Every midsummer, under the mandatory care of the sun, how much I wish I could have an igloo to cool off in, but this summer summer artifact is built in the coldest area on earth? , build their Inuit only for heating with ice in an environment of dozens of degrees below zero? And it's quite happy, why can their igloo keep the heat without melting, what magical secrets will there be in the little igloo?
In the northern part of the earth, in the Canadian Arctic Circle, there live the most frost-resistant and Inuit people on earth. Their images are easy to associate with, they wear rare animal skins, have a strong body, and there are ice residues in their beards and hair. In a white awn and cold snow, yes, the Inuit people have lived in this wind and snow for all generations, living in a frost-proof house thousands of years ago - an igloo, but now that the material conditions are better, the igloo can be When the electricity is turned on, some people say that the small house where the ice cubes are piled up is full of ice inside and outside. It makes people look cold.
Don't underestimate the small igloo, in the arctic of minus dozens of degrees all the year round, its hard body is the hope of the local Inuit people to survive, and it is very durable, as long as the global climate does not heat up, such The igloo can last forever. The insulation in the igloo has a remarkable effect. The temperature outside the house can reach minus tens of degrees, and the temperature inside the house can reach zero to ten degrees. Say, this is the most suitable temperature, then the problem comes, we all know that melting ice above zero is common sense, how does this small house made of ice cubes keep warm and the ice will not be melted? ?
Before we understand how igloos are kept warm, we must first understand how igloos are built. The construction of igloos is not as simple as it seems, and there is no way out, even in extremely cold and harsh environments.Driven by the desire to survive, the Inuit can also live well. To build an igloo, they must first choose a suitable place for snow accumulation. Snow that is hoarding air, ice cubes lack pores, and heat insulation is not as good as snow, so you need to be careful when choosing. Experienced people will poke it with a knife to judge whether it is suitable for building a house. After selecting ice cubes, use a knife to make it Rectangle, then use snow bricks to make a circle around the rectangle, take away the cuboid grooves created by the snow bricks, after making a circle around the rectangular grooves, cut a part of the snow bricks into bevels to form a spiraling fortress , so that the bricks above the igloo are not easy to fall off, and then based on the ice brick slope, cut the snow bricks along the "conical spiral", and gradually close the seam and finally leave a ventilation hole. The gaps between the bricks are filled and blocked tightly. Some Inuit people also use animal skins to make door curtains to block the wind. Will the house be warm inside after it is built?
How do Inuit people live here ?
There are three main types of heat transfer, heat conduction heat convection and heat radiation , in order to reduce heat conduction in the igloo, Inuit people will wear thicker clothes, there is definitely no problem in wearing more clothes. The place where the special people sleep is relatively high. In fact, the hot air is lighter and will go up. The cold air is heavier and will sink. This situation is more obvious in the igloo. The cold air gathers at the bottom of the igloo . Especially at the door, and the air heated by the human body and the oil lamp will float upward, so in order to ensure that the sleeping place is not frozen, the place where they live and sleep should be close to the top of the snow house.
Also, when the indoor temperature is below 15 degrees, the human body radiates photons in the ice wall back and forth reflects , and a small part of the photons are absorbed by the wall,However, the energy is not enough to melt the ice surface. The temperature of the outer wall is tens of degrees below zero. Although the large temperature difference can transmit the heat of the photons, the water vapor exhaled by the indoor human body will be sublimated when it touches the wall. The transformation process will release a large amount of thermal infrared photons, offsetting the heat dissipated by the ice wall, so if you want to keep the house warm, the premise is that there is either someone in the room or a basin of water, and furniture or people must keep a certain distance from the wall. When the ice wall condenses the surrounding water vapor, no or only a small amount of latent heat of condensation will be conducted outside the house, and most of it will be returned in the form of photons. The place survived at ten degrees. In addition, the white snow can reflect part of the thermal radiation of the human body and can also play a role in thermal insulation. Therefore, even if the outside temperature reaches minus fifty degrees, the inside of the house can still be maintained at about zero degrees. The problem of thermal insulation Solved,
Then why does it not melt? There are many pieces of speed, and the freezing speed can always catch up. In addition to natural conditions, the Inuit will also hang animal skins inside the igloo for heat insulation, in this way to prevent the house from being too high and melting the house. Now, the igloo seems simple, and it was developed by people in extremely hard and arduous environment. They don't understand science, but the instinct for survival forces them to find out such a unique thermal insulation method after long-term practice, so human beings The survival instinct is very powerful, don't you think?
Also, when the indoor temperature is below 15 degrees, the human body radiates photons in the ice wall back and forth reflects , and a small part of the photons are absorbed by the wall, but the energy is not enough to melt the ice surface, the outer wall The temperature is tens of degrees below zero. Although the large temperature difference can transmit the heat of photons, the water vapor exhaled by the indoor human body will sublime when it touches the wall. This phase change process will release a large number of thermal infrared photons, which offset the The heat dissipated by the ice wall, so if you want to keep the house warm, the premise is that there is either someone in the room or a basin of water, and the furniture or people must keep a certain distance from the wall. When the ice wall condenses the surrounding water vapor, No or only a small amount of latent heat of condensation will be conducted outside the house, and most of them will be fed back in the form of photons. In short, the temperature given by the self-heating of the human body is enough to survive at a temperature of minus tens of degrees. Snow can reflect a part of the human body's thermal radiation, and can also play a role in thermal insulation, so even if the outside temperature reaches minus 50 degrees, the inside of the house can still be maintained at about zero degrees. The thermal insulation problem is solved. Why doesn't it melt?
Snow must melt above zero degrees, but it is not blowing at dozens of degrees below zero outside. If freezes faster than the melting speed, it will go up. No matter how fast you melt, the freezing speed will always catch up. Well, in addition to natural conditions, the Inuit will also hang animal skins inside the igloo for heat insulation, in this way to prevent the house from being melted due to the high temperature inside the igloo. Under extremely hard and arduous environment, they did not understand science, but the instinct for survival forced them to go through long-term practice to find out such a unique thermal insulation method, so the instinct of human survival is very powerful, do you think Woolen cloth?
