Air Compressors: Savings Found on the Supply and Demand Side

Producing compressed air can be expensive, but it is necessary for pneumatic systems.  And a large part of that expense is wasted energy, in the form of heat.  Waste will add to your overhead and affect your bottom line.  EXAIR has a line of products to help reduce air consumption at the point-of-use to save you money.  This would include replacing open-pipes and tubes with EXAIR Super Air Nozzles and Super Air Knives.  But, let’s look at the supply side inside your compressor room.  The air compressor operates at about 10% efficiency where most of that loss is in a form of heat. 

Wouldn’t it be nice to recover some of that expense?  You can.  By equipping your air compressor with a heat recovery system.  These systems are designed to recover the loss of heat for other uses.  Today, they can recover somewhere between 50% for liquid-cooled compressors to 80% for air-cooled compressors.  The heat can come from the after-coolers, the electric motor, the “heat of compression”, and the oil cooler.  This reclaimed heat can be used to heat water, warm rooms, pre-heat steam systems, and dry parts. 

Let’s create an example.  A company has a 100 HP air-cooled compressor that is running 8 hours per day for 250 days per year.  The heat recovery system will be able to reclaim 60% of the heat to warm city water in the plant.  If the electrical cost is $0.10 per KWh, we can calculate the savings.

Annual Savings:

100 HP * 0.746 KW/HP * 0.6 (reclaim) * 8 hours/day * 250 days/yr * $0.10/KWh = $8,952.00 savings per year.

In practice, reclaiming the maximum percentage may not be cost effective.  Your company can determine the best percentage for heat recovery by calculating the Return on Investment (ROI).  I wrote a blog post that can help you estimate (Click Here)

As mentioned above, EXAIR saves you money and increase efficiency on the demand side.  EXAIR has engineered nozzles to help reduce compressed air usage.  The following is a quick calculation by replacing an open-end blow-off with an EXAIR Super Air Nozzle.  If you have a ¼” (6mm) copper tube, it will use 33 SCFM (935 SLPM) of compressed air at 80 PSIG (5.5 bar).  As a common replacement, EXAIR uses a model 1100 Super Air Nozzle which will use 14 SCFM (396 SLPM) at 80 PSIG (5.5 bar).  With a simple tube fitting, you can mount the ¼” NPT Super Air Nozzle to the end of the ¼” copper tube.  If we use the same pretext as above, we can find the annual cost savings.  With an air compressor that produces 5 SCFM/hp, we can get a cost savings with the Super Air Nozzle.  The difference in air flow at 80 PSIG (5.5 bar) is:

33 SCFM (copper tube) – 14 SCFM (Model 1100) = 19 SCFM savings

Annual Savings:

19 SCFM * 1 HP/ 5 SCFM * 0.746 KW/HP * 8 hr/day * 250 days/yr * $0.10/KWh = $566.96 savings per year per nozzle.

Whether it is on the supply side or the demand side, companies are looking to reduce or reuse the wasted energy to have a more efficient compressed air system.  The heat recovery system is a bit more complex, but should be considered.  The EXAIR engineered nozzles are more simplistic, and they can give you a return on your investment in a short period of time.  If you would like to discuss how to improve your compressed air system from the supply side to the demand side, an Application Engineer at EXAIR will be happy to assist you. 

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

Photo: Idea by Saydung89Pixabay License.

Oil Removal Filters: Never First, Sometimes Last

If you have been around compressed air systems, our blogs, or even optimized installations of point of use compressed air products, you will see point of use filtration in place. These filters come in a plethora of sizes, shapes, and specifications. Here at EXAIR we recommend to always keep a point of use filtration solution in place. This would include an auto-drain filter separator, as well as an oil removal filter.

Oil Removal Filters

So why do we have two instead of one? Could you use just the oil removal filter rather than two? Well, the answer lies in an optimized installation that will also carry with it a lower total cost of ownership. The auto-drain filter separators from EXAIR have a filter element which takes the air to a 5 micron level of filtration. (Except for the model 9004 which filters down to 20 micron.) The Oil Removal Filters have a coalescing filter element which filters to a 0.3 micron level for the finest debris/mists that may be contained within the compressed air stream. One reason for the separation is when a system is oil-free, the finer filtration level may not be needed. Also, by catching the bulk of material with the standard auto-drain filter and then leaving the finer filter to catch the residual amounts liquid that had been finely atomized within the stream of compressed air. This finer filter costs more so using it to catch larger particulate and risking it becoming clogged quicker will increase the total cost of ownership of the point of use compressed air product it is hooked to, hence never first and sometimes last. After the point of use filtration then placing the point of use pressure regulator and solenoid valves are next. This is all a better way to reduce risk of these being damaged from dirt and contaminants in the air lines. Total cost of ownership reductions all point to a better sustainability of any product.

To better showcase the importance of filtration, here’s a brief video I did a while back that visualizes just what one can see out of a compressed air line with minimal moisture introduced.

