Why Your Bathroom Mirror Fogs Up (And How We Fix It)
Ever stepped out of a hot shower and tried to shave or put on makeup, only to find your mirror looks like a steamed-up windshield? It’s a basic physics annoyance: warm, wet air hits cold glass, and boom—you’re blind. To stop that, we use shortwave infrared (IR) heaters. Here is the trick: we aren’t trying to warm up the whole room. That would take forever. Instead, IR sends energy straight into the glass itself. Getting the heat right We aim to get the glass warm enough to hit the “dew point” in a matter of seconds. Because shortwave IR operates at such a high frequency, it punches through the glass quickly, creating a thermal shield. But you can’t just throw any heater in there. If the wattage is too low, you’ll end up with a clear center and foggy edges. It’s frustrating. We spend a lot of time balancing the power against the size of the mirror so the heat spreads evenly. No cold spots. The guts of the machine For the heating elements, we go with quartz glass. Why? Because these things turn on and off every single time someone walks into the bathroom. That constant “thermal shock” would crack regular glass. Inside, there’s a tungsten filament. We usually fill the lamp with halogen gas. It sounds technical, but all it really does is push evaporated tungsten back onto the filament, which means the bulb lasts much longer. And we don’t mess around with the wiring. We use high-temp rated cables. If you use cheap stuff, the insulation will literally melt and short out against the frame. Not a great way to start your morning. The tricky parts Shortwave IR is incredibly fast, but it getshot. Like, really hot. If the heater is shoved too close to the plastic frame or the mirror backing, you risk warping the whole thing. You need a bit of breathing room—an air gap—so the heat can dissipate. Plus, bathrooms are basically steam rooms. We add a moisture-resistant seal around the electrical housing so the terminals don’t corrode and die after a few months of humidity.