Rotary screw air compressors are used across many industries. For example, machine shops, food factories, packaging operations, and many more. The reason for these compressors’ popularity is their low wear-and-tear and their ultra-quiet operation.
In this detailed buyers guide, we are going to go into who uses rotary screw air compressors, the benefits of using such compressors, their cost, and their disadvantages.
Who Uses Rotary Screw Air Compressors?
Rotary screw air compressors have the following industry applications:
- Papermaking and Printing
- Metallurgy and Mining
- Household Appliance
- Medicine and Health
- Petrochemical Engineering
- Electronic and Electrical
- Light Industry and Food
- Textile and Clothing
- Construction and Building Material
- Electric Power
Best Rotary Screw Air Compressors
|QRS15HO-125||54.9 ACFM @ 125 psi||15 HP|
|QRS30HPD||124 ACFM @ 100 psi||30 HP|
|HPDMC 10HP Variable Speed Drive||39cfm@115psi||10 HP|
|PneuTech 20 HP Rotary||23.8 CFM||20 HP motor|
|HPDMC Model SC37A||219 CFM||50 HP motor|
|Atlas Copco GX4||16.5 CFM||5-HP|
1. Chicago Pneumatics QRS15HO-125 – Best Rotary Screw Air Compressor For The Money
Worldwide Chicago Pneumatics is well known for its air compressors. They offer a range of products for every application and will do custom design.
Chicago POnewumatic designs the QRS (Quiet Rotary Screw) line of air compressors specifically for the aftermarket automotive industry.
Its extremely quiet operation, sound attenuating cabinet, and easy to locate footprint makes the QRS rotary air compressors ideal for busy body shops or repair shops.
The entire package of rotary screw air compressor, refrigerated air dryer, and ASME tank can be easily situated in a working shop without special enclosures.
In the QRS line of fixed speed compressors, Chicago Pneumatics provides a feature-rich line of rotary screw air compressors that can meet the demands of any job or shop.
- Low Sound enclosures
- 150psig standard
- Continuous operating capability
- 3-phase 15Hp TEFC Motor
- UL approved control panel
- 5-year warranty
- NEMA 1 electrical protection
- Vibration isolated assembly
These air compressors are designed for small to medium-sized installations such as tire shops, paint shops, and auto body repair shops. The Chicago Pneumatic rotary screw air compressor provides quiet operation with low maintenance.
- 15 HP 3-phase motor
- ACFM @ 125 psig – 54.9
- ACFM @ 150 psig – 49.2
- Sound level – 69dbA
Rugged and backed by a global manufacturing operation, the Chicago Pneumatic rotary screw air compressors are not to be overlooked if you need a moderate-sized rotary screw air compressor for your operation.
- Often rated quietest rotary air compressors for their size on the market
- Well-built and well-engineered for long life and low maintenance
- USA Based company with worldwide experience
- Simple operation and installation
- No dryers or filters included in the kit
- Not as well-known as other air compressor manufacturers
2. Chicago Pneumatic QRS30HPD – Quiet Rotary Screw Air Compressor with Dryer
These larger editions of the Chicago Pneumatic rotary air compressors deliver the same quality and efficiency as the smaller editions.
For larger facilities with greater demands for compressed air, the Chicago Pneumatic QRS30HPD provides one of the quietest operating and most economically operated rotary screw air compressors available on the market today.
Chicago Pneumatics delivers on features with the QRS30HPD that make this rotary screw air compressor reliable choices for your shop.
- Low Sound enclosure deign
- Wye-Delta low amperage start
- ES3000 microprocessor controller
- Continuous duty operation
- TEFC Motor
- NEMA 1 Electrical protection
- Vibration isolation assembly
- Integrated dryer
- Include discharge coalescing filter
- Belt drive system for easy maintenance and smooth operation
The ES2000 controller that is included with the Chicago Pneumatics QRS rotary air compressors is a state-of-the-art microprocessor-controlled unit that is engineered and programmed to manage your rotary screw air compressor for the most efficient operation.
