## Estimating the Cost of Compressed Air Systems Leaks

Leaks in a compressed air system can waste thousands of dollars of electricity per year. In fact, in many plants, the leakage can account for up to 30% of the total operational cost of the compressor. Some of the most common areas where you might find a leak would be at connection joints like valves, unions, couplings, fittings, etc. This not only wastes energy but it can also cause the compressed air system to lose pressure which reduces the end use product’s performance, like an air operated actuator being unable to close a valve, for instance.

One way to estimate how much leakage a system has is to turn off all of the point-of-use devices / pneumatic tools, then start the compressor and record the average time it takes for the compressor to cycle on and off. The total percentage of leakage can be calculated as follows:

Percentage = [(T x 100) / (T + t)]

T = on time in minutes
t = off time in minutes

The percentage of compressor capacity that is lost should be under 10% for a system that is properly maintained.

Another method to calculate the amount of leakage in a system is by using a downstream pressure gauge from a receiver tank. You would need to know the total volume in the system at this point though to accurately estimate the leakage. As the compressor starts to cycle on,  you want to allow the system to reach the nominal operating pressure for the process and record the length of time it takes for the pressure to drop to a lower level. As stated above, any leakage more than 10% shows that improvements could be made in the system.

Formula:

(V x (P1 – P2) / T x 14.7) x 1.25

V= Volumetric Flow (CFM)
P1 = Operating Pressure (PSIG)
P2 =  Lower Pressure (PSIG)
T = Time (minutes)
14.7 = Atmospheric Pressure
1.25 = correction factor to figure the amount of leakage as the pressure drops in the system

Now that we’ve covered how to estimate the amount of leakage there might be in a system, we can now look at the cost of a leak. For this example, we will consider a leak point to be the equivalent to a 1/16″ diameter hole.

A 1/16″ diameter hole is going to flow close to 3.8 SCFM @ 80 PSIG supply pressure. An industrial sized air compressor uses about 1 horsepower of energy to make roughly 4 SCFM of compressed air. Many plants know their actual energy costs but if not, a reasonable average to use is \$0.25/1,000 SCF generated.

Calculation :

3.8 SCFM (consumed) x 60 minutes x \$ 0.25 divided by 1,000 SCF

= \$ 0.06 per hour
= \$ 0.48 per 8 hour work shift
= \$ 2.40 per 5-day work week
= \$ 124.80 per year (based on 52 weeks)

As you can see, that’s a lot of money and energy being lost to just one small leak. More than likely, this wouldn’t be the only leak in the system so it wouldn’t take long for the cost to quickly add up for several leaks of this size.

If you’d like to discuss how EXAIR products can help identify and locate costly leaks in your compressed air system, please contact one of our application engineers at 800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

## How Fast is your Chip Trapper?

This question came up to me the other day from a customer in the automotive component industry in Monterrey, Mexico. He was interested in a “sump sucker” type of cleaner for his coolant. But he had one stipulation; he wanted to clean his coolant “on the fly” so to speak so he did not have to turn off his CNC equipment to facilitate the cleaning process.

His original inquiry involved a simultaneous in/out function of the coolant being processed through. We could not accommodate him with a machine that was quite in this nature. However, we do have a product that is the next best thing. Basically, as quickly as the coolant is sucked into the barrel of a Chip Trapper, it is being filtered and is immediately ready to be dispensed back into the machining center sump tank. There is one big benefit in doing it this way. That is the user can pull in all chips that accumulate in the fluid at one time to insure a cleaner end product when the coolant is pumped back into the tank. The other way, would involve recycling a lot of coolant that has already gone through the filtering process and so you end up wasting time re-filtering coolant that has already been processed once. If you have a product like Chip Trapper which is available in sizes to hold up to 110 gallons, you can suck all of the coolant out of the machine in less than 5 minutes so it can be filtered and put right back into the sump. The whole process could take place in as little as 10 minutes depending on how much cleaning in the sump area the customer prefers to do.

That means that a coolant tank could be emptied and re-filled again in as little time as it takes for an operator to go on break or to go to lunch. If you are pressed for time to get in and do coolant maintenance on a regular basis, then perhaps the Chip Trapper would be the answer to your maintenance and up-time concerns.

Neal Raker, Application Engineer
nealraker@exair.com

## So many hobbies…. So little time

In case you haven’t read my previous blog posts I tend to blog quite a bit about my hobbies.  I tend to consider myself a jack of all trades, as I like to think I know enough about most subjects to at least get me in trouble.  My hobbies include, motorcycles, marksmanship, anything with an engine, spending time with family, video games, juggling, working on electronics, wood working, car stereos, designing gadgets, and even photography.  Some of my hobbies are projects that I have around my home that are all in some stage of being done.  I tend to float from one to the other when I start to hit a wall on one I will simply walk to another and work on it to help get a fresh mind with the first.  Slowly but surely they all get completed in a timely manner and I’m always pleased with the outcome.

One of the projects I currently have is a 1970’s pinball machine my parents had in their basement.  While it halfway works it is a true wiring nightmare.  This is one project that may get terminated due to the cost of repairs needed.   However, I do love the hum all the electro-mechanical switches make when you kick it on.  It’s not like all the new computerized units where you don’t hear the relays arching and the levers kicking.  I am normally tinkering on this during the winter months when it is too cold to be out in the garage.

The two hobbies that I feel help me to relax and bring the most enjoyment are photography and motorcycles.  That’s why whenever I am out on a ride as soon as we stop the camera comes out.  Or in most cases now, the GoPro gets slapped on the bike before we leave with a full battery and empty memory card.  When at Deal’s Gap last week I was running three cameras, one on my bike, one on the bike my brother in-law was one, and one on my father in-laws Honda Pilot.  Since I was in the lead and I am a little more advanced in riding than the others I was only in their video until we got to the start of Deal’s Gap.

When I was going through “The Gap” there are all kinds of overlooks and views that you can pull off an overlook the Smokeys.  For this trip I was more focused on letting my knee pucks touch that lovely Tennessee asphalt.  Now for the rest of the trip I was the guy behind the camera the entire time.  I was constantly snapping pictures of Madelyn and my wife, Beth, along with all of the in-laws.  I took hundreds of pictures through the week and well over 30 GB of video on the GoPros.

The problem then comes to time to process all of these.  As I type this blog in one window I’m converting the video from my father in-laws trip through Deal’s Gap in another so I can post it to Youtube.  Time seems to be getting less and less available for these hobbies and life doesn’t seem to slow down at all.  I find that most nights I will be sitting on the couch much like Lee Evans was in his blog yesterday, and have a laptop on trying to either weed through pictures or process and edit video.  While this does get stressful because I feel that I am behind on getting videos out and pictures sent to family, it is still relaxing because as I am looking through the pictures or clipping videos I get to relive those moments.  The reason I am always doing this at night after Madelyn has gone to sleep and Beth and I have discussed the days events and what the next day holds, is there is no time like the present for family or friends.  You never know when that time will end.  So whether you’re in the middle of a sentence in your blog, or making that final cut for that furniture project make sure you take a minute to just be together with the ones you love, turn off the phones, TV, and all the other technology.

Brian Farno
Application Engineer / Jack of All Trades
BrianFarno@EXAIR.com
@EXAIR_BF