Why Use EXAIR Super Air Knives: Return on Investment

Return on Investment, or ROI, is the ratio of profit over total investment.  Many people use it to check stocks, financial markets, capital equipment, etc.  It is a quantitative way in determining the validity for an investment or project.   You can use the ROI value to give a measurable rate in looking at your investment.  For a positive ROI value, the project will pay for itself in less than one year.  Any negative values would represent a high-risk investment.  In this blog, I will compare the ROI between an EXAIR Super Air Knife to a common drilled pipe.  Let’s start by looking at Equation 1 to calculate the Return on Investment:

Equation 1:  ROI = (Total annual savings – Total Project Cost) / Total Project Cost * 100

The Total Project Cost is the cost of the product with the labor to install.  In our example, we will use a 24” (610mm) wide blow-off device.  One device will be an inexpensive drilled pipe and the other will be a high-efficiency EXAIR Super Air Knife.  The drilled pipe had (48) 1/16” (1.6mm) diameter holes spaced ½” (13mm) apart.  EXAIR manufactures the model 110024 Super Air Knife with a .002” (.05mm) slot along the entire length.  Both have a blowing width of 24” to cover the conveyor.  The model 110024 has a retail price of $491.00 each.  The cost of the drilled pipe was around $50.00.  What a difference in price!  But, how could EXAIR remain a leader in this industry for over 35 years?

Let’s continue on with the Return on Investment.  The amount of time required to install the Super Air Knife across the conveyor only took a maintenance staff about one hour to mount.  The labor rate that I will use in this example is $75.00 per hour (you can change this to your current labor rate).  The labor cost to install the knife is $75.00.   The Total Project Cost can be calculated as follows: ($491 – $50) + $75.00 = $516.00.  The next part of the equation, Total annual savings, is a bit more in-depth, but the calculation is shown below.

Super Air Knife

EXAIR manufactures engineered products to be efficient and safe.  The Super Air Knife has a 40:1 amplification ratio which means that 40 parts of “free” ambient air is entrained for every 1 part of compressed air.  For comparison, the Super Air Knives are to compressed air systems as LED lightbulbs are to electricity.  In that same way, the drilled pipe would represent an incandescent lightbulb.  The reason for this analogy is because of the amount of energy that the EXAIR Super Air Knives can save.  While LED lightbulbs are a bit more expensive than the incandescent lightbulbs, the value for the Return on Investment is at a higher percentage, or in other words, a short payback period.  On the other hand, the drilled pipe is less expensive to make, but the overall cost for using it in your compressed air system is much higher.  I will explain how below.

To calculate the Total Annual Savings, we will use the same blow-off scenario as above.  The amount of compressed air used by the drilled pipe is around 174 SCFM (4,924 SLPM) at 60 PSIG (4.1 Bar).  The model 110024 Super Air Knife has an air consumption of 55.2 SCFM (1,563 SLPM) at 60 PSIG (4.1 Bar).  At an electrical rate of $0.08 per Kilowatt-hour, we can figure the cost to make compressed air.   Based on 4 SCFM per horsepower of air compressor, the electrical cost is $0.25 per 1000 standard cubic feet, or $0.25/1000SCF.  To calculate an annual savings, let’s use a blow-off operation of 8 hours/day for 250 days a year.   Replacing the drilled pipe with the model 110024 Super Air Knife, it will save you (174 SCFM – 55.2 SCFM) = 121.8 SCFM of compressed air.  To put this into a monetary value, the annual savings will be 121.8 SCFM *$0.25/1000SCF * 60 Min/hr * 8hr/day * 250 day/yr = $3,654 per year.

With the Total Annual Cost and the Project Cost known, we can insert these values into Equation 1 to calculate the ROI:

ROI = (Total annual savings – Total Project Cost) / Project Cost * 100

ROI = ($3,654 – $516.00) / $516.00 * 100

ROI = 608%

With a percentage value that high, we are looking at a payback period of only 52 days.  You may look at the initial cost and be discouraged; but in a little over a month, the model 110024 will have paid for itself.  And after using it for one year, it will save your company $3,654.00.  Some things that may be overlooked are safety issues.  With some inexpensive blow-off devices, the noise levels are over the OSHA limits.  The drilled pipe had a noise level of 91 dBA while the Super Air Knife only had a noise level of 65 dBA.

In my experience, a loud blowing noise from your equipment is generally coming from an inefficient and safety-concerned product.  With these “cheap” ways to blow compressed air, it will cost your company a lot of money to use as shown in the example above.  If you would like to team up with EXAIR to set up ways to increase savings, improve productivity, and promote safety, an Application Engineer can help you to get started.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

EXAIR Products in Construction Industry: Super Air Knife Helps Steel Door Drying

A manufacturer of both residential and commercial steel doors used in the construction industry recently contacted me for help with an application in their manufacturing process. They make a wide variety of exterior and interior doors as well as some custom doors that are sold to builders across the country.


