How to actually pick the right infrared power for your bathroom mirror
Ever walk out of a steaming hot shower, look at the mirror, and see… absolutely nothing? Just a wall of white fog. It happens because that warm, wet air hits the cold glass and just sticks. The trick is to use shortwave infrared lamps to keep the glass warm—warmer than the “dew point,” for the science folks. But here’s the catch: if you get the wattage wrong, you’re either paying for electricity you don’t need or you’re still staring at a foggy mirror. Matching the power to the room If you’re dealing with a tiny powder room (under 5m²), you don’t need a powerhouse. A small lamp—somewhere between 150W and 300W—usually does the trick. It’s just enough to keep the chill off the glass. But for those big master baths (10m² and up), you’ve got a lot more moisture to fight. You’ll want to bump things up to 500W or 600W. It gives you that extra punch of heat so the mirror stays crystal clear even when the shower is running on full blast. The “too much of a good thing” problem You might think, “Why not just go for the biggest lamp every time?” Well, because you don’t want to crack your mirror. If you shove a 600W lamp behind a thin piece of glass in a small frame, you risk overheating the silver backing or, worse, shattering the glass. It’s all about the balance between the wattage and how much breathing room the lamp has behind the mirror. We use quartz envelopes because they heat up fast. Like, seconds fast. Since they work so quickly, you don’t need to leave them running all day. Just hook them up to a timer or a humidity sensor. Your lamps will last way longer, and your electric bill will thank you. A few real-world tips for installation Before you flip the switch, double-check your circuit. A few high-wattage lamps can pull a lot of juice, and there’s nothing worse than tripping a breaker right when you’re getting ready for work. And please, make sure your housing is rated for damp zones. Water and electricity aren’t friends, and a short circuit is the last thing you want in a bathroom.