As briefly said on my main rotary screw buying guide page, there are a few compressor manufacturers that are of interest to us. These manufacturers all have different series (or lines) of screw compressors, which differ in capacity, pressure or options (but they are all rotary screw compressors). Some series are for special purposes like ‘heavy duty’ series, or ‘high performance’ series.

The exact difference between the series is not always very clear. I’m sure many were introduced just for marketing purposes.

Anyway, to make sense of the available screw compressors available to you, I have created this overview.

Overview of screw air compressor manufacturers and series / models.


Quincy is a well known manufacturer of rotary screw air compressors. Their compressors are both sold online and through local dealerships.

QGS Series

These are the specifications for the Quincy QGS series:

  • 5 – 100 hp, belt drive
  • 125 – 150 psi
  • 16 – 460 acfm

The Quicny QGS Series is available as tank-mounted or base mounted (on the floor). There is also the option to add an integrated dryer. Starting from the 20Hp model, this series features a digital control panel.

QGD Series

These are the specifications for the Quincy QGD series:

  • 20 – 50 hp, direct drive
  • 100 – 150 psi
  • 90 – 226 acfm

The Quincy QGD series are a more professional series. The digital control panel is standard on all models, plus compressors in this series have the option to be connected to eachother (plc control).

QSB/T Series

These are the specifications for the Quincy QSB/T series:

  • 10 – 50 hp, belt drive
  • 100 – 210 psi
  • 60 – 230 acfm

The main selling point for this series seems to be ‘oversized rotors = long life’. This series runs on a lower speed because of the longer rotors. Can be base or tank mounted (B/T)

QSF Series

These are the specifications for the Quincy QSF series:

  • 50 – 150 hp, belt drive
  • 100 – 150 psi
  • 238 – 998 acfm

This series start where the QSB/T series stops. Only at a lower maximum pressure is lower. They have the same long/lower speed rotors as the QSB/T series.

QGV Series

These are the specifications for the Quincy QGV series:

  • 20 – 200 hp, belt drive
  • 75 – 150 psi
  • 14.3 – 998 acfm

The main selling point of the QGV series seems to be easy maintenance and reliable operation, plus very stable pressure output (+/- 2 psi). Unfortunately, not much is said about how or with what technology this is achieved.

QSI Series

These are the specifications for the Quincy QSI series:

  • 20 – 350 hp, belt drive
  • 100 – 150 psi
  • 90 – 1500 acfm

The biggest compressors from Quincy are in the QSI series. Main selling point (that Quincy makes) is the low cost of ownership and best ROI (return on investment), together with the lowest specific power consumption.

Chicago Pneumatic

Chicago pneumatic offers a wide range of rotary screw air compressors. Like other manufacturers, the smaller models are available online, while the bigger models are only available through local dealers.

Chicago Pneumatic has devided their screw compressors in lots of different series. It’s a little confusing, because they offer different series and models to different countries.

Their main/general website show the CPN, CPM, CPA, CPB, CPC, CPD, CPE, CPF, CPG and CPVS series (as you can see, they know their alphabet :)

But they have lot’s of localized websites. All of the localized country website show different series with sometimes different colors and options. They also know their marketing at Chicago Pneumatic :)

Their USA website shows the following series:

CPN Series

Small, belt-driven air compressors. They are made to ‘be used as an introduction from a reciprocating piston compressor to a rotary screw’.


  • 3 – 15 hp
  • 150 psi
  • 7.8 – 45.4 acfm (at 150 psi)

As you can see, the pressure and capacity are in the same range as reciprocating compressors. But these rotary screw units are better suited for continuous use and will use less energy.

What the exact difference is with the QRS 3-15 series is not really clear from their documentation unfortunately.

QRS 3-15 Series

QRS stands for ‘Quiet Rotary Screw’ (great marketing again!) and the 3-15 stands for 3 – 15 horse power.

These are the specs of this series:

  • 3 – 15 hp
  • 150 psi
  • 8.5 – 47 acfm

Comes with a 60 gallon tank for the 3-7.5 hp models and a 120 gallon tank for the 10-15 hp models.

QRS 3-15 Base Mount Series

Same as above, but without a tank.

The specs are the same:

  • 3 – 15 hp
  • 150 psi
  • 8.5 – 47 acfm

QRS 20-30 Series

In their own words ‘Ideal for automotive and light industrial applications’.

These models come only as base-mounted, as they are too big to fit on a tank. It only consists of 2 models, a 20 hp, a 25 hp and a 30 hp version.

Specifications of this series:

  • 20 – 30 hp
  • 100 – 175 psi
  • 74 – 104 acfm (at 150 psi)

QRS Mini 10hp Series

This is a one-model series. It’s basically the same as the 10 hp form the QRS 3-15 series, but with much smaller dimensions. The pressure and capacity are the same:

  • 10 hp
  • 150 psi
  • 33 acfm

In their own words “ideal for tire shop, maintenance shop, vehicle body, paint shop or automotive dealership”.

CPC / CPD Series

This is their more professional / large industrial air compressor range. It has a electronic microprocessor controller with display. According to Chicago Pneumatic this is a ‘high efficiency cooling’ and ‘low power consumption’ compressor. There is unfortunately no mention of values or used techniques.

The specifications:

  • 40 – 75 hp
  • 100 – 175 psi
  • 150 – 271 acfm (at 150 psi)

CPE / CPF Series

The biggest air-cooled compressor that Chicago Pneumatic has to offer.


