In modern industrial production, air humidity control has become a critical factor influencing product quality, production efficiency, 

and equipment operational stability. As an efficient and energy-saving humidity regulation device, industrial wet membrane humidifiers 

have gained widespread application across multiple industries—including textiles, electronics, printing, telecommunications data centers, 

pharmaceuticals, and tobacco—thanks to their unique humidification principles and significant technical advantages. This article will 

comprehensively analyze the working principle of wet membrane humidifiers, their core performance indicators, the characteristics 

of different types of wet membrane materials, key considerations for equipment selection, and typical application cases. It will also 

objectively analyze their technical advantages and limitations, helping industrial users select the most suitable humidification solution 

based on their specific production environment characteristics to achieve the dual goals of precise humidity control and energy conservation.

Basic Principle and Operating Mode of Wet Membrane Humidifiers

A wet membrane humidifier (also known as an evaporative humidifier) is an air humidity regulation device based on the principle of 

natural evaporation. Its core working principle involves heat and mass exchange through direct contact between water and air. This 

humidification method is an isenthalpic process, meaning it simultaneously lowers air temperature while humidifying, achieving the 

dual effect of “humidification and cooling.” The operational process of a wet membrane humidifier typically includes the following 

key steps:

Air exchange is the core process of wet membrane humidification. When dry air passes through the moist wet membrane under the 

action of a fan, water molecules on the surface of the water film absorb heat from the air and evaporate, while the air loses heat and 

its temperature decreases. This process not only increases the absolute humidity of the air but also achieves isenthalpic cooling. 

According to actual measurement data, under standard operating conditions, the wet membrane humidification process can reduce 

air temperature by approximately 2°C, effectively alleviating the cooling load on air conditioning systems in high-temperature summer 

environments.

A distinctive feature of wet membrane humidifiers compared to other humidification technologies is their fog-free humidification method. 

Unlike ultrasonic or high-pressure micro-mist humidifiers, wet membrane humidification does not produce visible water mist particles, 

thereby avoiding the “white powder” phenomenon (white powder deposits formed by minerals in the water evaporating with the mist) 

and floor dripping issues. This characteristic makes it particularly suitable for cleanliness-sensitive environments such as electronics and 

pharmaceutical facilities.

Performance Characteristics and Advantages of Wet Membrane Humidifiers

Wet membrane humidifiers demonstrate exceptional performance in industrial environments, making them the preferred solution for 

humidity control across various industries. From humidification efficiency to energy consumption, from air purification capabilities to 

system stability, wet membrane technology offers a unique combination of advantages that meet the stringent demands of diverse 

industrial applications.

The clean humidification capability of wet membrane technology makes it particularly suitable for environments with high air quality 

requirements. During the wet membrane humidification process, dust and particles in the air are captured and expelled with the water 

flow as they pass through the moist wet membrane, effectively washing and filtering the air. Unlike ultrasonic or high-pressure micro-mist 

humidifiers, wet membrane humidification does not produce visible water mist or “white powder” phenomena (white powder formed 

by the precipitation of dissolved solids in water), thereby avoiding mineral deposits on equipment surfaces and products. This feature 

makes wet membrane humidifiers an ideal choice for clean environments such as electronics workshops, pharmaceutical factories, and 

laboratories. 

After adopting a wet membrane humidification system, an electronics manufacturing company reduced workshop humidity fluctuations 

from ±15% RH to ±3% RH, resulting in a 28% decrease in product defect rates, fully demonstrating its humidity control precision and 

cleanliness effectiveness.

In terms of environmental adaptability, wet membrane humidifiers perform exceptionally well. By selecting humidification membranes 

made of different materials and configuring corresponding water treatment systems, humidification systems can adapt to various 

water quality conditions. In the case of Inner Mongolia Telecom, despite the poor local water quality, the humidification system could 

still operate stably by adding a pure water device, with no significant impact on the lifespan of the humidification membrane. 

Modern humidification systems also feature intelligent anti-freeze functionality, automatically draining water in low-temperature 

environments to protect the equipment, thereby expanding its applicability across various climatic conditions.

Limitations and applicable scenarios of wet membrane humidifiers

Although wet membrane humidifiers demonstrate numerous advantages in industrial applications, objectively assessing their technical 

limitations is crucial for proper selection and application. Understanding these limitations helps users make informed decisions based 

on their specific needs, avoiding issues or inefficiency caused by mismatches between the equipment and the application scenario.

Volume and humidification capacity limitations are one of the most significant drawbacks of wet membrane humidifiers. Due to their 

reliance on natural evaporation principles, the humidification capacity of wet membrane humidifiers is directly constrained by the 

surface area of the wet membrane and airflow volume. To achieve higher humidification capacity, larger-sized wet membranes must 

be used, resulting in increased equipment footprint. Actual engineering cases show that a wet membrane humidifier with a humidification 

capacity of 10 kg/h typically has a volume 30%-50% larger than that of an electrode-type or high-pressure micro-mist humidifier with the 

same humidification capacity. This characteristic poses challenges for wet membrane humidifiers in installation environments with limited 

space. For example, in existing communication rooms with dense equipment, careful planning is often required to install a wet membrane 

humidifier, and sometimes even adjustments to the room layout are necessary.

In terms of humidity control precision, while wet membrane humidifiers can meet the requirements of most industrial applications, they 

still lag behind high-precision electrode-type humidifiers. The control accuracy of standard humidifiers is typically around ±5%RH, while 

high-end electrode-type humidifiers can achieve ±1%RH. This difference limits the application of humidifier technology in certain 

ultra-precise environments, such as semiconductor manufacturing or high-end laboratories. However, in recent years, through 

improvements in control algorithms and sensor technology, some new humidifiers have achieved control accuracy of ±3%RH, 

narrowing this gap.

Considering the above factors, wet membrane humidifiers are most suitable for the following scenarios: medium to large spaces 

sensitive to energy consumption; environments requiring clean humidification without white powder; locations where humidity 

fluctuations are relatively lenient (±5%RH); and operating conditions where the ambient temperature is typically above 15°C. 

In practical applications, by selecting appropriate models, increasing the number of units as needed, and integrating water 

treatment systems, it is possible to effectively overcome some of the limitations of wet membrane humidifiers and fully leverage 

their energy-saving and environmentally friendly technical advantages.