Intelligent Compressed Air: Refrigerant Dryers and How They Work

We’ve seen in recent blogs that Compressed Air Dryers are an important part of a compressed air system, to remove water and moisture to prevent condensation further downstream in the system.  Moisture laden compressed air can cause issues such as increased wear of moving parts due to lubrication removal, formation of rust in piping and equipment, quality defects in painting processes, and frozen pipes in colder climates.  The three main types of dryers are – Refrigerant, Desiccant, and Membrane. For this blog, we will review the basics of the Refrigerant type of dryer.

All atmospheric air that a compressed air system takes in contains water vapor, which is naturally present in the air.  At 75°F and 75% relative humidity, 20 gallons of water will enter a typical 25 hp compressor in a 24 hour period of operation.  When the the air is compressed, the water becomes concentrated and because the air is heated due to the compression, the water remains in vapor form.  Warmer air is able to hold more water vapor, and generally an increase in temperature of 20°F results in a doubling of amount of moisture the air can hold. The problem is that further downstream in the system, the air cools, and the vapor begins to condense into water droplets. To avoid this issue, a dryer is used.

Refrigerated Dryer

Fundamental Schematic of Refrigerant-Type Dryer

Refrigerant Type dryers cool the air to remove the condensed moisture and then the air is reheated and discharged.  When the air leaves the compressor aftercooler and moisture separator (which removes the initial condensed moisture) the air is typically saturated, meaning it cannot hold anymore water vapor.  Any further cooling of the air will cause the moisture to condense and drop out.  The Refrigerant drying process is to cool the air to 35-40°F and then remove the condensed moisture.  The air is then reheated via an air to air heat exchanger (which utilizes the heat of the incoming compressed air) and then discharged.  The dewpoint of the air is 35-40°F which is sufficient for most general industrial plant air applications.  As long as the compressed air stays above the 35-40°F temperature, no further condensation will occur.

The typical advantages of Refrigerated Dryers are-

  1.  – Low initial capital cost
  2.  – Relatively low operating cost
  3.  – Low maintenance costs

If you have questions about getting the most from your compressed air system, or would like to talk about any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Intelligent Compressed Air: Save $$ With a Leak Prevention Program


Don’t let leaks drive up your utility bill

The generation of compressed air accounts for approximately 1/3 of all energy costs in an industrial facility. According to the Compressed Air Challenge, about 30% of that compressed air is lost through leaks. This means nearly 10% of your facility’s energy costs are simply wasted through poor connections, faulty air valves, improper installation, etc. In addition to simply wasting money, compressed air leaks can also contribute to a variety of other operating losses. A leak can cause a drop in system pressure. When this occurs, end users may not operate as efficiently, having an adverse effect on production. This same drop in system pressure will also cause the equipment to cycle on/off more often, shortening the life of your compressor and other equipment. If the leaks cause an issue in supply volume, it may lead to the belief that more compressor capacity is necessary, further increasing your operating costs.

To put leaks in perspective (assuming energy costs of .10/ kWh), the Compressed Air Challenge states this:

  • A $200/year leak cannot be felt or heard
  • A $800/year leak can be felt, but not heard
  • A $1,400/year leak can be felt and heard.

If you walk through your facility, how many leaks can you hear?

We know that a large portion of the compressed air is being wasted, but what do we do about it? A proper leak prevention plan is the key to success. Since these leaks are impossible to see and some cannot even be heard, you need a tool to help assist you. EXAIR’s model 9061 Ultrasonic Leak Detector is the right tool for the job. When compressed air leaks through a pipe, it creates an ultrasonic signature due to turbulence. While this sound is not always detectable by the human ear, this meter will allow you to locate leaks up to 20’ away.



Model 9061 with parabola attachment

The first step will be locating the leaks using an Ultrasonic Leak Detector and tagging them throughout the facility. Don’t let this overwhelm you!! If you have a larger facility, break it up into sections that can be completed in 1 day. This will allow you to decide which areas of the plant should be looked at first. Once you’ve located and tagged all of the leaks, rate them under two separate criteria so that you can prioritize what to fix first. Rate them based on the difficulty that it will take to fix them and also by the severity of the leak. Those that are severe yet easy to fix would make sense to begin fixing first. Those that may require a period of shutdown can be planned to fix at a more appropriate time.