The ES2000 system not only operated the compressor for the most economical delivery of compressed air, but it also intelligently monitors the entire compressed air system to protect the compressor from damage.
The basic specifications on the Model QRS30HPD rotary screw air compressor are equally impressive.
- 30 HP motor
- 3-phase power
- ACFM @ 100psi – 124
- ACFM @ 125 psi – 117
- ACFM @ 150 psi – 104
- ACFM @ 175 psi – 91
- Sound level – 74 dbA
These impressive rotary screw air compressors are also available as variable speed units. Chicago Pneumatic offers an exceptionally wide range of options to ensure that the compressor you get fits your needs perfectly.
- Integrated dryers and filters
- Highly efficient electronic controller included
- Relatively low noise
- Great airflows across the delivered air pressure ranges
- Not as efficient as some other air compressors
3. HPDMC 39CFM 150PSI – VSD Screw Air Compressor
HPDMC is a California based company that is heavily involved in research and development of new air compressor technology and delivering it to the market.
What sets HPDMC Rotary Screw Air Compressors Apart
HPDMS uses permanent magnet motors to drive their air compressors. The company cites many advantages of using permanent magnet technology.
- Less electricity use in running the motor
- The permanent magnet motor design maximizes efficiency
- Allows variable speed operation
These are the same motors used in most electric cars.
The technology has been adapted to provide long running and exceptionally efficient operation. The list of features shouldn’t be overlooked either.
- Long-life V-Belt drive design or direct drive
- High-efficiency air intake filter
- Specially designed silent enclosures to reduce vibration and noise
- 80dbA working noise level
- Two-stage rotary screw reduces the load on the bearings to increase life and lower maintenance
- Modular computer-based control system for more savings on energy
The spec sheet for the HPDMC air compressor is as impressive as the technology.
- Capacity – 39cfm
- Working Pressure – 100 – 200psi
- 10HP motor – 3-phase power
- Spin-on air/oil separator
- Air-cooled aftercooler to reduce discharge air temperatures
These innovative air compressors from HPDMC are reliable and efficient. At the heart of your compressed air system, they will provide long life and fewer maintenance costs than most other comparable rotary screw air compressors.
- High-efficiency PM motors
- Compact design for easy installation
- Integrated smart controls allow easy adjustments and regulation
- Clean, compact design
- A little noisy at 80dbA
- No dryer or filters included in the package.
If you need high flow and reliability, then the PneuTech line of rotary screw air compressors will fill your needs.
These rotary screw air compressors are designed for 100% duty cycle and are built from the ground up for reliability and performance.
High Flow for High Demand
PheuTech engineers the RK line of rotary screw air compressors specifically for medium to large industrial and manufacturing applications. These rotary screw air compressors work well in any facility.
The low noise produced by these compressors allows the installation close to the worksite. Large airflow ensures that your shop won’t lack compressed air even at the highest demand times.
The RK line of rotary screw air compressors from PneuTech are fixed speed compressors that come in a range of sizes from 5 to 50 HP. If you need a reliable source of constant air pressure in your shop, the PneuTech RK series of compressors can be the perfect solution.
- Belt drive design reduces vibration
- Easy maintenance and repair
- Wye Delta Start reduces amp draw on startup to save energy and increases the life of the compressor
- Oversized air-oil separator with 3-stage separation delivers clear air down the supply line.
- Compact design reduces the number and length of hoses
- High-tech electronic controller for the most efficient operation
- Built-in lockout switch
- Cabinet filter built into the compressor cabinet for cleaner operating and cooling air
The PneuTech RK series of rotary screw air compressors are rich in the specification department as well
- 20 HP motor
- Delivers 23.8 CFM
- Working Pressure – 125PSI
- Operating noise level – 68dbA
- 3-phase power
- 5-year major component warranty
Users of PneuTech compressed air equipment consistently rate the customer service and support from PneuTech as among the best in the industry.
