Central Air Conditioning Can Dehumidify, Then Why Choose Dehumidifier?
Publish Time: 2020-08-19 Origin: Site
Spring and summer has always been a stuffy and wet season in the south. Especially in the rainy weather, the whole house feels moldy. In the north, the problem of house type is also easy to cause some rooms to be wet. So how to dehumidify the room properly?
1. Difference of Dehumidification Principle between Central AC and Dehumidifier
(1) Dehumidification Principle of Central Air Conditioning
Central air conditioning has dehumidification function in refrigeration mode and independent dehumidification mode.
① Refrigeration Dehumidification Mode
In the process of refrigeration of central air conditioning, the temperature of moist air will drop significantly after passing through the evaporator of air conditioner. The air humidity is in a kind of supersaturated state, and the excess water vapor will be separated out in the form of condensation water and condensed on the fins of evaporator, that is to say, 'condensation'. When the cooling mode reaches a certain balance state, the air humidity will also drop to a certain level. The dehumidification working principle under the refrigeration mode of central air conditioning is actually the‘side effect’accompanying the refrigeration process, which reduces the temperature and humidity at the same time.
② Independent Dehumidification Mode
The cooled air through the evaporator is reheated to the original temperature and then sent into the room. The indoor fan runs at a low speed. The compressor starts and stops, and the refrigeration system makes an intermittent refrigeration cycle. Most of the refrigerating capacity generated is to balance the latent heat of indoor air. That is, water vapor becomes condensate water. A small part is used to balance sensible heat, i.e. reducing some indoor temperature. Such continuous circulation keeps the room temperature close to the set value. At the same time, a large amount of moisture in the air is removed, which is also known as constant temperature dehumidification.
The working principle of the pipeline type central dehumidifier is simply to adopt the air supply and return pipes through reasonable design and construction to carry out centralized dehumidification in all areas of the room. The installation and controller selection have greater flexibility. It can be applied together with the central air conditioning system, or in the attic, long and narrow areas, basement and other special places alone.
(2) Dehumidification Principle of Dehumidifier
The dehumidification principle of refrigerant dehumidifiers that the fan sucks the moist air into the dehumidifier, and the refrigeration system of the compressor lowers the surface of the evaporator below the dew point temperature of the air. At this time, when the humid air passes through the evaporator, the water in the air will decompose and attach to the surface of the evaporator. The water will flow along the hydrophilic platinum on the evaporator to the seeper tray and then to the water tank or drain pipe for discharge. The dehumidified dry cold air will be heated by the water condenser and then discharged out of the machine. Such circulation will reduce the indoor humidity.
2. Choose Dehumidifier is a Better Choice
This is a mistake. The central air conditioning is designed for comfortable temperature. Its main function is refrigeration and heating. Dehumidification is only an auxiliary function. When the air conditioner is dehumidified, the compressor is on for 10 minutes and off for 3 minutes. Through this time limit, humidity can not be really controlled, and air conditioning dehumidification is dehumidification at low wind speed, so dehumidification capacity is limited.
The compact commercial dehumidifier is specially designed to control the environmental humidity. Through the humidity sensor, it can control the start and stop of the compressor well, so that the compressor can operate under high efficiency, so as to accurately control the environmental humidity.
The air conditioner with independent dehumidification function can dehumidify, but the dehumidification capacity is small and slow. Moreover, in the rainy season in the south, the temperature is relatively low, and most of the time is below 20 ℃. At this time, the dehumidification of the air conditioner blows out cold air. The more dehumidification is, the colder and the more uncomfortable it will be. At this time, the long-term dehumidification operation of central air conditioning will also increase the load of the compressor, which not only consumes a lot of electricity, but also easily damages the compressor and shortens the service life of the whole machine.
In a word, according to the above analysis, central air conditioning is not suitable to replace dehumidifier.