Many people find their bathrooms fogged up by the steam from hot water and instinctively wipe it away. This is actually quite unhygienic. Why? Because mirrors also harbor bacteria, thanks to the inherently humid environment of a bathroom. The fog makes the mirror damp, and this dampness attracts bacteria. Wiping it away not only contaminates your hands with bacteria but also doesn't inhibit the growth of bacteria on the mirror. Furthermore, wiping away the fog creates a layer of water on the mirror, obstructing vision. So, what are some effective ways to defog the bathroom? One solution is to design louvered windows in the bathroom. First, open the windows for ventilation. In winter, after showering, the bathroom can sometimes be so foggy that it's impossible to walk. For both safety and ceiling safety, it's essential to open the windows for ventilation. Why? As everyone knows, steam comes from the hot water in a shower. Steam is hot, that's undeniable. Following the principle of "hot rises, cold sinks," the rising steam will create a thin layer of mist on the wall tiles. Mirrors fog up because the mirror reflects the steam more clearly. After passing through the walls, the steam eventually reaches the ceiling and condenses, similar to how small water droplets form when the lid is lifted while cooking. If there are light fixtures on the ceiling and the building materials aren't very waterproof, two things can happen: 1. The light bulbs short-circuit. 2. The ceiling gets moldy. The best solution is to open the windows for ventilation. If you don't mind the cold, you can open the window while showering to let the steam out. This is usually over 60% effective, and the remaining steam won't pose a threat in the bathroom, preventing the mirror from becoming too foggy. The second key element is the ventilation system. Nowadays, many devices can incorporate ventilation systems, with at least two common in bathrooms: bathroom heaters and exhaust fans. In many homes, bathroom heaters offer more than just warm lights and fog lights; some multi-functional models also have defogging capabilities. They utilize their built-in ventilation system, creating a strong suction at the ceiling to collect and expel the condensation. Since bathroom heaters are typically installed above the user's head during showering or bathing, this prevents the condensation from spreading and avoids fogging on mirrors. Exhaust fans, on the other hand, are an older, less efficient method. Their ventilation is relatively rigid, and compared to the defogging function of a bathroom heater, they are at least half as effective. However, improved smart ventilation systems for exhaust fans offer a significant defogging capability and also ventilate the bathroom. Even in the dead of winter when windows are frozen shut, the indoor air remains fresh, preventing stale air and the proliferation of bacteria and viruses. Thirdly, purchasing a screen protector: Nowadays, mobile phones and computers have screen protectors, and there are various styles available, such as high-definition and tempered glass. The same applies to glass mirrors. Many screen protectors are specifically designed for glass, with anti-fog screen protectors being a common choice. Anti-fog screen protectors are frequently seen in public bathrooms and hotels. Their thickness is generally less than 0.5mm, about the thickness of a tissue, and they are simply applied to the mirror surface. They prevent fogging by increasing the overall temperature range of the glass surface, reducing heat loss, resulting in a significant improvement. However, the only drawback is that mirrors come in all shapes and sizes, making custom-made screen protectors impractical. Nowadays, anti-fog screen protectors are often sold as an add-on to bathroom vanities. These three methods are the most effective ways to prevent fogging of bathroom mirrors. Many home remedies found online, such as washing with soap and water, are too troublesome. You can't prepare a basin of soap and water every time you shower, right? Therefore, addressing the root cause is the best long-term solution.