Considerations for Medical Compressed Air Systems

When hospitals and medical facilities need Medical Air compressed air systems, there are many factors to consider. First and foremost, all systems must meet the requirements set forth in the NFPA 99 specifications. Aside from the standards laid out by the NFPA 99, there are some other things to consider.

amico duplex 20hp scroll system facts about medical air compressors




  • Compressor Technology: Different technologies can be used for compressed air in a medical system. Currently the most widely used is the oil-less reciprocating and the oil-less scroll.  The oil-less scroll is a great choice because of its lower operating costs and extended service intervals.  Having a smaller size, scroll pumps can be banked with multiple units, allowing the system to meet the varied demands of a hospital saving energy costs during periods of lower demand.
  • Noise / Heat: Usually a compressed air system is not the only piece of equipment in the mechanical room. Excessive noise and heat can be issues.  An enclosed scroll system can offer the advantages of reduced noise levels. Also with an enclosed system you can duct in your cooling air and duct out the hot exhaust air.
  • Controllers / Connectivity: An integral part of any Medical Air compressed air system is the controller. Things to consider would be Ethernet connectivity, integration with your building automation systems (BACnet Protocol) and email notification for service personnel.
  • Reliability / Serviceability: Even with the stringent requirements from the NFPA 99, not all systems are built the same. Close attention needs to be paid to the expected reliability of the system and how it is engineered.  Check the manufacturer’s warranty and see what is covered and for how long. Some manufacturers are submitting their systems to seismic testing and certification.  We now have seismic certifications available for all of our source equipment.  No matter how well a system is engineered and built, you’ll still need service for it so make sure there is local support with technicians that are ASSE 6040 certified.


Written by Darren Brown: Medical Systems Consultant for Lewis Systems.  Darren has over 30  years in the Med Gas and Oil-Free compressed air industry.  

Kobelco KNW Series Unique Features

kobelco knw oil free air compressor

Recently we looked at some of the benefits of switching to Oil-Free compressed air.  Moving to an Oil-Free compressor can have a significant impact on your cost of ownership, but like most capital expenses, you’ve got to do your research before you buy.  Let’s take a look at the Kobelco KNW Series and see what unique features set it apart from the competition.

Kobelco KNW Series Oil Free Air Compressor

kobelco knw series oil free specs

  • Heavy Duty Air End Design – a patented, high-efficiency super rotor profile. Rotors, shafts and compression housing all have a PTFE coating to protect against corrosion and wear.  Thrust balance pistons on each stage provide maximum air end life.  These are not found on competitive models.
  • Pre and Post Lubrication of Gears & Bearings – an independent motor-driven gear pump provides lubrication prior to start up, during operation and shutdown. A unique feature of the Kobelco KNW Series that increases gear and bearing life.
  • Heavy Duty Input Bull Gear – input bull gear is supported on each side along with a labyrinth type seal used on the drive end. Competitors use an overhung design as well as lip seals, which are prone to wear and leakage.  The KNW design ensures a long operating life and eliminates oil leaks.

If you’re looking for a quality oil free brand, Kobelco KNW should be at the top of your list. Learn more about the KNW series here.

Why You Need to Evaluate Your Energy Efficiency

The way compressed air is made has not changed for many years. The oil flooded rotary screw is by far the most popular method and is the industry’s standard today. What has changed is the technology and improvements in rotor design, compressor controls, motor efficiency and variable speed drives. Most plants are running the same compressors they purchased 15 to 20 years ago and most are running more horse power than they need. Even though your compressors are doing a great job and are very reliable, there are ways to make them run more efficiently.

Power Consumption Graph

Power Consumption Graph

Master Controller - Used to control all compressors in the most energy efficient cycles

Master Controller – Used to control all compressors in the most energy efficient cycles

The first step is to have your compressed air system evaluated. A Level I evaluation consists of a job site visit and a walk through of your compressor room and plant. This is done free of charge.  Helpful recommendations can sometimes be made from this evaluation. We are looking for the following: How are your compressors operating? Load/No Load or Modulation control. Do you have enough air storage capacity? Is your air piping adequate? Will a master controller or a flow control valve work for your plant? Would a variable speed compressor work best? All these items are addressed during the visit. If we feel it’s necessary, we will recommend a Level II air study or energy air audit. This study will determine exactly how much cubic feet per minute (cfm) your plant is using. Our data loggers will be installed and take readings every 12 seconds for one week. We are measuring and logging flow (cfm), k/W (compressor amps), and plant pressure (psig). From this we can determine how efficiently your compressors are operating and how energy efficient we can make your plant operate after our recommendations are implemented. A return on investment (ROI) is also determined.