- Exceptionally high-quality construction and design
- Highly ranked support and service
- Quality design and engineering
- Quiet operation for in-shop use
- Doesn’t come standard with a dryer or filters
5.HPDMC Model SC37A – Efficient Rotary Screw Compressor
When maximum airflow and the most efficient operation are in demand, the HPDMC rotary screw air compressor Model SC37A fills the bill.
This oil-flooded rotary screw compressor delivers an exceptional quality/value ratio making it a superior choice where large capacities of compressed air are needed.
Large industrial applications call for large-capacity air compressors, and the Model SC37A can deliver on that call.
HPDMC compressors are known for their dependable and economical operation. HPDMS has made sure that each of its rotary screw air compressors has the features that you need.
- Long-life v-belt drive design
- High-efficiency air intake filtration
- TEFC motor
- Low noise enclosure design
- Compact easy to install design
The specifications on a standard HPDMC rotary screw air compressor reveals.
- 50 HP motor
- 3-Phase power
- Capacity – 219 CFM
- Working Pressure – 115 PSI
A wide variety of matching accessories for your compressed air supply system are also available from HPDMC. You can depend on HPDMC to provide a turn-key full-service solution to your compressed air needs.
- Small and compact for such a powerful compressor
- Low noise operation for in-shop use
- Easy maintenance belt drive system
- Great before and after-sale service and support
- Dryer installation is separate
6. Atlas Copco GX4 – 53 Gallon Rotary Screw Air Compressor
This model is made by one of the largest compressor manufacturers. It provides a powerful and reliable solution for many small and medium-sized industries.
It can operate in the desert, where temperatures often reach as high as 46 C. Moreover, the pace of its rotary screw adjusts according to the amount of air required to power up the specific tool.
Thus, GX4 is one of the most economical 5-HP air compressors currently available on the market. This unit’s tank size is 53 gallons and it produces 16.5 CFM at 150 PSI.
- Heavy-duty belt drive
- Low-noise rotary technology
- Space-saving horizontal tank
- No electronic drain valve
7. Quincy QGV-40 – Powerful Rotary Screw Air Compressor
Quincy’s QGV-40 rotary screw air compressor has a powerful 40-HP, 460 V electric motor that generates up to 180 ACFM at 75-150 PSI. The variable screw speed option makes it perfect for large, as well as small jobs.
At the heart of all of Quincy’s QGV®️ compressors is a flex-drive air-end with a 100000-hour design that guarantees easy maintenance and reliable operation.
As this is a tank-less unit, it can hold pressure +/- 2 psi. because of its quiet operation at about 68 DB, this model is suitable for use at home and in urban areas. All QGV compressors come with a 10-year exclusive warranty.
- Adjustable screw rotation for added versatility
- 10-year royal warranty
- Very quiet operation at 68 DB
- No tank
8. Eaton 50 HP – 3 Phase Rotary Screw Air Compressor
Eaton Compressor’s 50-HP rotary screw air compressor is a true industrial gem. Its heart is the 3-phase, gear-driven, fixed-speed electric motor.
The Direct-drive function reduces the workload on the pump and the motor drive bearings. This eliminates the need for belt maintenance.
In fact, this system reduces energy demand by one-third. The Tamrotor/GardnerDenver rotary air end is designed with precision in mind.
Moreover, it is covered by one of the longest warranties in the compressed air industry – a full decade! The other parts of the compressor are covered by a 5-year warranty, which is well above the average warranty in the sector.
The PLC Controller
The compressor’s smooth operation is guaranteed by the PLC controller. It monitors the temperature, oil level, and filtration, and alerts the operator if maintenance is required.
When in use, this compressor is surprisingly quiet (79 DB). Yet, it generates 235 CFM and 100 PSI, while the PSI max is set at 145.
