Thermacell Radius mosquito repeller: does it actually work?


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Erin L

Erin L

thermacell radius, review, how, does it work
Summer here in Calgary feels a bit different this year; for starters it was slow to arrive (we were still wearing toques in June!). But when it got here, a rainy spring contributed to a massive abundance of mosquitos. So how to still enjoy our short summer outdoors without the constant slap and smack of mosquito death? I’ve been investigating mosquito repeller devices. The Thermacell Radius Mosquito Repeller is one of the more popular picks out there and it is high time I give it the full review treatment. You can also check out my top camping gadgets here!

Thermacell Radius mosquito repeller


I am happy to report that the Thermacell Radius is a true mosquito repellent and way above any of those so-called ultrasonic mosquito repellent. Yes, you need to have a steady supply of refill cartridges to get through the summer but thanks to this device’s effectiveness, it’ll be worth it.

Hands-on Testing time: 23 hours over 2 weekends


  • It works!
  • Auto shutoff option
  • Small, portable
  • Easy to use; no app


  • Needs refill cartridges to work
  • Refills are pricey

What is Thermacell Radius?

Thermacell offers several products all focused on providing portable mosquito protection. The Thermacell Radius model in particular, highlights the company’s milestone in making a rechargeable mosquito repellent that weighs less than 200 grams yet capable of providing a half days’ worth of protection out of a single cartridge.
I also need to mention just how cute the Radius is! It comes in two colors – black and sky blue and it looks kind of like an oversized charging case for wireless earbuds. Or a giant egg.

How Does Thermacell Mosquito Repellent Work?

The product name already gives a clue on how the Thermacell mosquito repellent works – “Therma” because it generates heat to vaporize a liquid solution in a swappable cartridge, “cell” because it gets the energy from a rechargeable lithium-ion battery and “Radius” because of Thermacell’s claims of providing up to 15 feet of mosquito-free protection. These concepts do not sound particularly groundbreaking on paper, but the unique design and features of the Thermacell Radius help it stand out.

Set up

I had no trouble setting up the Thermacell Radius. All you have to do is remove the protective cap on the refill cartridge, open the top cover of the Radius, slot the refill cartridge in and close it.

See my video review of Thermacell radius

The Thermacell Radius has a single power button which functions as you would expect it to, but it performs a couple of other duties as well. Pressing the button twice will instruct the Thermacell Radius to switch off automatically off after 120 minutes. Holding the button will lock the device to prevent any accidental triggering. It’s a handy feature to have when traveling since it runs silent.

Takes about 15 minutes to warm up

Because the Radius solely relies on battery power, it takes a bit of time for the unit to heat up and diffuse the fluid inside. Thermacell says up front you need to give it about 15 minutes to power up and create your cone of solitude. So don’t panic if you still see some mosquitoes after leaving it on for a few minutes. Keep the unit in the same spot and let it work its magic.  That was around the time I started to notice we were all waving our arms around less and no longer slapping at ourselves.

Using Thermacell Radius: does it really work?

I used the Thermacell Radius both on a camping trip to a nearby lake, and at home in my backyard. On our camping trip there was a group of six of us, and we all agreed that it provided a noticeable reduction in mosquitoes.
Similarly out in my backyard, it also performed quite well. We were able to sit outside for hours and enjoy the warm evenings without being ravaged by mosquitoes.
Our 12 hour cartridge seems like it’s lasted longer than that, though it didn’t occur to me to time it. A refill cartridge lasting 40 hours is about $19USD.

Does it smell or make noise?

I did not smell anything while testing the Thermacell Radius. The liquid inside the Thermacell Radius refill cartridge has metofluthrin as the active ingredient. Metofluthrin is a DEET-free, odorless neurotoxin that is safe for humans and pets but highly effective in repelling mosquitoes. Here’s a fun fact; some commercially sold mosquito coils contain metofluthrin as well.
The core function of the Thermacell Radius is to fire up the heating element to spread the metofluthrin. 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, so stink and no buzzing ZAP! of  an electrical element.

Battery Life / Charging Time

thermacell radius, review, how, does it workThermacell rates the battery for 6.5 hours and I got around 6 hours from a full charge. Charging a fully drained Radius took about 5 hours but you can leave it on while it is charging if you don’t mind a slower charging speed. If the slow charging is a huge concern for you (it isn’t for me), just hook up a spare powerbank and you should be able to consume an entire cartridge without moving it!

Overall Thoughts on the Thermacell Radius

I am happy to report that the Thermacell Radius is a true mosquito repellent and way above any of those so-called ultrasonic mosquito repellent. Yes, you need to have a steady supply of refill cartridges to get through the summer but thanks to this device’s effectiveness, it’ll be worth it.
thermacell radius, review, how, does it workThermacell does offer higher-end spatial mosquito repellers like the E55 which boasts greater coverage and its rugged moisture-proof cousin the EX55, but the Radius offers a great balance of price, portability, eco-friendliness, battery life and range.
Thermacell Radius sells for about $39USD or (a whopping) $99CAD and you can get it from Amazon.

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Erin L

Erin L

I'm a journalist, tech blogger, writer, TV producer, silversmith& jewelry designer, foodie and world traveler. I blog, write for publications, and supply freelance writing services to Calgary, and the world.

1 Comment

  1. Gail on June 30, 2023 at 6:34 pm

    Really should do some research on your own. Metofluthrin, like other pyrethroids, is neurotoxic in rats, rabbits, and dogs; both sexes were equally sensitive to metofluthrin. Clinical signs include tremor (all species), vomiting (dog only), and increased salivation (rats and dogs). › fs_P…PDF
    US EPA – Pesticides – Fact Sheet for Metofluthrin

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