How does a refrigerant dryer work?

What are refrigerant air dryers and how do they work?

The ambient air around us naturally contains moisture and when it is drawn into an air compressor, the moisture is compressed along with the air. This compressed moisture can then negatively affect applications that require quality compressed air that is moisture-free. Additionally, prolonged moisture levels can contribute to other issues within a compressed air system such as corrosion, premature machine failure and product damage. Compressed air refrigerant dryers are, therefore, an ideal solution for removing unwanted and potentially harmful moisture content.

How does a refrigerant air dryer work?

As the name suggests, a refrigerant dryer works by cooling the air down, similar in nature to a domestic refrigerator. Using air to refrigerant exchangers, the compressed air is cooled down to a pressure dewpoint of around +3°C (the temperature at which no more moisture within the compressed air will condense) which causes the moisture content to condense and turn to water. This moisture is then drained off leaving compressed air that is moisture-free. After this cooling and condensing phase, the compressed air is then reheated via a second exchanger as it leaves the dryer. This part of the process is necessary to prevent condensation reforming on the outside of the system.

There are two design variants of refrigerant dryers: non-cycling and cycling (also sometimes referred to as Direct Expansion and Thermal Mass dryers respectively):

Non-Cycling (Direct Expansion) Refrigerant Dryers

Normally a more cost-effective refrigerant dryer to purchase, this type of dryer runs continuously, maintains a stable pressure dewpoint and tends to be popular for small to medium size compressor installations. However, as the refrigerant dryer runs continuously, these model variants generally incur higher operating and maintenance costs than cycling (thermal mass) dryers of similar capacity.

Cycling (Thermal Mass) Refrigerant Dryers

Generally higher in purchase cost than non-cycling (direct expansion) dryers, this type of dryer tends to be popular and provides a good return on investment for medium and larger compressor installations. The dryer concept utilises what is known as a cold energy accumulator with a thermal mass media to effectively store cold energy. These models work by operating only when required to maintain the temperature of the cold energy accumulator in order to maintain the pressure dewpoint of the dryer. This type of dryer is more energy-efficient, reducing operating costs over the longer term and may be eligible for enhanced capital allowances.

What are the benefits of having a refrigerant dryer with your compressed air system?

Air treatment technology offers a complete solution for combating the enemies of your compressed air application. A refrigerant dryer, in particular, will see many benefits for your business and compressed air productivity. All HPC KAESER refrigerant dryers are designed for high-quality industrial applications, providing reliable protection against condensate damage, even under the harshest conditions. Among the many benefits, which you can discuss with a member of our expert team, the key benefits to mention include:

Reliable system protection - HPC KAESER refrigerant dryers offer a complete and reliable, cost-effective solution to combat corrosion in your compressed air system. HPC also offers intelligent energy-saving controls to ensure optimal delivery.
Easy to install - HPC KAESER refrigerant dryers are simple to install with minimal disruption to supply/production.
Minimal maintenance - HPC KAESER refrigerant dryers require minimal maintenance and hence can deliver a maximum amount of uptime.

Things to consider before you install a refrigerant dryer

If you are considering investing in a refrigerant air dryer there are a few key points to keep in mind. Making sure you know and understand the answers to these questions beforehand will help avoid investment in the wrong model or type of refrigerant dryer, which could lead to bigger issues.

The maximum pressure of your refrigerant dryer must be the same or higher than that of your air compressor.
The maximum airflow that can flow through your dryer must be higher than the level your air compressor can deliver. If you refrigerant dryer is too small, it can result in a big pressure drop, higher energy bills and your dryer might not be able to reach the desired dew point.
Know the maximum outside room temperature. If you put your dryer in a hot room, it is likely that the refrigerant dryer will overheat and shut itself down.

Get in touch with HPC to discuss your options for selecting or installing a refrigerant dryer

If you have any questions or would like to discuss your refrigerant dryer options with a member of HPC’s expert team do not hesitate to contact HPC today. We have years of experience in fitting and maintaining refrigerant dryers for a range of business needs, therefore, we are confident we can help you find the right solutions for your individual requirements.

Further information you might find useful

Read further information on HPC KAESER refrigerant dryers in our current product brochures: