眾所周知恒溫恒濕機它的溫度系統有兩個子系統，分別為加濕和除濕這兩個子系統，而加濕一般采用蒸汽加濕，簡單來講就是將低壓蒸汽直接注入箱內進行加濕。用這種方法加濕它的速度快，加濕控制更加靈敏，尤其是在降溫時能很好地實現強制加濕。

　　而恒溫恒濕機的除濕又有兩種，機械制冷除濕和干燥除濕。所謂的機械制冷的除濕原理是將空氣冷卻到露點溫度以下，使大于飽和含濕量的水汽凝結析出，這樣就降低了濕度。干燥器則是利用氣泵將試驗箱內的空氣抽出，并將干燥的空氣注入，同時將濕空氣送入可循環利用的干燥進行干燥，干燥完后又送入試驗箱內，如此反復循環進行除濕。

　　恒溫恒濕機的加濕系統與加熱系統大致一樣;它是加熱器加熱水變成蒸汽過程;完成加濕目的。降濕系統也是靠制冷系統完成，蒸發器放在設備里面;里面高濕氣體會見冷的物體冷凝成液體;如此反復箱體的高濕氣體會很少，從而達到降濕目的

It is well known that there are two subsystems in the temperature system of constant temperature and humidity machine, namely, humidification and dehumidification subsystems. Steam humidification is generally used for humidification. Simply speaking, low pressure steam is injected directly into the box for humidification. With this method, the humidification speed is faster and the humidification control is more sensitive. Especially when the temperature is lowered, the forced humidification can be well realized.

There are two kinds of dehumidification of constant temperature and humidity machine, mechanical refrigeration dehumidification and drying dehumidification. The so-called dehumidification principle of mechanical refrigeration is to cool air below dew point temperature, so that water vapor with more than saturated moisture content condenses out, thus reducing humidity. The dryer uses an air pump to extract the air from the test box and inject the dry air into it. At the same time, the wet air is sent to the recyclable drying for drying. After drying, it is sent to the test box again and again for dehumidification.

The humidifying system of constant temperature and humidity machine is similar to that of heating system. It is the process of heating water to steam in heater and completes the purpose of humidifying. The dehumidification system is also completed by the refrigeration system, the evaporator is placed in the equipment; the high humidity gas inside meets the cold object to condense into liquid; so the high humidity gas in the repeated box body will be very few, so as to achieve the purpose of dehumidification.