Compressed air dryers

Refrigeration Dryers

Refrigeration dryers are the most commonly used dryers for removing moisture from compressed air. They therefore play an important role in shielding compressed air systems from corrosion and protecting your equipment and end products alike.

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A complete product range

Learn more about our different refrigeration dryers here below.

How does a refrigerated air dryer work?

Here is how they work: Refrigeration dryers come in air-cooled or water-cooled models. Both are used to cool the warm and wet air that comes from the compressor. Initially, that happens in the air-to-air heat exchanger, and then, in a subsequent stage, in the air-to-refrigerant heat exchanger. As the temperature falls, the moisture in the air condenses and can then be drained from the compressed air.
 

That air is then reheated to about room temperature in the air-to-air heat exchanger. That lowers the pressure point of the outgoing flow and prevents the formation of condensation on the outside of the piping system. This heat exchange between ingoing and outgoing compressed air therefore also reduces the required cooling capacity of the refrigerant circuit by lowering the temperature of the incoming compressed air.
 

As the most popular drying technology for compressed air, the applications for refrigeration dryers are nearly endless. 

Refrigeration dryers

Types of refrigerated air dryers: cycling vs. non-cycling air dryer

Non-cycling refrigerated air dryers
Non-cycling refrigerated air dryers are engineered to provide a consistent and steady cooling temperature. This continuous operation mode makes them highly reliable and efficient, especially in industrial settings where the demand for compressed air remains relatively constant. These dryers work by continuously running the refrigeration compressor, maintaining a stable dew point and ensuring that the air remains dry throughout the process.

The primary advantage of non-cycling air dryers is their simplicity and robustness, making them a go-to choice for many applications. Non-cycling dryers are particularly well-suited for environments where the air demand does not fluctuate significantly, thus providing a cost-effective solution for continuous air drying needs.

Cycling refrigerated air dryers
Cycling refrigerated dryers, on the other hand, are designed to adapt to varying demands for compressed air. These dryers can modulate their cooling capacity, adjusting the operation of the refrigeration compressor based on the actual air demand. When the demand for dried air is lower, the dryer reduces its cooling capacity, thereby conserving energy and reducing operational costs.

This ability to cycle on and off in response to demand not only enhances energy efficiency but also contributes to the longevity of the dryer's system components. This type of air dryer is ideal for applications where air usage is not consistent, such as in facilities with varying shifts or production schedules. By aligning their operation with the actual air demand, cycling dryers offer an energy-efficient solution, reducing the overall environmental footprint of the air treatment process.

Both non-cycling and cycling refrigerated air dryers have their unique advantages and are selected based on the specific requirements of the application. Understanding the air demand patterns of your operation is key to choosing the most suitable type of refrigerated air dryer, ensuring optimal performance, energy efficiency, and cost-effectiveness.

Pressure dew point achieved by refrigation dryers

The pressure dew point (PDP) is crucial in the context of refrigerated air dryers. It refers to the temperature at which air, at a given pressure, begins to condense water out of the compressed air. 
 

In refrigerated air dryers, the compressed air is cooled to lower its temperature to the pressure dew point or below, ensuring that moisture condenses into liquid form and can be effectively removed. This process is vital for preventing moisture-related issues in air systems, such as corrosion or freezing in pneumatic controls and pipelines. 
 

Refrigerant dryers typically maintain a PDP of +3 °C/37.4 °F, suitable for most applications

Enhancing efficiency with VSD technology in refrigerated air dryers

The integration of Variable Speed Drive (VSD) technology into refrigerated air dryers marks a major step forward in efficiency and sustainability. By automatically adjusting motor speed to match air demand, VSD dryers use only the energy needed—cutting electricity costs and reducing environmental impact. During low demand, the system slows down to save energy; during peak times, it ramps up to ensure reliable performance.

 

This adaptive operation not only lowers energy use but also extends the dryer’s lifespan by reducing wear on internal components, which means less maintenance and long-term cost savings. Pneumatech’s AC VSD dryers reflect a shift towards smarter, more sustainable air treatment—where efficiency and environmental responsibility go hand in hand.

VSD versus fixed speed graph

Refrigerated air dryer maintenance

Regular maintenance is key to ensuring the longevity and efficiency of refrigerated air dryers. This involves periodic checks and cleaning of the air filters to prevent clogging and ensure smooth airflow.  The condenser coils should be kept clean and free of debris, as accumulated dirt can impede heat transfer and reduce efficiency. It's also crucial to inspect the refrigerant levels and check for any leaks, as insufficient refrigerant can affect the dryer's performance.

 

Drains, which remove the condensed moisture, should be checked regularly to ensure they are functioning correctly and not blocked. Additionally, it's advisable to periodically inspect electrical connections and controls for signs of wear or damage. Implementing a routine maintenance schedule can help identify potential issues early, reducing downtime and extending the life of the dryer. Regular maintenance not only preserves the dryer's condition but also ensures consistent delivery of high-quality, dry compressed air for industrial applications.

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Have questions or want to learn how our compressed air dryers can enhance your operations? Get in touch with us! Our team is ready to share insights and support you in optimizing your processes with our advanced drying solutions. Let’s elevate your operations together!

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