Accessories that come with the Ultrasonic Leak Detector

When you’ve had the opportunity to fix them, don’t just forget about it. When new piping is installed, new lines are added, or anything involving compressed air is installed there is the potential for new leaks to develop. Set this as one of your regular PM activities and complete your own compressed air audit once a year. Implementing the process and maintaining it are the keys to your success.

If you have questions about developing a leak program or how to use the Ultrasonic Leak Detector, give us a call. An Application Engineer will be happy to help with the process and recommend additional methods to save on your compressed air supply.

Tyler Daniel
Application Engineer
Twitter: @EXAIR_TD

Social Media Finds Lost Dogs, Helps Save Compressed Air

Lost Dog – Her name is Molly


The versatility of  social media is one of its greatest assets. If you have an interest in something you can most likely discover others with the same interests on one of the social media platforms. From Facebook, Twitter, blog posts, LinkedIn, Google+ and YouTube to Pinterest, Flickr, Instagram and Reddit – you will be hard pressed to NOT find something you are looking for.

The other day, we lost our dog, and it was a traumatic experience for us.  She saw some deer in the backyard; and in her crazed state, she knocked down the pet gate.  Molly went after the deer into the woods behind our place.  Being that it was raining and approaching the evening hour, I mentioned that when she gets done hunting, she will come back home.  We placed her bed and food onto the porch for when she returned.

The next day, Molly was not on the porch.  We were disheartened.  Being that I am a bit “old” school, we decided to print some flyers with Molly’s picture.  After I returned from work, we started in my neighborhood and worked our way out.  We drove to all the neighbors to see if they had seen her, and we stapled the flyers to telephone poles and community boards.  We were going at it for hours, and it seemed to be getting hopeless.  (Now, I would not have written this blog if it had a sad ending.)

As we continued to make our journey, I went up to a house and knocked on their door.  A gentleman answered, and I gave him the story of how our dog got out of her pen.  As I was still speaking, my significant other rolled down her window and shouted to me that she found Molly.  I was a little confused as I headed back to the vehicle.  She told me that a picture of Molly was on her Facebook.  (Of course Molly was making herself right at home as the picture showed her laying on a couch).  We were extremely happy that we had finally found her.  Apparently, a lady that found Molly posted her picture, and tagged her friends.  Her friends then sent it out to their friends, and before you knew it, we had her picture on Facebook.  With a friend request, we were able to receive her location and start our way to pick her up.  Believe it or not, Molly was over 2 miles away from our house.

Being curious, I looked at the timeline of the post.  I noticed that she posted the picture at 6:44 p.m., and we were looking at Molly at 7:28 p.m. that same day.  This was definitely much quicker and easier than hanging flyers and knocking on doors.  I was amazed at how fast and simple that this social networking reunited us with Molly.

This got me thinking about social media.  Facebook is the largest social network with almost 2 billion users throughout the world.  In looking at the nature of Facebook, it is more than reuniting with friends or finding lost dogs.  It also unites companies.  EXAIR has a Facebook page in which we post videos, photos, and blogs of compressed air solutions.  We can show you how to save money by using less compressed air with our products and how to solve every day problems with your compressed air system.  We would love to have you as a friend at  We may not be able to find your dog, but we sure can share some stories, solve compressed air problems, and become good friends.

John Ball
Application Engineer

Twitter: @EXAIR_jb



Pet Peeve: Lights On In An Empty Room

As the father of two sons, I spend a lot of time telling them to turn off the lights in their rooms when they leave them. I also spend a lot of time turning the lights off in their rooms after they’ve long left them. To their credit, though, they’re both pretty good about putting away their clean clothes, getting their dirty laundry to the hamper, clearing the dinner table, etc…they do give me a lot to be proud of, responsibility-wise, so flipping a light switch a couple times a day isn’t so bad, all things considered. As I wrote about a while back, the electric company gave me a bunch of CFL light bulbs, which I promptly installed throughout the house, so I’m really getting off light (pun intended.)

Compressed air users don’t get so lucky, though…in fact, turning off compressed air flow when it’s not needed is among the most valuable of the “Best Practices for Compressed Air Systems,” as published by the fine folks at the Compressed Air Challenge. And this is where the compressed air users’ luck can change by using EXAIR’s EFC Electronic Flow Control.