What We Like
- Very long warranty
- Extremely energy-efficient
- Very quiet operation
What We Don’t Like
- Not enough info about tank sizes
Types of Rotary Screw Air Compressors
Gas Powered Rotary Screw Air Compressors
Gas-powered rotary screw air compressors offer the benefit of a rotary screw air compressor without having big output hydraulic drive systems on your work truck. You have the portability that lets you get your compressor closer to your work along with that, with add on wheel kits.
Powers Up Multiple Tools
Power heavy air tools and seat beads re-inflate tires on even the biggest and heaviest equipment tires. What is more, you can have up to 185CFM @ 150PSI air pressure at once with a rotary screw air compressor without an air tank or air reservoir.
Who is it Great For?
These rotary screw air compressors are good for applications like rental, monument engraving, post pounding, irrigation service, directional boring, and general construction. They increase gas pressure by reducing its volume.
Compressors are not unlike pumps in that they can transport the fluid through a pipe and increase the pressure on a fluid. Due to the fact that gases are compressible, the compressor also limits the volume of a gas.
Liquids are pretty much incompressible. The pump’s main action is to pressurize and transport liquids.
Mini Rotary Compressor
Mini or micro rotary compressors have applications in robotics, medical devices, “nano-satellites”, and more. The problem with active cooling for photodetectors in “nano-satellites” becomes critical because the majority of space missions, for example, target Earth observation.
With passive cooling, the required temperatures for desired SNR levels are not achieved. Piston compressors used in cryocoolers generate vibrations.
The company VERT Rotors built an ultralow-vibration rotary compressor with 40mm-long screws. This “nano” compressor is an untraditional, conical type comprised of an inner conical screw rotor revolving inside an outer screw rotor.
The need to develop a tiny rotary compressor with high heat removal, compression ratio, and temperature control has become a crucial issue with “nano-satellites” (100x100x100mm – scale, so-called “CubeSats”) and small satellite platforms (1m x 1m x 1m – scale).
An active heat rejection technology is required with increasing power budgets.
The Cheaper Option
Mini rotary screw air compressors are also cheaper than standard ones. If you get lucky with one made in China, you’ll save lots of money. On average, oil-free mini-units deliver 2.7m³/min / 95cfm, 3.6m³/min / 126cfm, and 3.2m³/min/112cfm.
The shipping weight is less than 800 kg, which is quite light. The build quality of mini compressors is good.
Some of them are available in different modifications, come with very detailed tech specs provided by the manufacturer, and are quick to order.
Oil Flooded Rotary Vs Oil injected
The two main types of rotary screw compressors are oil-flooded or oil-injected and gas rotary screw compressors. With the first kind, oil is injected into the compression cavities to facilitate sealing and supply the gas charge with a cooling sink.
The discharge stream is separated from the oil. The oil is cooled, recycled, and filtered. The oil captures non-polar particulates from the incoming air, thereby reducing the particle load of compressed-air particulate filtration.
Normally, some compressor oil spills over downstream of the compressor into the compressed gas stream. In many applications, this is rectified by filter vessels.
Refrigerated Compressed Air Dryers
Refrigerated compressed air dryers are rated to remove more water and oil than coalescing filters that are downstream of air dryers. This is because after the moisture is removed and the air is cooled, the cold air is used to pre-cool the hot incoming air, which heats up the air exiting.
In other applications, this is remedied by the use of receiver tanks that limit the local velocity of compressed air, which lets the oil condense and be removed by condensate-management equipment from the compressed air system.
The Oil Injected Compressors
Oil-injected rotary-screw compressors are used in pneumatic tool operation, crack sealing, and mobile tire service among other applications. All applications that tolerate a low level of oil contamination can use them.
New oil-flooded screw air compressors release oil carryover of <5mg/m3. PAG (polyalkylene glycol) oil lubricants are used by the two biggest American air compressor OEMs in rotary screw air compressors.