  • 100 – 300 hp
  • 100 – 175 psi
  • 421 – 1306 acfm (at 150 psi)

CPVS Series

“VS” stands for “Variable Speed”. Variable speed drives are widely used in compressors for extra energy savings.


  • 20 – 250 hp
  • 60 -157 psi
  • 80 – 1071 acfm

As you can see, this is a large series, which start from 20 hp and goes all the way up to 250 hp. There are some differences between models in this series, like the type of controller and the maximum pressure you get. Also the smaller sizes are belt-driven while the larger units are direct-drive.

Ingersoll Rand

Ingersoll Rand divides their rotary screw compressors according to size on their website. They have ‘small’, ‘medium’ and ‘large’ rotary screw compressors. Each devision is again split up in the different ranges. Here they are:


  • 5 – 50 hp
    • UP5 (50 Hz range)
    • Up6 (60 Hz range)
  • 7.5 – 40 hp VSD
    • IRN x K (50 Hz range)
    • IRN x H (60 Hz range)


  • 50 – 60 Hp R series
  • 75 – 100 Hp R series
  • 50 – 100 Hp TAS R series (TAS = Total Air System = dryer and filters)


  • 250 – 450 hp SSR/M Series
  • 250 – 500 hp SSR/M 2-stage Series
  • 250 – 300 hp SSR/M 2-stage VSD Series

Let’s focus on the main series here: the UP6

UP6 Series

The UP6 series is well known across the USA and spans a wide range of models and options in the smaller rotary screw segment.

These compressors come with or without a “Total Air System”, which is an integrated dryer and filters. Do you need it? It’s probably a good idea to have it. The overall prices is usually cheaper (compared to buying separate components) and it saves a lot of space and installation work.

The UP6 series has a brother, the IRN series, or “Nirvana” series. This is the VSD range of Ingersoll Rand and is basically an UP6 compressor with an added VSD drive.

UP6 Specifications:

  • 5 – 50 hp
  • 115 – 200 psi
  • 16 – 212 acfm

Atlas Copco

Atlas Copco is the biggest air compressor manufacturer in the world. It’s an huge company, that owns many of the well know air compressor brands. Did you know that Chicago Pneumatic, Quincy, BelAir, GrassAir and Alup are all 100% owned by Atlas Copco?

They seem to promote their brands more in some countries and less or not in others. For example, Chicago Pneumatic and Quincy are big and well promoted in the USA and Canada. While Atlas Copco’s own GX and GA series are much more promoted and bought in Europe.

Atlas Copco makes an immense range of compressors of all types and shaped. Their rotary screw compressor ranges are as follows:

GX Series

Very much comparabel in size, looks and performance with the Quincy and Chicago Pneumatic models. Actually, since both Quincy and Chicago Pneumatic are both 100% owned by Atlas Copco, I’m often wandering if these machines are not 100% the same. They look a little different (where the Quincy QGS and the Chicago Pneumatic QRs series looks almost identical!).

For example, I know for a fact that all Grassair rotray screw compressors are made by Atlas Copco by their main compressor factory in Antwerp, Belgium. Everything on the GrassAir compressors is the same as an Atlas Copco, except for the electric motor. They use a slightly less efficient electric motor for the GrassAir compressors.

Probably the same thing is going on with the GX series and the Chicago Pneumatic and Quincy compressors.

The Atlas Copco GX series are made in Italy. And while they are of high quality and offer good performance with little maintenance, they are the ‘little brother’ of the GA series (see next in the list).

GX Specifications:

  • 3 – 15 hp
  • 100 – 175 psi
  • 19.7- 119 acfm

GA Series

The main range of rotary screw compressors of Atlas Copco. Produced in their main factory in Antwerp, Belgium. They also have 1 or 2 plants in China where they make GA’s but those only serve the Chinese domestic market (it is said).

The GA series is very big and exists already for many years, so there are old and new models of some machines and different series withing the GA range.


  • 20 – 675 hp
  • 58 – 200 psi (depending on range/model)
  • 82 – 3217 cfm

GR Series

GR series are like GA series compressor, but with an higher maximum pressure. They are not very often seen, as this is only useful for some specific applications.

Z Series (oil-free)

The Z series are Atlas Copco’s oil-free range of rotary screw air compressors. They are all two-stage compressors, either cooled by air (ZT) or by water (ZR).

Oil free compressors are often used in the petrochemical, pharmaceutical and food and beverage industries. They are way too big for things like paint spraying, a scroll or oil-free piston compressor would be better suitable for that.

AQ Series (water injected)

AQ is a special compressors. Instead of oil-injected it is water-injected.

It had big promises when first launched but now I barely every hear any news about the AQ compressors.

But, which compressor is right for me?

... I hear you ask.

I know I created a long list, and it can be hard too choose the perfect compressor for you!

Again, the first thing you need to know is your required pressure and your required capacity (or capacity range).

When you know those two basic things, you can select those compressors that meet your requirements. Then, make a selection and keep in mind the following:

  • Years of warranty. Some manufacturers give only 1 year, some give 5 years!
  • Cost of maintenance. This is about the same for all manufacturers.
  • Any options you might need (dryers, filters).
  • Energy costs (how energy efficient is the air compressor?)
  • Electrical requirements (voltage available on site, 1 phase or 3 phase, maximum amps).

But also think about things like:

  • How good / fast is their (repair) service? Do they have a 24 hour emergency service? How fast will your compressor be up and running again in case of troubles?
  • How noisy is the compressor? Cheaper compressors are often noisier.
  • What is the normal lifetime of the compressor?