Physics knowledge hidden in doors and windows

We can see all kinds of window glass in the classroom, at home, in the car at any time, don't look at it ordinary, but there are many physical phenomena, contains a lot of physical knowledge.

When the weather is cold, the window glass in the classroom becomes blurred, but the window glass at home does not have this phenomenon?

When the weather is cold, the water vapor in the classroom meets the cold glass and liquefies, and adsorbs on the window glass, so the glass becomes cloudy. There are many people in the classroom, and the water vapor content in the air is much larger than that at home, so this phenomenon is very obvious in the classroom, but not obvious in the home.

A sudden drop in temperature outside, The rooms with closed doors and Windows are still warmer?

Outside, cold air replaces hot air due to the movement of air, so the temperature outside drops suddenly. If the doors and windows are closed tightly, the hot air inside cannot exchange with the cold air outside, and the room is warmer. It is also the same reason to close the doors and windows when you turn on the air conditioner in summer.

Most of the windows in bathrooms and toilets use frosted glass. What is the function of it?

Frosted glass, also known as acid etched glass, is made by mechanically sandblasting, manual grinding or hydrofluoric acid erosion on the surface of flat glass to form a uniform matte surface. Light can be refracted when it hits the glass, but due to the rough surface, its refraction is chaotic, so it has the characteristics of light transmission but not see-through. This kind of glass is mostly used in rooms that need to be concealed or undisturbed, such as doors and windows in bathrooms, toilets and offices.

Why is it sometimes distorted when looking at objects through window glass?

Sometimes the refracted light deviates due to uneven glass (material, thickness, etc.) or uneven surface, and these rays are then shot into the human eye, and the objects seen by people become deformed.

When the wind is up, if the window is not closed tightly, leaving a small gap will hear a whimpering sound. What is this?

This is because the windows are not closed tightly, leaving some small gaps, when the air passes through the small gaps quickly, just like we whistle, causing the air to vibrate and make a sound, and the louder the wind, the louder the sound; the gaps The smaller it is, the higher the pitch of the sound.

Why does the noise outside become less after closing the doors and windows?

There are three ways to attenuate noise: at the source, in the process of propagation, and at the human ear. If the noise source is outside, closing the doors and windows will weaken the noise in the process of propagation, and the noise will become smaller. The better the sealing performance of the doors and windows, the more noise can be attenuated.

During the day, people can see the bustling street scene outside through the heat-reflecting glass curtain wall from indoors, but they cannot see the indoor scenery from the outside, which can play the role of screen shielding. The situation at night is just the opposite. Due to the lighting effect of indoor light, things outside the glass curtain wall cannot be seen indoors, giving people a sense of comfort without external interference. There is also a kind of insulating glass, which has the functions of heat insulation and sound insulation when used as window glass.

If you want to know more, feel free to contact us: kevin@kxglass.com.