What is the working principle of an evaporative air conditioner?

An evaporative air cooler is an energy-efficient and environmentally friendly air cooling device. Its core principle is based on the evaporative cooling phenomenon in nature. Compared with traditional compressor refrigeration air conditioners, evaporative air conditioners do not use refrigerants, but absorb heat through water evaporation to achieve the reduction of air temperature. This article will introduce the working principle of evaporative air conditioners and their cooling process in detail.

1. Working principle of evaporative air conditioners
Evaporative air conditioners mainly rely on the physical property of water evaporation to absorb heat to reduce air temperature. When air flows through a moist cooling pad, the water in the pad begins to evaporate. During the evaporation process, water molecules change from liquid to gas, and a large amount of heat needs to be absorbed. This process is called latent heat of evaporation. As the heat in the air is absorbed, the temperature of the air passing through the cooling pad drops, thereby achieving a cooling effect.

2. The main structure and function of evaporative air conditioners
Cooling pads
Cooling pads are the core components of evaporative air conditioners. They are usually made of porous fiber materials or special plastics that can absorb and retain a large amount of water. When the fan pushes the air through the cooling pad, the water evaporates and absorbs heat, causing the air temperature to drop.

Water circulation system
The evaporative air conditioner is equipped with a water pump and a water storage tank. The water pump transports the water in the water storage tank to the top of the cooling pad, and evenly wets the cooling pad through gravity to ensure continuous evaporation.

Fan and filter
The fan draws in outdoor air, cools it down through the wet cooling pad, and then blows it into the room. Some equipment is also equipped with a filter to filter dust and impurities to ensure that the air blown in is clean.

Water level monitoring system
Evaporative air conditioners usually have a water level indicator or alarm function to prompt users to add water in time to avoid affecting the cooling effect due to lack of water.

3. Evaporative cooling process
The cooling process of the evaporative air conditioner can be divided into the following steps:

Air intake
The outside air is sucked into the air conditioner under the action of the fan, and impurities are removed through the filter.

Water evaporation absorbs heat
When the air passes through the wet cooling pad, the water in the cooling pad evaporates, absorbs heat from the air, and lowers the temperature of the air.

Cold air output
The cooled air is transported to the room through the air outlet, which reduces the indoor temperature and increases the air humidity, bringing a cool and comfortable environment.

4. Factors affecting the cooling effect of evaporative air conditioners
Environmental humidity
The effect of evaporative cooling is closely related to the ambient humidity. In a dry environment (relative humidity below 50%), the evaporation rate is fast and the cooling effect is significant. In areas with high humidity, the moisture in the air is close to saturation, the evaporation rate is reduced, and the cooling effect is not as obvious as in a dry environment.

Air flow rate
The wind speed of the fan determines the speed at which the air passes through the cooling pad. A moderate wind speed can increase the water evaporation efficiency, thereby improving the cooling effect.

Cooling pad material
High-quality cooling pads have strong water absorption and large evaporation area, which can provide more efficient cooling effect.

Water temperature and water quality
Lower water temperature helps to improve the cooling effect, while good water quality can avoid clogging or corrosion of the cooling pad and extend the life of the equipment.

5. Advantages of evaporative air conditioners
Energy saving and environmental protection
Evaporative air conditioners only use water and wind energy for cooling, with low energy consumption and no use of refrigerants such as Freon, which is more environmentally friendly.

Wide range of application
Evaporative air conditioners are suitable for dry homes, offices, factories or outdoor places, especially in low humidity areas, where the effect is particularly significant.

Increase air humidity
In addition to cooling, evaporative air conditioners can also increase air humidity, which helps improve the comfort of dry environments.