Tag: math

Calculating Compressed Air Cost & Savings Made Easy

Published on by Brian FarnoLeave a comment

If you have ever looked through our catalog, website, blog, twitter feeds, or even our Facebook page, you will see that we can almost always put a dollar amount behind the amount of compressed air you saved by installing EXAIR’s Intelligent Compressed Air Products.   No matter which platform we use to deliver the message, we use the same value for the cost of compressed air which is $.25 per 1,000 Standard Cubic Feet of compressed air. This value is derived from average commercial and industrial energy costs nationwide, if you are on either coast this value may increase slightly. On the positive side, if your cost for compressed air is a bit more, installing an EXAIR product will increase your savings.

So where does this number come from?   I can tell you this much, we didn’t let the marketing department or anyone in Accounting make it up.   This is a number that the Engineering department has deemed feasible and is accurate.

To calculate the amount we first look to what the cost per kilowatt hour is you pay for energy.  Then we will need to know what the compressor shaft horsepower  of the compressor is, plus the run time percentage, the percentage at full-load, and the motor efficiency.

If you don’t have all of these values, no worries.   We can get fairly close by using the industry accepted standard mentioned above, or use some other general standards if all you know is the cost of your electricity.

The way to calculate the cost of compressed air is not an intense mathematical equation like you might think.  The best part is, you don’t even have to worry about doing any of the math shown below because you can contact us and we can work through it for you.

If you prefer to have us compare your current compressed air blow off or application method to one of our engineered products, we can do that AND provide you a report which includes side by side performance comparisons (volume of flow, noise, force) and dollar savings. This refers to our free Efficiency Lab service.

EXAIR's Efficiency Lab is a free service to all US customers.
EXAIR’s Efficiency Lab is a free service to all US customers.

If you already know how much air you are using, you can use the Air Savings Calculators (USD or Euro) within our website’s knowledge base. Just plug in the numbers (EXAIR product data is found on our website or just contact us) and receive air savings per minute, hour, day and year. We also present a simple ROI payback time in days.

Now, back to the math behind our calculation.
Cost ($) =
(bhp) x (0.746) x (#of operating hours) x ($/kWh) x (% time) x ( % full load bhp)
——————————————————————————————————————————
Motor Efficiency

Where:
bhp — Compressor shaft horsepower (generally higher than motor nameplate Hp)
0.746 – conversion between hp and KW
Percent Time — percentage of time running at this operating level
Percent full-load bhp — bhp as percentage of full load bhp at this operating level
Motor Efficiency — motor efficiency at this operating level

For an average facility here in the Midwest $0.25/1,000 SCF of compressed air is accurate.   If you would like to attempt the calculation and or share with us your findings, please reach out to us.   If you need help, we are happy to assist.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

 

Where Does 25 Cents For 1,000 Standard Cubic Feet Of Air Come From?

Published on by Brian FarnoLeave a comment

Wasting compressed air 2

Being an Application Engineer at EXAIR you tend to do a good amount of return on investment (ROI) calculations.   This is mainly to tell customers just how fast installing an EXAIR product on their system is going to pay its purchase price back and start saving them money.

In order to do these calculations there are several variables we must know.   The list is below.

  • Cost of EXAIR Product (This is an easy one for us to know.)
  • EXAIR Product Consumption (Another easy one!)
  • Current Product Consumption (If this is an unknown, we will test it for free!)
  • Cost of Compressed Air / 1,000 SCF (This is the most common unknown.)

With these four variables we can calculate the amount of air and the amount of money the EXAIR product will save over an existing non-engineered blowoff.   Let me address the two variables which have to come from you, the customer.

Current Product Consumption – If this value is not known please don’t guess at it.  We offer a free service which we refer to as our Efficiency Lab where you send us in your existing blowoff device and we will test it for force flow and noise level.   If you don’t know what pressure you are operating the piece at we will help you find out how to get that and then we will test our products at the same pressures.   This way you get a true apple to apples comparison.   Then, once we are done testing, you will get a recommendation from us in a formal report as to what EXAIR product will best replace your existing product.  Then we will pay for return shipping of your blowoff device back to you. So, if you don’t know how much air you are currently using then give us a call.  We will figure it out for you.

Efficiency Lab
The EXAIR Efficiency Lab is FREE!

