What the OFD range covers
The OFD series is OPPAIR's refrigerated air dryer family, built to remove condensed water from compressed air before it reaches tools, pipelines or processes. The range spans models OFD-1.5N through OFD-25N, covering 1.5 to 25 m3/min of rated flow.
| Parameter | Range |
|---|---|
| Models | OFD-1.5N to OFD-25N |
| Rated flow | 1.5 to 25 m3/min |
| Working pressure | 2 to 10 bar standard |
| Pressure dew point | 2 to 10 degrees C |
| Max ambient temperature | 45 degrees C |
| Air connection | DN25 to DN80 |
| Power supply | 220 V / 50 Hz / 1 phase or 380 V / 50 Hz / 3 phase |
Why pressure dew point matters
A refrigerated dryer does not dry air to instrument level, and that is not its job. It brings the pressure dew point down to roughly 2 to 10 degrees C, which is below the temperature of most factory pipework and therefore stops condensation forming downstream. For lines running outdoors, in unheated buildings or where the pipework passes through a cold zone, the dew point has to sit below the lowest pipe temperature, or water will reappear inside the line.
Selection points we check first
- Rated flow at your actual inlet conditions, not the nameplate figure - a dryer rated at 25 m3/min at 25 degrees C ambient delivers less when the compressor room runs at 40 degrees C.
- Inlet air temperature: a dryer placed directly after the compressor sees hotter air than one fed from a receiver and a pre-cooler.
- Working pressure: capacity tables are quoted at a reference pressure, and flow capability falls as line pressure falls.
- Site voltage and phase: single-phase 220 V builds suit smaller workshops, while 380 V three-phase is the normal industrial configuration.
Where it sits in the system
The usual order is compressor, air receiver, pre-filter, refrigerated dryer, then the precision filter chain. Putting the receiver ahead of the dryer lets the air cool and drop bulk water before the dryer does the fine work, which reduces the dryer's load and stabilises its cycle.
Available options
Working pressures of 12, 16, 20 and 30 bar are available as custom builds beyond the standard 2 to 10 bar band. Voltage variants, panel colour, logo and configuration can also be specified for OEM and distributor projects.
Tell us your working pressure, required flow and site voltage, and we will match a configuration. Send an enquiry.