Frequently Asked Questions about Air Dryers

When and why is an air dryer required? ›
Which compressed air dryer should I choose? ›
What is the difference between a cooling and adsorption dryer? ›

When and why is an air dryer required?

We recommend a compressed air dryer for almost all compressed air applications. This is because condensation forms in the compression process of compressed air. This condensation (water) has a harmful effect on your compressed air line network, machines and tools. The use of a compressed air dryer is necessary to protect your production.

An abundance of water and condensation in your air flow can cause a lot of damage to your equipment and production. Water in the compressed air system can:

  • cause corrosion and rust in boilers and piping
  • contaminate oil and lubricant in pneumatic tools and cylinders
  • cause congestion and fog in surfaces sprayed with compressed air

A compressed air dryer removes the unwanted condensed water, giving you dry air and prevents the formation of rust and corrosion.

What is the difference between a cooling and adsorption dryer?

Cooling dryers use a cooling gas to cool the compressed air and then remove the water condensate from the air. With this technique we can reach a temperature of at least 3ºC. ALUP dryers are equipped with R134a, R410A or R45A cooling gas. This gas has the lowest possible environmental impact, and no influence on the ozone layer.

 Adsorption dryers use absorbent to remove the humidity from the compressed air. With this method we can reach a dew point of -20ºC, -40ºC or -70ºC.

Which compressed air dryer should I choose?

The choice of a compressed air dryer depends on the functional requirements for compressed air, regulations (such as BRC, BCAS, IFS and Pharmacopoeia to name a few) and the application.

A cooling dryer is the most used dryer for compressed air. By cooling the temperature back to around 3ºC, most of the moisture is removed and the compressed air is suitable for 90% of the applications. ISO 8573-1: 2010 purity class 4 is met by using a cooling dryer.

The use of an adsorption dryer is desirable when the compressed air must have an even lower pressure dew point. Adsorption dryers have a pressure dew point between -20ºC, -40ºC or -70ºC. Adsorption drying is often used in applications for the food, pharmaceutical, medical and chemical sectors.

Our sales engineers are happy to advise you on choosing the right compressed air dryer for your situation.