As you can see, keeping the point of use air filtered protects your process and decreases the total cost of ownership for your compressed air point of use product. If you would like to discuss other ways we can improve efficiency within your facility and help ensure you are getting the longest life out of your products, please contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

OSHA Safety Standards for Compressed Air

Safety should always be a serious concern within industrial environments.  Walk through any production facility and you should see all kinds of steps taken to give a safe workplace to the operators, contractors, and other team members.  Whether this is through a sign showing PPE required to enter an area, an emergency exit sign, a safe walkway, or machine guards.  Safety has become a standard that should never be lowered and there is good reason for that.

EXAIR designs all of our products to be safe and they meet or exceed OSHA standards that are directed toward compressed air safety.  The first is to ensure that an operator or maintenance worker will not be injured through air impinging their skin should they come into contact with an EXAIR product.   This OSHA standard is 29 CFR1910.242(b) claiming that all point of use compressed air products must be regulated to have less than 30 psig of dead end pressure.   This directive is critical for worker safety and the way many blowoffs skirt by is to cross drill holes in the end of the blowoff.

Cross drilled holes may satisfy the dead end pressure standard but it does not address OSHA’s next important compressed air standard about noise exposure, OSHA standard 29CFR1910.95(a).  The allowable noise level standard combined with 30 psig dead end pressure will render many home made or retail nozzles near useless because few, if any, meet both standards.  Again, EXAIR has engineered and designed our Super Air Nozzles to permit 80 psig inlet pressure and still meet or exceed both of these OSHA standards so that the work can still be done by the operators while remaining safe and retaining their hearing.

For a better explanation and demonstration of how our nozzles meet these standards please see the video below.

While I use nozzles and cross drilled pipes as examples within this blog these safety features are designed into every product that EXAIR offers.  This is due to the fact that OSHA, NIOSH, and the CDC do not delineate between a blow gun, blow off within a machine, or even a Cabinet Cooler System.  If the device is powered by compressed air then the two key OSHA standard are in effect due to the inherit dangers of compressed air.

I encourage you now to walk through your facility and try to listen or spot compressed air points of use within your facility.  Then, I ask you to call, chat, e-mail, or tweet an Application Engineer here at EXAIR and let us help you determine the most efficient and safest product to get the work done.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

The Value Of A Pressure Regulator At Every Point Of Use

regulator
EXAIR Pressure Regulator

To understand the value of a having a Pressure Regulator at every point of use we should start with identifying the two types of Pressure Regulators, Direct Acting & Pilot Operated.  Direct Acting are the least expensive and most common (as shown above), however they may provide less control over the outlet pressure, especially if they are not sized properly.  However when sized properly they do an outstanding job.  Pilot Operated Regulators incorporate a smaller auxiliary regulator to supply the required system pressure to a large diaphragm located on the main valve that in turn regulates the pressure.  The Pilot Operated Regulators are more accurate and more expensive making them less attractive to purchase.  The focus of this Blog will be on the Direct Acting Pressure Regulator.

The Direct Acting Pressure Regulator is designed to maintain a constant and steady air pressure downstream to ensure whatever device is attached to it is operated at the minimum pressure required to achieve efficient operation.  If the end use is operated without a regulator or at a higher pressure than required, it result’s in increased air demand and energy use. To clarify this point, if you operate your compressed air system at 102 PSI it will cost you 1% more in electric costs than if the system was set to run at 100 PSI! Also noteworthy is that unregulated air demands consume about 1% more flow for every PSI of additional pressure.  Higher pressure levels can also increase equipment wear which results in higher maintenance costs and shorter equipment life.

Sizing of the Air Regulator is crucial, if it is too small to deliver the air volume required by the point of use it can cause a pressure drop in that line which is called “droop”.  Droop is defined as “the drop in pressure at the outlet of a pressure regulator, when a demand for compressed air occurs”.  One commonly used practice is to slightly oversize the pressure regulator to minimize droop.  Fortunately we at EXAIR specify the correct sized Air Regulator required to operate our devices so you will not experience the dreaded “droop”!

Standard Air Knife Kit
EXAIR Standard Air Knife Kit Which Incudes Shims, Properly Sized Pressure Regulator & Filter Separator

Another advantage to having a Pressure Regulator at every point of use is the flexibilty of making pressure adjustments to quickly change to varying production requirements.  Not every application will require a strong blast sometimes a gentle breeze will accomplish the task.  As an example one user of the EXAIR Super Air Knife employs it as an air curtain to prevent product contamination (strong blast) and another to dry different size parts (gentle breeze) coming down their conveyor.

EXAIR products are highly engineered and are so efficient that they can be operated at lower pressures and still provide exceptional performance!  This save’s you money considering compressed air on the average cost’s .25 cents per 1000 SCFM.

Super Air Knife Performance
EXAIR Super Air Knife Performance Specifications At 5 Different Pressures.

If you would like to discuss Air Regulators or quiet and efficient compressed air devices, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
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