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The single screw compressor is something we have been hearing about. Especially when it comes to chillers’ efficiency and reliability. But what is it? And how does it work?

In this article we want to answer these questions. And we also want to explain how Daikin is playing its part offering a unique technology in the industry.

Click here to go to Daikin single screw solutions.

What is it?

It is a type of gas compressor, that uses a rotary-type positive-displacement mechanism. This compressor replaced piston compressors, which need large volumes of high-pressure air. It is used in chillers providing small to medium cooling load, typically up to 2,100 kW.

How does a single screw compressor work?

Differently form a screw compressor, it uses one main screw mashing with twin star rotors to produce volume matching compression cycle. Due to the main rotor, balanced in both radial and axial direction, the compressor bearing has extremely high reliability. Therefore, its life span can be longer than other screw compressors. The single screw compressor, then, has only three moving parts. As a result of that, it reduces the possibility of failure and keeps operation costs low.

Find a video about Daikin Single screw technology here.

Daikin leadership in compressor development

Daikin has a history of leadership in the field of single screw compressor chillers, which have been installed all over the world for 20 years. Over time, Daikin has introduced and integrated ground-breaking technology directly into the design of its single screw compressor. Constantly pushing its development towards a new and innovative direction.

Technologies like the Variable Volume Ratio (VVR), or the refrigerant cooled inverter technology, for instance, have been directly integrated in the single screw compressor design. All of these technologies have helped increasing compressors and chillers’ efficiency. And have helped doing it with a particular attention to part load.

In fact, because a chiller operates most of its time at part load, to be efficient, it must have a high part load efficiency.

Daikin has considered that. And has also considered the need from the market for always higher efficiency performance, plus the need to comply with regulations. Those are the considerations that have recently led to introducing a completely new single screw compressor design.

Daikin 3rd generation of air-cooled screw chillers

The new single screw compressor is one of the main and most interesting features in Daikin 3rd generation of air-cooled screw chillers.

The new design includes a new screw profile, which ensures the best performance with both R1234ze and R134a refrigerants. The result of this new developement is a substantial extension of chillers’ cooling capacity. That does not sacrifice efficiency and compactness, though. Infact, the new compressor design keeps chillers’ footprint relatively compact and still very efficient. In addition to this, the new design allows to comply with Ecodesign and also F-Gas regulations. In fact, R1234ze refrigerant, which has a GWP as low as 7, gives end users a green alternative to 134a.