Refrigerated compressed air dryers are one of the most common used types of air dryers (for other types, check out our . They are simple in design, need very little maintenance and are relatively cheap. A refrigerated compressed air dryer is the standard choice if you’re shopping for a dryer and don’t have special requirements, like an ultra-low dew point. They don’t need much or any special maintenance and if you buy a quality one, and install it properly, it’s basically set-and-forget.
Dew point is defined as the temperature to which a gas (e.g. air) must be cooled, at constant pressure, for water vapor to begin to condense to liquid water. In other words, when the dew point temperature has been reached, the gas is fully saturated with water vapor.
As the name implies, a refrigerated air dryer works by cooling down the air (like a refrigerator). The warm wet air enters the dryer, where it is cooled down to about 3 degrees Celsius. All water vapor that was in the air condenses into water. Much like your window does on a cold day. The liquid water is then removed from the compressed air by a water-trap.
After that, the cold air is re-heated to room temperature. Since a lot of water has condensed into water, the air is now much dryer.
- Low, initial capital cost.
- Relatively low operating cost.
- Low maintenance costs.
- Not damaged by oil in the air stream (although, filtration normally is sometimes recommended).