Water vapour in compressed air causes corrosion, damages tools and spoils products. An air dryer fixes that, but the right type depends on one number: the pressure dew point (PDP) you need.
Refrigeration dryers
These cool the air so moisture condenses and drains away. They typically deliver a dew point of about +3°C to +10°C. They are economical, simple to run and cost little to maintain. They suit general plant air, workshops, pneumatic tools and most manufacturing. Their limit is that they cannot go below freezing, because the condensate would turn to ice inside the dryer.
Desiccant dryers
These pass air through a drying material such as activated alumina or molecular sieve, which adsorbs the moisture. They reach dew points of -20°C, -40°C or even -70°C, which makes them essential when air must be extremely dry. There are several types:
- Heatless: simple and compact, but they use a share of dried air to regenerate the desiccant.
- Heated, blower reactivated and heat of compression: more energy-efficient for larger flows.
How to choose
| If you need… | Choose |
|---|---|
| Dew point around +3°C, general use | Refrigeration dryer |
| Air outdoors or in cold areas, where pipes may freeze | Desiccant dryer |
| Pharma, electronics, paint, instruments or food contact | Desiccant dryer |
| Lowest running cost for ordinary air | Refrigeration dryer |
Many plants use both: a refrigeration dryer for the main line and a desiccant dryer only where very dry air is needed.
Not sure which fits your plant? Tell us your flow, pressure and required dew point, and Summits will recommend the right dryer.