Your air compressors are one of the greatest energy users in your plant. If you can cut the cost of producing compressed air by 15% to 20%, you can see significant savings in overall costs. To get started, contact your local branch and request a Level I evaluation today.

Benefits of Oil Free Air Compressors

oil free compressed air The use of oil free air compressors has become an absolute must for certain industries such as hospitals, labs, pharmaceutical companies and semiconductor manufacturers, but there is a growing number of other industrial manufacturers that are realizing the benefits of switching to oil-free air compressors. Using oil free air compressors enables you to provide the highest quality air for your manufacturing needs. In doing so, you can dramatically reduce your operation’s negative environmental effects. Eliminate harmful emissions, conserve natural resources and get a clean, reliable, cost-efficient source of air supply. Along with the positive environmental impact, switching to oil free air compressors can have a significant impact on your cost of ownership.

Oil Free compressors can reduce operating costs by:

  • Eliminating the cost to collect and dispose of oil laden condensate
  • Eliminating the cost of replacing air/oil separator elements and downstream filtration required to remove oil aerosols
  • Eliminating oil contamination and costly replacement of desiccant in regenerative air dryers
  • Eliminate the potential for compressed air pipeline fires caused by oil carry-over
  • Eliminate the cost of ruined products, lost production and damaged reputation
  • Eliminate high energy cost

OilFreeCompressedAirIndustriesLewis Systems & Service Co., Inc represents the best in oil free compressed air. We would be happy to review your compressed air needs to discover if a switch to oil-free would be right for you.

Already have an oil free air compressor? We can service them and get you the parts you need. We have certified technicians with years of experience on Gardner Denver, CompAir, Kobelco, Hitachi, Powerex and Cooper Cameron just to name a few. Contact us today.

Common Types of Air Compressor Repair

Lewis Systems & Service Co., Inc. not only sells new and used air compressors but a good part of our business is based around air compressor repair and servicing. Below is a list of some common air compressor repairs that we address in the field. This is not a troubleshooting guide or instructions on how to do repairs, however if your unit is serviced on a regular basis, a lot of these problems can be prevented.

Reciprocating Compressors:air compressor repair tips

  • Rings – As the piston rings wear out, excessive oil consumption will rise.
  • Valves – Carbon deposits can build up on the valves causing the compressor to take longer to build up pressure. They usually need regular cleaning or replacing if damaged.
  • Controls – Defective pressure switch can cause starting problems as well as a faulty check valve. Problems with the pilot valve can cause the compressor not to unload properly.
  • Belts can be too tight or too loose, also the pulley could be out of alignment causing excessive wear on the belts.
  • Air intake filters should be inspected and changed on a regular basis. Dirty air filters can cause long pump up times and overheating.
  • Routine Maintenance Items: Changing the air filter and oil on a regular basis will prevent many problems. It will also extend the life of valves and rings.

Rotary Screw Compressors:common types of air compressor repair

  • Controls / Check Valves: The majority of problems that arise on rotary screw compressors are related to the controls and sensors. A faulty pressure transducer or a sticky thermal valve element can shut your compressor down very quickly. It’s always good practice to have these items in stock or at least know a reliable service center (we suggest Lewis Systems), that normally has these items in stock.
  • Not Building Pressure: Number one cause: a dirty inlet air filter. Also problems with the inlet valve or minimum pressure valve. Both should be inspected and cleaned on a regular basis. Both normally have packing rings or seals that need to be replaced occasionally.
  • Inlet Valve Maintenance
  • Excessive Oil Carryover: A common cause for oil carryover is a blocked or faulty scavenge line check valve. Oil separators can rupture if they are not changed on a regular basis which will cause oil carryover as well.
  • Routine Maintenance Items: Changing the air filter and oil filter on a regular basis will prevent many problems. It will also extend the life of the compressor lubricant and oil cooler.
  • As you can see, there are lots of maintenance and repair issues that should be addressed on your air compressor. Don’t forget that Lewis Systems & Service Co., Inc. has a fully staffed service department at each of our locations to assist you. From emergency repairs to proactive maintenance agreements we can help keep your plant up and running.