ABAC DRY refrigeration dryers for compressed air

Dew point +4 °C

ABAC DRY refrigeration dryers dry compressed air to a pressure dew point of +4 °C. The air is cooled in a heat exchanger, the water vapour condenses and a level-controlled electronic drain discharges only the water, without losing any compressed air.

The range has 17 sizes from 16 to 1,080 m³/h (266 to 18,000 l/min at 7 bar). The small dryers DRY-20 to DRY-130 work up to 16 bar, the larger ones up to 14 bar. The manufacturer built them on reliable components, a low R513A refrigerant charge and a controller that displays the dew point.

What the ABAC DRY dryer can do

• Level-controlled electronic condensate drain
• Controller displays the dew point and reports alarms
• Constant dew point under any load
• Low pressure drop across the heat exchangers
• Low R513A refrigerant charge
• Compact, light cabinet with easy access to components

Sizes and technical data

The code leads to the dryer card. The flow rate applies to the manufacturer’s reference conditions.

The flow rate is stated according to ISO 7183 for a pressure of 7 bar, inlet air at +35 °C, a room temperature of +25 °C and a pressure dew point of +4 °C ± 1 °C. The power input applies to R513A refrigerant and a 50 Hz supply; the manufacturer supplies other voltages and frequencies on request.

How to choose the size

The dryer must handle the full output of the compressor. The flow rate in the table applies to the reference conditions; the actual flow rate changes with the room temperature, the inlet air temperature and the pressure. Multiply the nominal flow rate by the manufacturer’s three correction factors:

actual flow rate = nominal flow rate × room temperature factor × inlet temperature factor × pressure factor

Example: the compressor delivers 2,000 l/min at 8 bar, the inlet air is at +40 °C and the room at +30 °C. DRY-165 with a nominal flow rate of 2,350 l/min handles 2,350 × 0.91 × 0.82 × 1.03 = 1,806 l/min, which is not enough. DRY-210 handles 3,000 × 0.91 × 0.82 × 1.03 = 2,306 l/min and is suitable.

Room temperature factor

Inlet air temperature factor

Pressure factor

A room temperature of +46 °C and inlet air at +60 °C apply only to DRY-690 to DRY-1260, a pressure of 15 and 16 bar only to DRY-20 to DRY-130.

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How the ABAC DRY dryer works

Warm humid air from the compressor first passes through the air/air heat exchanger, where it is pre-cooled by the dried air leaving the dryer. In the evaporator the refrigerant cools it to a pressure dew point of +4 °C, the water vapour condenses and the separator with a demister catches the droplets.

On its way out, the cold dry air is reheated in the air/air heat exchanger, so no water condenses on the piping downstream of the dryer. The hot gas bypass valve controls the refrigerant capacity under every load, which keeps the dew point constant.

Parts in the diagram

1. refrigerant compressor
2. condenser
3. motor-driven fan
4. air/air heat exchanger
5. air/refrigerant evaporator
6. condensate separator with demister
7. refrigerant separator
8. maximum pressure switch
9. service valve
10. fan pressure switch
11. hot gas bypass valve
12. refrigerant filter
13. capillary tube
14. service valve
15. dew point thermometer
16. dirt trap
17. automatic condensate drain
18. dew point indicator

Components inside

The refrigerant compressor is driven by an electric motor; it is cooled by the refrigerant itself and protected against thermal overload. The condenser, cooled by room air, has a large heat exchange surface and a fan drives the air through it.

The air/air heat exchanger and the air/refrigerant evaporator have high thermal performance and a low pressure drop. The manufacturer tested the components under extreme operating conditions and arranged them for easy access.

Three cabinet sizes

The range has three cabinet types. The photos always show one size from each group.

Control and alarms

The electronic controller shows the dryer status, the fan status and the pressure dew point. It reports a high or low dew point and reminds you of service; on DRY-85 to DRY-530 it also reports a fan probe failure. The dryer is switched on with a button on the front.

DRY-250 to DRY-530 have a potential-free contact for the dew point alarm, high refrigerant temperature and fan probe failure. DRY-690 to DRY-1260 have a general alarm (dew point, refrigerant temperature, probe failures, high-pressure switch, electrical failure), a drain alarm and remote start/stop.

Level-controlled condensate drain

The whole range has a level-controlled electronic condensate drain. Sensors detect when there is water in the reservoir and open the valve only to discharge it. No compressed air escapes and the dryer saves energy; the drain adjusts itself to the amount of condensate.

Filter support and bypass for DRY-20 to DRY-130

For the small dryers DRY-20 to DRY-130 the manufacturer offers two options. The filter support allows two filters to be mounted directly on the back of the dryer, so the set takes up less space and installation costs less.

The filter support with bypass also lets the air flow through the filters only during maintenance or a fault of the dryer, so operation does not stop. Filters are not included in either option.

Typical installation with filters

The manufacturer places a G filter after the compressor with aftercooler, then the dryer and a C filter after it (installation on the left). The air then reaches particle class 1 and oil class 2 according to ISO 8573-1; with an additional V activated carbon filter (installation on the right) also oil class 1. A vertical air receiver is always recommended.

In our shop you will find matching dust filters, microfilters and activated carbon filters; the purity classes are explained under industrial filters according to ISO 8573-1.

R513A refrigerant

The manufacturer fills ABAC DRY dryers with a small charge of R513A refrigerant, which has a low global warming potential. The circuit is protected by a maximum pressure switch, a refrigerant filter and a refrigerant separator upstream of the compressor.

Dew point and air purity

Compressed air carries water, oil and solid particles. The water content is given by the pressure dew point: the temperature at which the air is saturated with moisture. When the air cools to the dew point or below, the water condenses and causes corrosion, rust and leaks in the piping.

The ABAC DRY dryer reaches a dew point of +4 °C ± 1 °C, i.e. water class 5 according to ISO 8573-1. For a dew point of +3 °C there are RDS refrigeration dryers; for a dew point below 0 °C, for example for piping running outdoors in winter, a desiccant dryer is needed.

Technical data of the ABAC DRY range

How do I choose the size of the dryer?

According to the compressor output. Multiply the nominal flow rate from the table by the correction factors for the room temperature, the inlet air temperature and the pressure, and choose a dryer that handles the full compressor output.

What dew point does the ABAC DRY dryer reach?

A pressure dew point of +4 °C ± 1 °C, i.e. water class 5 according to ISO 8573-1. For a dew point below 0 °C a desiccant dryer is needed.

Does compressed air escape through the drain?

No. The level-controlled electronic drain opens only when there is water in the reservoir and discharges only the water.

Where can the dryer be installed?

In a room at +5 to +43 °C, the large DRY-690 to DRY-1260 up to +46 °C; above +25 °C the flow rate is reduced by a correction factor. The condenser is cooled by room air.

What power supply does the dryer need?

DRY-20 to DRY-530 are connected to 230 V, single phase; DRY-690 to DRY-1260 to 400 V, three phases. The manufacturer supplies other voltages and 60 Hz on request.

Can filters be mounted on the dryer?

On DRY-20 to DRY-130, yes: the optional filter support holds two filters on the back of the dryer, and with the bypass the set can run through the filters even while the dryer is being serviced.

The technical data of ABAC DRY dryers are based on documents from the manufacturer ABAC (leaflet DRY 20-1260, 2026 edition).

You will find other types of dryers among the compressed air dryers.