The EFC is a system consisting of a programmable timer which opens and closes a solenoid valve, based on input from a photoelectric sensor. A typical installation might be on a conveyor belt, where gaps exist between parts that are being blown off by a compressed air device like an Air Knife, Air Nozzle, Air Amplifier, etc. The sensor would be mounted to “see” the parts when they’re in position for blow off…when one is there, it’ll open the solenoid valve. When the part has passed, it closes the valve.

If your application isn’t quite so “cut and dry,” the timer has eight modes of operation to choose from, and the time scale is adjustable down to a tenth of a second. For more details on this, Lee Evans made a fine video that explains it all.

If you have a blow off that doesn’t need to be continuous, then the EFC is just what you need. For selection assistance, contact an EXAIR Application Engineer – we’re eager to help!

Russ Bowman
Application Engineer
EXAIR Corporation
(513)671-3322 local
(800)923-9247 toll free
(513)671-3363 fax

The Last Of The Compressed Air Challenge Seminar Blogs (for now)

Last week, Lee Evans, Brian Farno, and I attended a seminar entitled “Fundamentals of Compressed Air Systems,” sponsored by the Compressed Air Challenge. Lee and Brian have already written great pieces on what we learned, and Joe Panfalone (even though he didn’t even go) has gotten in on the action too – leaving me to search desperately through my notes for something relevant to discuss. Here’s my initial takeaway: If your blog is published on Wednesday, try to attend the seminar you wish to write about on Tuesday, not Thursday.

One thing that my associates left me, though, was the subject of inappropriate uses of compressed air. According to the Compressed Air Challenge folks, 70% of the savings to be realized lie in measures on the “demand” side of your system. A big chunk of this is the aforementioned inappropriate uses, which were defined as applications that could be performed using alternate methods. The assumption is that these alternate methods are less costly from a compressed air usage standpoint – which is not always the only factor to consider:

*The floor needs to be swept at the end of the shift. It takes 10 minutes with a broom, or 5 minutes with a Super Blast Safety Air Gun (for instance, the Model 1214, which uses 91 SCFM @80psig). Let’s assume labor at a cost of $50/hr, and compressed air at a cost of $0.25/1000 SCF (Standard Cubic Feet):

-Broom: $4.17 labor (10 minutes @$25/hr) = $4.17
-Air: $2.19 labor (5 minutes @$25/hr) + $0.11 compressed air = $2.19

Other situations require a little more data, and math, to quantify. For instance, if vacuum is required for lifting, pick and place, mounting, etc., a central vacuum pump may have lower operating costs than those associated with the compressed air needs of E-Vac Vacuum Generators. When you factor in initial capital cost and maintenance expenses, the E-Vac still compares favorably, though, despite the potentially higher operating cost. I say “potentially,” because a system’s vacuum pump is often located some distance from the farthest point of use. That means it’s spending energy not only to provide vacuum to the remote points of use, but also to overcome the line loss in those lengths of piping. E-Vacs don’t have this problem, as they can be easily installed at the point of use, and sized appropriately.

The last (and I thought, most highlighted) inappropriate use they covered was cabinet cooling. It was explained that even though a vortex tube cooler may cost less, the air consumed will cost more than the electricity required by a refrigerant-based unit. Now, we don’t dispute that…the following comparison shows as much:

Then, the instructor went a bit further (pre-empting a question from Brian, Lee, and I) to validate cabinet cooling as an appropriate use, but only when: the environment was not conducive to a refrigerant-based unit (high ambient temperatures, dusty/dirty/aggressive atmosphere, etc.), AND thermostat control was used. They took great pains to not promote any particular brands of equipment in the presentation of the seminar, but the photo they used to illustrate this was unmistakably an EXAIR NEMA 4 Cabinet Cooler with Electronic Temperature Control. That was worth the price of admission for me.

If you have questions about whether you’re using your compressed air appropriately, or even to its maximum efficiency, give us a call. If we can’t find the answer mathematically from the data available, we can gather the data in our Efficiency Lab. Math doesn’t lie, and neither will we.

