It's humid in the south. Can the doors and windows at home be opened for ventilation?

Living in the south, I will experience a special kind of weather every March and April-returning to Nantian. Being in a high humidity environment for a long time will not only affect comfort, but also make furniture and clothes moldy, so dehumidification is necessary. There are many methods of dehumidification, such as dehumidifier, air conditioner and desiccant. What's the difference? Which method is better? To understand this, we must first understand what is humidity?

Simply put, humidity represents the content of water vapor in the air at a certain temperature and volume, which is generally expressed by absolute humidity and relative humidity. Absolute humidity is easy to understand. The mass of water vapor contained in air per cubic meter is in g/m?

However, what we often see is relative humidity. For example, the air humidity in a certain area is 60%, 80% ... indicating the percentage of actual humidity and saturated humidity in the air at the same temperature. The most comfortable humidity of human body is about 50%~60%, which is kept above 70% all the year round in South China and even reaches 90% in summer.

It should be noted that the relative humidity will be affected by the temperature. The higher the temperature, the greater the saturation limit of air humidity, and vice versa. That is to say, at different temperatures, even if the relative humidity is the same, the actual water content is different.

We can compare air to a water bottle. Assuming that the temperature in Beijing is 10℃ and the maximum capacity of the water bottle is 100ml at this temperature, the actual water content in the air is 50ml when the relative humidity is 50%. However, when the temperature in Guangzhou is 20℃, the maximum capacity of the water bottle is increased to 200ml due to the higher temperature, and the actual water content is 100ml when the relative humidity is 50%. Obviously, although the relative humidity is 50%, the air in Guangzhou is wetter than that in Beijing.

This can also explain why when we return to the southern sky, water droplets will start to appear on the walls and floors of our homes. The temperature is not high in March and April. At this time, wet and warm air enters the southern part of China along the ocean, and hot air containing a lot of water meets indoor cold air, just like pouring water from a big bottle into a small bottle and overflowing at once. Therefore, we must not think that opening a window in the south can dehumidify, which will only let more moisture enter the room and condense into water droplets. Instead, try to close the doors and windows.

As mentioned above, the most commonly used dehumidification methods are air conditioning, dehumidifier, desiccant and so on. Desiccant generally refers to dehumidification box, which is suitable for closets, cupboards and other small spaces. Buy a few boxes for a few days and you can see that you have absorbed a lot of water. This method is more economical and convenient.

But for the whole room, dehumidification box is definitely not enough. At this time, we have to rely on air conditioners and dehumidifiers. Their principles are basically the same. The internal compressor is used to cool the radiator. When the air passes through the cooler radiator, some water vapor will condense into water, thus reducing the moisture in the air.

Seeing this, some people will ask, since air conditioners also have dehumidification function, why use dehumidifiers?

First of all, the air conditioner has the best operating humidity when it is designed. According to national standards, the humidity should not exceed 70% under any working conditions. If it is operated in a high humidity environment, it will bring extremely high power consumption. A humid environment like Guangdong may consume 50% more electricity as long as it drops by one degree.

Secondly, the higher the energy efficiency grade, the better the cooling effect, but the dehumidification effect is average. Because of the large air volume and large radiator area, the surface temperature of the radiator will not be particularly low, thus reducing the efficiency of water condensation. Finally, the essence of air conditioning dehumidification is refrigeration. If it is in a relatively wet and cold area, the experience of air conditioning dehumidification is very bad.

Dehumidifier is specially designed for dehumidification, and the compressor has less power, which is more suitable for running in high humidity and saves electricity than air conditioning. At the same time, it is small in size, can be moved at will, and can be placed in a room that needs dehumidification.

Therefore, if the humidity in the area is not very high, it is necessary to dehumidify occasionally, and air conditioning can also be used. If it is a coastal area with high humidity, the effect and experience are better with dehumidifier.