Stop the Fog: How to pick the right power for your bathroom mirror
Nobody likes stepping out of a hot shower only to find their mirror looks like a cloud. To fix that, we use infrared (IR) heat to keep the glass just warm enough that steam can’t stick to it. But here’s the trick: you have to get the wattage right. Too low? You’re still wiping the glass with a towel. Too high? You’re wasting power and potentially cooking the mirror’s backing. Picking your power It mostly comes down to how much space you’re dealing with. If you’ve got a tiny powder room—something under 4m²—you don’t need a powerhouse. A 150W to 250W lamp usually does the job. These small rooms don’t hold much steam, so a lower setting keeps the glass clear without making it too hot to touch. Now, if you’re in a big master bath (over 8m²), you’re dealing with a lot more humidity. You’ll want something in the 400W to 600W range. You need that extra muscle to fight off the heavy steam from a large shower. A quick word on heat density It’s tempting to just go for the highest wattage possible to get the fog gone instantly. But wait. If you cram too much heat into one tiny spot, the glass expands unevenly. That’s how you get stress fractures—and nobody wants a cracked mirror. The smart way to do it? Spread the heat out. Use a few lower-wattage tubes instead of one giant heat source. It’s safer and works more evenly. Getting it installed Most of these units run on standard 220V-240V power. When you’re setting it up, make sure the reflectors are polished aluminum. This ensures the heat actually hits the glass instead of just soaking into your wall. One last thing: keep an eye on your circuit load. A single lamp isn’t going to trip your breaker, but if you’re installing four or five of these in one area, you might want a dedicated line. It prevents voltage drops and keeps your lamps from burning out early.