Cost of Compressed Air/ 1,000 SCF – This is more often than not, the unknown variable in the equation.  The good news is there is a general standard assumption of twenty-five cents per 1,000 Standard Cubic Feet of compressed air.   This works out to be around 8 cents per kW/hr.  So even if you don’t know what you pay to compress the air, if you know what you are paying per kilowatt hour for your energy then we can calculate within reason what it costs for you to generate your compressed air. For reference, 8 cents per kilowatt-hour falls between the average US cost per kilowatt hour for commercial end-users (10.7/kWh) and industrial end-users (6.9/kWh).*

The best part of all is…EXAIR has a calculator available right on our website which provides air and dollar savings per minute, hour day and year as well as a payback in days for the EXAIR product purchase. On top of that, any step along the way that you aren’t sure of, we will help you out for free, even testing your product!

In case you would like to see the math, the formula used is below.

Basic Equation To Go From Cost Per kiloWatt Hour to Cost Per 1,000 Standard Cubic Feet of Compressed Air
Basic equation to go from Cost Per kiloWatt Hour to Cost Per 1,000 Standard Cubic Feet of Compressed Air

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

*latest U.S. EIA report here

 

 

 

How Much Force Does It Take?

Published on by Brian FarnoLeave a comment

In case you weren’t aware, the answer to “How much force does it take?” is always going to be, ALL OF IT.   At least that is what we generally think when trying to blow product off a conveyor belt or diverting parts into bin, etc. Speed and efficiency play a direct role in to what nozzle or blow off device you should use in order to get the job done and be able to repeat the process.

The question we are often asked by customers is, “How much force to I need to move this?”  That is a question that we cannot often answer without asking more questions.  The good part of this is, there is a formula to calculate just how much force you need to move an object.   A good video explaining friction is shown below.

In order to answer the question of how much force do I need, we really need to know all of the following:

Weight of the object
Distance from target
Is it on an incline or level
Distance needed to move
Then, the usually unknown variable, the coefficient of friction between the target and what it is sitting on.

Often times it is the thought process of, my target weighs 5 pounds, I need 5 pounds of force in order to move it from the center of this conveyor belt to the edge, this is not the case.   If you wanted to lift the object over a break between two conveyors then you would need slightly more than 5 pounds in order to ensure you are lifting the front edge of the unit high enough to meet the other conveyor.

Whether you know all of the variables or only a few, if you need to get an object moved and you want to try using compressed air to do so, give us a call and we will help you find the best engineered solution for your application.  Then, we’ll back all stock products with a 30 day guarantee if you don’t like how the system performs – but rest assured, we get it right almost every time.

30 Day Guarantee
The EXAIR 30 Day Guarantee

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

Algebra!

Published on by Russ BowmanLeave a comment

algebra

I know a great many people that this meme applies to. My co-workers and I, however, are not among them. As Application Engineers, we use algebra all the time, and we all (as far as I know) like it. For instance:

-We publish the compressed air consumption of most of our products assuming a supply pressure of 80psig. If you want to know what it is at a different pressure, you can go get a flow meter*, install it in your supply line, regulate your pressure to the desired point, and hope your flow meter is calibrated. Or, you can call us…and we’ll use algebra.  While you wait.

*Some flow meters are rated for a certain pressure, so to recalculate the flow at another pressure, you have to use algebra anyway. Ain’t that a kick in the teeth?

-We take great pride in our ability to quickly and accurately specify the appropriate Cabinet Cooler System for your electrical enclosure, if you can give us just a few key pieces of information. We do this using algebra.

Math doesn’t give us the answers to all the questions we get…and that’s not always a bad thing:

Super Air Knife selection often simply comes down to the length of the air “curtain” that you need. We stock them in lengths from 3”-96”, and they can be coupled together for any greater length you want.

Our selection of Super Air Nozzles offer a wide range of air flow patterns and force. Whether you want to blow 2 ounces of force in a 2” pattern, 23 pounds of force in a 15” pattern, or anywhere in between, we’ve got a wide variety to choose from.

If you’d like to know which EXAIR product is right for your application, we’ll be happy to help. Even (or should I say “especially”) if it requires the use of algebra.

Russ Bowman
Application Engineer
EXAIR Corporation
(513)671-3322 local
(800)923-9247 toll free
(513)671-3363 fax
Web: http://www.exair.com
Blog: http://blog.exair.com/
Twitter: twitter.com/exair_rb
Facebook: http://www.facebook.com/exair