at the center of the action let it work its magic. The company says it’s effective to about 20 feet from the device.

Using Thermacell Radius

I took the Thermacell Radius camping — be sure to check out our helpful camping hacks — and also tested it out at home, and it was about 15 minutes after powering it on that I started to notice we were all waving our arms around less and no longer slapping at ourselves.

Wary of a potential placebo effect, I asked others in our group if they noticed any difference, and in the end, we all agreed that it provided a noticeable reduction in mosquitoes.

Out in my backyard, the Radius also performed well. On one particularly buggy day, we were able to sit outside for hours and enjoy the warm evening without being ravaged by mosquitoes. I even noticed fewer bugs landing on our dogs, who generally present a bit of a bug buffet due to their thinner coats.

Does it smell or make noise?

One of the selling features (or maybe two?) is that the Radius doesn’t give off any kind of smell. The liquid inside the refill cartridge uses metofluthrin as the active ingredient, which is a DEET-free, odorless chemical specifically created to battle mosquitos. It’s safe for humans and pets, but highly effective in repelling the bloodsuckers.

There are no fans inside the device and I did not hear any noise throughout my testing.

It was a nice experience having no wafting smoke, no stink, no buzzing fan noise, and no buzzing ZAP! of an electrical element frying mosquitos.

Recharging the Thermacell radius in a kitchen.

Battery life and charging

Thermacell says the battery should last about six-and-a-half hours on a full charge and I found that was accurate. Charging a fully drained Radius took an astonishing five hours, but you can leave it on while charging if you don’t mind a slower charging speed. That’s probably the device’s biggest downside — that it takes almost as long to charge it as it does to wear it out.

Our take

I am happy to report that the Thermacell Radius is an effective mosquito repellent that performs way above any of those so-called ultrasonic mosquito repellents. Yes, you need to have a steady supply of refill cartridges to get through the summer, but you won’t waste anything as long as you use it outdoors and place it in a spot away from direct sunlight.

Is there a better alternative?

To be honest, there are plenty of chemicals, zappers, bombs, oils, and repellents out there that all claim to have a lock on mosquitoes. User experience certainly varies. At the moment, I am not aware of a similar or better alternative, but if anyone out there has a recommendation for something else I should try and compare, I’d love to hear it.

Thermacell does offer mosquito repellers like the E55, which boasts a greater coverage area, and there’s also a more rugged moisture-proof cousin dubbed EX55, but the Radius offers a great balance of price, portability, eco-friendliness, battery life, and range.

Should I buy it?

I can absolutely confirm this device works as advertised. If you are experiencing a surge in mosquitoes this season, I can definitely recommend the Thermacell Radius.

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