As PAG oil dissolves paint, oil-injected compressors are not used to spray paint. Reaction-hardening, dual-element epoxy resin paints resist to PAG oil.
PAG compressors are not great for applications that involve mineral oil greases coated seals, such as air cylinders that do not work with mineral oiler lubricators and 4-way valves. This is because the PAG degrades Buna-N rubber and washes away the mineral grease.
Rotary Screw Air Compressor vs. Piston Air Compressor
Also known as a reciprocating compressor, a piston compressor uses pistons driven by a crankshaft to deliver gases at high pressure. It is a positive-displacement compressor.
The intake gas enters the suction manifold. After that, it goes into the compression cylinder, where a piston compresses it.
The piston is driven in a reciprocating motion via a crankshaft.
Applications include refrigeration plants, oil refineries, gas pipelines, natural gas processing plants, and chemical plants. One specialty application is the blowing of PET (polyethylene terephthalate) plastic bottles.
A lot of seals and bearings were removed in the design of ionic liquid piston compressors. This is because the ionic liquid does not mix with the gas. Service life is much longer than that of a standard diaphragm compressor with minimized maintenance during use.
The energy costs are reduced by as much as a fifth. The heat exchangers we use in a standard piston compressor are eliminated along with the heat where it is generated in the cylinder. Almost all of the energy going into the process is used with very little loss as reject heat.
Why Choose 3-Phase Power?
This is a question that often comes up when operators begin searching for new or replacement rotary screw air compressors. It is a legitimate question and should be explored carefully.
An understanding of 3-phase power systems is important to make an informed decision.
What is 3-phase power?
Three-phase power is probably the most common method of delivering alternating current power through the electrical grid. Three-phase power requires three wires rather than the two wires found in most homes and small shops.
A three-phase system uses three wires, each carrying an alternating current of the same frequency and voltage.
The three alternating currents are each 120 degrees out of phase with the other two wires. The voltage delivered down each wire is 208 volts.
Three-Phase Power Vs Single Phase
There are several advantages to using three-phase power, especially in an industrial setting with larger motors and power requirements.
More Power With Less infrastructure
Compared to a single-phase system using two wires, a three-wire three-phase system can deliver three times the power with just 1.5 times as many wires.
This doubles the power deliver ratio, which means that your electrical delivery system is more efficient and economical. You can get the same power to the place it is needed with smaller wires.
Smoother Power Delivery
Single-phase systems create a trough during each cycle that effectively delivers zero power to whatever device it is operating. This causes a momentary low power situation in the motor that can increase wear and decrease efficiency.
Three-phase power smooths out these troughs and delivers an even constant power that makes motors run cooler and more efficiently, which, in turn, reduces costs.
Motors With Simpler Design
A Three-phases system can produce a rotating magnetic field. This field can be designed to be specific in direction and with a constant magnitude.
These attributes simply the design of electric motors that lowers costs and increases operating efficiency.
Disadvantages of Three-Phase Power
While three-phase power does have its advantages, the disadvantages must also be considered
- More Wiring requirements – A three-phase system required 1.5 times as much wire as a single-phase system resulting in higher installation costs.
- Special Equipment Needs – Three-phase system requires more complex parts such as three-pole breakers, which are more expensive. In addition, special wiring considerations must be made if you need single-phase power in addition to your three-phase power.
- More Complex – Three-phase systems tend to be more complex to design and install than single-phase systems.
Continuous & Uninterrupted Supply
Rotary screw compressors are designed to provide a continuous and uninterrupted supply of compressed air to industrial and construction sites, paint shops, and other businesses.
They are relatively expensive and also quite heavy. For these reasons, we do not recommend you buying one of the bad boys reviewed in the sections above for your home or garage.
Their PSI max ranges between 150 and 175, while the CFM varies between 16 and 235. While all piston air compressors require a tank to store the compressed air, in the big table above we can see some tankless models.