Compared with wooden beds, spring beds have an obvious advantage, that is, they are breathable. Especially in summer, the heat discharged by human body enters the spring bed net through the sponge pores on the spring mattress, which makes people sleep comfortably (air permeability is a technical index of performance mattress). However, at the same time, it also has a disadvantage. A large amount of water in the human body accumulates in the spring bed net for a long time, which leads to the mildew of cotton felt and brown felt in the mattress, the rust of the spring coil and the generation of a large amount of carbon dioxide. A person usually turns over 40-60 times when sleeping every day. Every time he turns over, the spring will contract and bounce 7- 10 times. Every contraction will squeeze the carbon dioxide accumulated in the mattress bed net out of the mattress. At this time, the carbon dioxide content in the air inhaled into his lungs will be 5-7 times higher than normal. The research results of the University of Chicago Medical Center show that the amount of carbon dioxide inhaled by sleeping on a spring mattress every night is equivalent to the amount of carbon dioxide inhaled by traffic police in busy cities from the road every day. Every day, every month and every year will obviously affect people's health. In addition, too soft spring mattress can't give people uniform and sufficient support, which easily leads to the deformation of the spine. However, an excellent spring mattress will feel hard at first because of its spring shape. However, as time goes on, the spring will collapse, which is harmful to health. Waterbeds do not have these disadvantages. In summer, the heat discharged by human body is absorbed by water, which is not only very comfortable, but also cool and smooth. If it is winter, because the water temperature of the waterbed is adjustable, the moisture generated by the human body will be driven out of the bed with the increase of heat. It makes people sleep warm and dry.