The raw material for the doors is formed, assembled, and welded together before it is then taken to a finishing step that involves grinding down the welds and sanding any rough spots on the door down to a smooth finish. This smooth finish creates a clean look and also helps with the application of paint at the end of the process.

After finishing, the doors are hung on an overhead conveyor where they pass through a machine that cleans off all of the surfaces and remain hanging until they dry. This air drying prevented them from continuously operating as they’d have to wait at least 10 minutes until the doors dried before they could apply any paint. In the summer, humid conditions in their plant further increased the time the doors took to air dry.

Super Air Knife w/ Plumbing Kit Installed

Rather than waiting to dry, they wanted to blow off any remaining water from both sides of the door just after the washing operation. The solution was to install (2) Model 110048PKI Super Air Knives on either side of the door to blow off residual water as it moved along the conveyor. Since the spacing in between doors was 12’, they didn’t want to have to operate the knives continuously and waste unnecessary compressed air.

With the doors traveling slowly at about 30 ft/min and a significant space in between them, they also went with a Model 9064 Electronic Flow Controller to keep the air on only when necessary. A standard door height is just under 7′. At the speed they were traveling, it would take roughly 14 seconds for each door to pass through the flow of the knives while 24 seconds pass with no door.

With a minimum 10 minute dry time without the Super Air Knives, the overall drying time was reduced to 38 seconds. That’s a 93.6% improvement in the overall time of their drying process! By improving the drying process, they were able to increase their production to 100 doors per 8-hr shift.

(2) 48″ Super Air Knives operating continuously at 80 PSIG would require 278.4 SCFM of compressed air. The average cost of compressed air is $0.25/1000 SCF. So what did this cost when operating continuously with a 38 second blowoff time?

0.633 min x 278.4 SCFM = 176 SCF/door

176 SCF x 100 doors per shift = 17,600 SCF

17600 SCF x ($0.25/ 1000 SCF) = $4.40/ 8 hr shift

Over the course of a year that equates to $1,144 in operating costs. With the EFC implemented, the blowoff time was reduced to just 14 seconds per door.

0.233 min x 278.4 SCFM = 65 SCF/door

65 SCF x 100 doors per shift = 6500 SCF

6500 SCF x ($0.25/1000 SCF) = $1.63/ 8 hr shift

Not only were they able to increase their production rate by implementing the Super Air Knife, but by taking it one step further with the EFC they reduced the overall operating costs for a full year to just $423.80.


If you have a similar application in the construction industry and would like to speak to an Application Engineer please give us a call!

Tyler Daniel
EXAIR Corporation
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

Door photo courtesy of ErikaWittlieb via Pixabay

PVDF Super Air Knives Resist Chemical Exposure

When my sons were little boys, I would find myself looking forward to their teenage years, so they’d be more mature and I’d be able to relate to them better. Those of you with older kids may begin laughing now. My thinking was, I distinctly remember being thirteen. What I failed to recall was just exactly how peculiar I appeared to my parents (and they to me), and now, I’ve got the view from the other side.

In the interest of time and good taste, I’ll limit this discussion to the subject of food. I always liked (and still do like) ketchup almost as much as the french fries. Same for the “fixin’s” on a sandwich. In fact, as an adult, I’ve discovered a universal truth, that bacon or peanut butter can be used to improve the quality of ANY sandwich.

My sons, however, don’t feel this way at all. My fifteen year old won’t put anything but cheese (American cheese, at that) on a hamburger, and his thirteen year old brother won’t even do that. Curiously, the older one prefers cheese pizza, and the younger one will eat anything that used to be an animal on his. And neither one will put any sort of condiment or sauce on ANYTHING they eat. If it’s on their plate, it better not “have stuff on it.”

I was reminded of that phrase this morning during a conversation with a caller about an Air Knife application. It will be operated in the fairly aggressive chemical environment of a plating line. We discussed the chemical compatibilities of our different material offerings, and found that the Model 110006-PVDF 6” Super Air Knife was the one he was looking for. The body & cap are PVDF (Polyvinylidene Fluoride,) the shim is PTFE, and the fasteners are Hastelloy© C-276 alloy. It’s impervious to a long list of acids, caustics, and other harsh chemicals that even the higher grade stainless steels don’t stand a chance with.

PVDF Super Air Knives provide superior corrosion resistance.
PVDF Super Air Knives provide superior corrosion resistance.

Our PVDF Super Air Knives provide the same highly efficient and quiet performance as their aluminum, 303SS, and 316SS counterparts – plus you can get a lot more “stuff” on them without damaging them.

Regardless of where you need to install it, or what kind of stuff you might get on it, EXAIR has a Super Air Knife that will hold up in your application. Give us a call, and we’ll find the right one for you.

Russ Bowman
Application Engineer
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