
CompAir D Series
Two-stage, oil-free screw compressors – 100 % oil-free compressed air
With the new D37–D75 series, CompAir is extending its portfolio of oil-free screw compressors to the medium power range of 37 to 75 kW. The new models are available with both fixed-speed and variable speed drive technology (RS) and deliver reliable compressed air certified to ISO 8573-1 Class 0 – completely free of oil and silicone.
This series is particularly suitable for applications with the highest air purity requirements, such as those found in the food and beverage industry, pharmaceuticals, textile manufacturing and electronics production.
Motor power
37 kW to 75 kW
Pressure range
8 bar to 10 bar
Flow rate
6.0 m³/min to 12.7 m³/min
Benefits of the D37–D75 series

- Certified air quality: 100 % oil-free air according to ISO 8573-1:2010, Class 0 – no risk of contamination.
- Power range 37–75 kW, flow rate up to 12.7 m³/min at 7 bar(g).
- Available with fixed or variable speed (RS) – for maximum energy efficiency in part-load operation.
- Air- or water-cooled – depending on application and ambient conditions.
- Perfect complement to existing models from 75–315 kW – a continuous portfolio.
- Low operating costs thanks to low pressure losses, low temperatures and highly efficient control.
- Optional heat recovery: process water up to 90 °C can be generated (ERS Ready).
- Can be integrated with HOC dryer (Heat of Compression) for dew points < –40 °C without additional energy.
- Reliable operation thanks to durable components, patented UltraCoat™ coating and stainless steel components.
Construction & design
The two-stage compression of the D Series delivers maximum efficiency and operational reliability combined with lower energy consumption. The main features at a glance:
- Robust compression stages with UltraCoat™ coating: corrosion protection and long service life.
- Second-stage rotors made of stainless steel, precision-made gears, oversized bearings.
- Labyrinth-type oil seals made of stainless steel for maximum tightness.
- Optimised piping made of stainless steel, aluminium and specially treated materials.
- HPM motors (High Performance Motor) on RS models:
- Energy savings of up to 30% compared with conventional controls
- Unlimited start-stop cycles
- Longer service life and reduced maintenance costs
- Low maintenance: 8,000 operating hours between coolant changes, easily accessible main components, no special tools required.

Control

The D Series is equipped with a modern, intuitive controller:
User interface (standard & RS models)
- 5.7” colour display with user-friendly navigation
- Visualisation of more than 30 operating parameters
- Modbus interface & Ethernet connection
- Remote access from tablet, PC or smartphone via web server
- iConn integration for cloud-based monitoring and condition analysis
- Trend charts & event history – ideal for maintenance planning and optimisation
- Direct connection to SmartAirLite or central control units (SAM) via RS485
Technical data
D37 – D75s, fixed speed
| Model | Cooling method | Rated motor power [kW] | Rated pressure [bar g] | Free air delivery at rated pressure [m³/min] | Dimensions L × W × H [mm] | Noise level at 8 bar g [dB(A)] | Weight [kg] | ||
|---|---|---|---|---|---|---|---|---|---|
| 7 bar g | 8.5 bar g | 10 bar g | |||||||
| D37 | Air | 37 | 7 / 8,5 | 6,0 | 5,1 | – | 2248 × 1372 × 1917 | 76 | 2387 |
| Water | 6,0 | 5,2 | 76 | 2410 | |||||
| D45 | Air | 45 | 7 / 8,5 | 7,7 | 6,5 | – | 2248 × 1372 × 1917 | 76 | 2497 |
| Water | 7,7 | 6,5 | 76 | 2520 | |||||
| D55 | Air | 55 | 7 / 8,5 / 10 | 9,6 | 8,8 | 7,7 | 2248 × 1372 × 1917 | 76 | 2577 |
| Water | 9,6 | 8,8 | 7,8 | 76 | 2600 | ||||
| D75s | Air | 75 | 7 / 8,5 / 10 | 12,7 | 11,6 | 10,7 | 2248 × 1372 × 1917 | 76 | 2682 |
| Water | 12,7 | 11,7 | 10,8 | 76 | 2705 | ||||
D37RS – D75RS, variable speed
| Model | Cooling method | Rated motor power [kW] | Rated pressure [bar g] | Free air delivery at rated pressure [m³/min] | Dimensions L × W × H [mm] | Noise level [dB(A)] | Weight [kg] |
|---|---|---|---|---|---|---|---|
| D37RS | Air | 37 | 8,5 | 5,1 | 2080 × 1115 × 2070 | 65 – 74 | 1579 |
| Water | 63 – 69 | 1624 | |||||
| D45RS | Air | 45 | 8,5 | 6,3 | 2080 × 1115 × 2070 | 65 – 74 | 1579 |
| Water | 63 – 69 | 1624 | |||||
| D55RS | Air | 55 | 10 | 7,8 | 2078 × 1321 × 1947 | 76 – 80 | 2042 |
| Water | 76 – 80 | 2042 | |||||
| D75RS | Air | 75 | 10 | 10,6 | 2078 × 1321 × 1947 | 76 – 80 | 2042 |
| Water | 76 – 80 | 2042 |
Frequently asked questions
What applications is the CompAir D Series suitable for?
For applications with the highest demands on air purity, for example in the food and beverage industry, pharmaceuticals, textile manufacturing and electronics production.
How pure is the compressed air from the D Series?
It is certified to ISO 8573-1 Class 0 and completely free of oil and silicone.
What power range does the D Series cover?
Motor power from 37 to 75 kW. The fixed-speed models deliver up to 12.7 m³/min at 7 bar(g).
What is the difference between fixed-speed and RS models?
The RS models are variable speed and use HPM motors. At part load this saves up to 30% energy compared with conventional controls and allows unlimited start-stop cycles.
Is the D Series available air-cooled and water-cooled?
Yes. You choose air or water cooling depending on the application and ambient conditions.
Can I use the waste heat?
Yes, as an option. Heat recovery can produce process water at up to 90 °C.
How do I dry the compressed air downstream of the compressor?
The D Series can be combined with an HOC dryer. It uses the heat of compression and achieves dew points below −40 °C without additional energy.
How much maintenance does the D Series need?
Very little. The coolant is changed every 8,000 operating hours, the main components are easily accessible, and no special tools are needed.
How do I monitor the compressor remotely?
The controller with its 5.7-inch colour display offers Modbus and Ethernet as well as remote access via web server. Cloud-based monitoring is possible via iConn.
Who can help me choose the right model?
We do. We will advise you on which model suits your power, pressure and application. Call us or write to us.

Which compressor suits your application?
There are various compressor models, which differ considerably depending on output, pressure and field of application. Let us advise you to find the best model for your needs.
