Drying Principle:
Refrigerated dryers cool compressed air to condense and separate moisture. The air is typically cooled to around 3–7 °C, allowing the condensed water to be removed. Chemical dryers, on the other hand, adsorb water vapor from the air using a hygroscopic (moisture-attracting) material. The most commonly used adsorbents for this purpose are materials such as activated alumina and silica gel. In this system, the dew point can be reduced to as low as -40 °C.

Achieved Dew Point:
Refrigerated dryers generally provide an average dew point of +3 °C. Chemical dryers, however, can achieve dew points down to -40 °C or even lower, making them preferable when drier air is required. Activated alumina delivers high performance especially in applications requiring very low dew points, while silica gel is preferred in certain processes for its fast moisture absorption capabilities.

Energy Consumption and Operating Cost:
Refrigerated dryers typically consume less energy and have lower operating costs. Chemical dryers, on the other hand, may require more energy due to the regeneration process. In heated or heatless models, there is also purge air loss. The regeneration process varies depending on the type of adsorbent used; for instance, activated alumina requires higher regeneration temperatures, whereas silica gel can be regenerated at lower temperatures.

Application Areas:
Refrigerated dryers are commonly used in general-purpose industrial applications (such as CNC machines, paint lines, and packaging lines). Chemical dryers are preferred in sensitive processes that require extremely dry air, such as in pharmaceutical, electronics, food, and petrochemical industries. In these applications, either activated alumina or silica gel is selected depending on the humidity sensitivity of the environment.

Installation and Size:
Refrigerated dryers are generally compact and easier to maintain. Chemical dryers can be more complex and occupy more space due to their regeneration systems. Additionally, the adsorbent material used must be replaced or renewed at specified intervals.

Sensitivity to Ambient Conditions:
The performance of refrigerated dryers can vary depending on ambient temperature and inlet air humidity. Chemical dryers can operate across a wider temperature range, but proper regeneration must be ensured. Activated alumina, in particular, maintains stable performance even under challenging environmental conditions due to its high temperature resistance.