Russ Bowman
Application Engineer
EXAIR Corporation
(513)671-3322 local
(800)923-9247 toll free
(513)671-3363 fax

Compressed Air Challenge

A few of us in the engineering department are attending the Compressed Air Challenge today.  The Compressed Air Challenge is a seminar which highlights the operation and optimization of compressed air systems.  Being that those subjects go hand in hand with EXAIR products and practices, we hope to not only attend and learn, but to contribute, given the opportunity.

One of the subjects to be covered is the impact of different compressor controls.  Many compressors use feedback control systems to either throttle the amount of intake air supplied to the compressor (known as modulating system control or throttling), or to reduce the compressor displacement/speed to accommodate for system load ( known as variable displacement/variable speed control, respectively).

These optional control systems can save energy costs by responding in real time to the needs of the system.  For example, if a compressed air flow of 100 SCFM at 80 PSIG is required for 2 hours of the workday and after this initial use only 50 SCFM at 80 PSIG is required, a variable speed compressor can accommodate for this change by adjusting the speed of the electric motor driving the compressor.  In this example the motor speed will lessen and the required electrical demand to product the required compressed air will lessen as well.  All the while, maintaining adequate compressed air pressure and flow.  I’m looking forward to learning more about these feedback systems.  These control systems do the same thing as an EXAIR product, they optimize and save compressed air costs!

If you have any questions about your compressed air applications or how EXAIR can fit into your current system, give us a call.

Lee Evans
Application Engineer

No Such Thing As A Free…Light Bulb?

Last year, my friendly neighborhood electric company called me up and offered me a free energy audit of my house. It happened to be the day after I got my electric bill, and it had been a long, hot summer, and the bill was proving out my concerns over how much the air conditioning had been running lately. So, I made an appointment.

The auditor gave me some good advice and pointed out a few simple fixes – frankly, some basic home maintenance that I was “planning to get around to eventually.” Then, he surprised me, by going out to his vehicle and bringing in a box full of stuff to make those fixes – a couple rolls of weather-stripping, a “water miser” shower head, and a whole bunch of CFL light bulbs. And it was all free.

But that wasn’t all – while he still had my full attention (free stuff has that effect on me), we sat down and went over a list of incentives they offer to folks who replace older, less efficient equipment with new, high efficiency models – refrigerators, water heaters, and HVAC units were all on that list, as you can probably imagine.

Now, on the surface, it seems like it would negatively affect a company’s bottom line to pay you for taking steps to purchase less of their product, right? Turns out, they’re being incredibly long-sighted. See, as the population increases, so does the number of energy users. Power plants can only generate a finite amount of electricity; when they reach capacity, the only solution is to build a new one. And that costs a LOT of money – more than they can make up for by rate increases (which would be inevitable anyway.) Rather than do that, they would greatly prefer to squeeze every kilowatt they can out of their existing plants, and service every household they can, as efficiently as they can. Power companies across the country are offering similar programs, and if you like free stuff too, I encourage you to seek them out if they haven’t already sought you out.

Of course, they’re not just focusing on residential customers. Increased energy usage efficiency in their industrial customer base is key to the plan as well. If you use a bunch of electric motors, there might be incentives to upgrade to higher efficiency units, and/or install Variable Frequency Drives (if applicable.) Do you have a large shop area? Odds are, it takes a lot of candlepower to light up all that space, and a lot of BTU’s going one way or the other to heat it in the winter and cool it in the summer. Lighting and HVAC are popular incentive programs as well.

EXAIR has worked with several utility companies to provide basic information regarding the savings associated with the use of engineered compressed air products, and I’m preparing another presentation in this regard right now. If you use compressed air, you probably have a good idea of the cost associated. If not, the US Department of Energy has published “Improving Compressed Air System Performance: A Sourcebook For Industry,” which I highly recommend. Additionally, your own friendly neighborhood electric company may offer some assistance, in conjunction with an incentive program. Here is a national database for energy incentives in the U.S.

Whether your concern is for your home or your business electric bill, again, I encourage you to look in to any incentive programs your utility provider may offer. And if compressed air is a factor in your equation, I welcome the opportunity to help you optimize your usage.

Russ Bowman
Application Engineer
EXAIR Corporation
(513)671-3322 local
(800)923-9247 toll free
(513)671-3363 fax

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