A technician from a company that performs comprehensive audits of compressed air systems called me with a sad, sad story. A client had just installed a brand-new state-of-the-art rotary scroll compressor with a variable speed drive…they were going all-out on efficiency, which is great. During the technician’s walk-through, however, he noticed a blowoff on a conveyor belt — they actually heard it before they could see it — a black iron pipe with a series of holes drilled along the length, plumbed with compressed air being supplied, unregulated, from a 100psig header.
The pipe was 18″ long and had 30 holes, 1/8″ diameter each, drilled along the length. From the table below, we can presume that this drilled pipe was consuming as much as 475.8 SCFM:
The technician first asked about installing Air Nozzles in the drilled pipe. That’d mean drilling those holes out and tapping them individually. This COULD be done, and the drilled pipe could be fitted with 30 Model 1110-PEEK Nano Super Air Nozzles, with an air consumption of 8.3 SCFM @80psig each, for a total of 249 SCFM. That’s a significant reduction, but also a lot of work on the drilled pipe. I recommended replacing it entirely with a Super Air Knife.
A Model 110018 18″ Aluminum Super Air Knife consumes only 52.2 SCFM @80psig — almost an order of magnitude reduction! Let’s do the math on the costs:
First, the drilled pipe: Let’s give all the benefit of the doubt here and assume that the line loss had indeed limited the air consumption to 350 SCFM. Operating 8 hours a day, 5 days a week, 52 weeks a year, and using the US Department of Energy’s estimate that compressed air costs $0.25 per 1,000 Standard Cubic Feet used, the annual operating cost of the drilled pipe was $10,920.00:
350 SCFM X 60 min/hr X 8 hrs/day X 5 days/week X 52 weeks/year X $0.25/1,000 SCF = $10,920.00
Drilling & tapping those holes for EXAIR Nano Super Air Nozzles (8.3 SCFM ea X 30 = 249 SCFM total) would result in an annual operating cost of $7,768.80:
249 SCFM X 60 min/hr X 8 hrs/day X 5 days/week X 52 weeks/year X $0.25/1,000 SCF = $7,768.80
Replacing the drilled pipe with an EXAIR 18″ Super Air Knife (52.2 SCFM) drops the annual operating cost even further, to $1,628.64:
52.2 SCFM X 60 min/hr X 8 hrs/day X 5 days/week X 52 weeks/year X $0.25/1,000 SCF = $1,628.64
To put that further into perspective, the 2025 List Price for an 18″ Aluminum Super Air Knife is $533.00. It costs almost $9,300.00 per year LESS to operate than the drilled pipe. That means the Air Knife will have paid for itself in operating costs in just under 21 days.
To put that even FURTHER into perspective, the ~300 SCFM reduction in compressed air consumption is approximately 75HP worth of a typical industrial air compressor load. It’s not uncommon for a mid-to-large sized company to have more than one air compressor, and 50HP is a common size for a backup compressor. If that was the case in the facility that my technician caller was auditing, he’d be letting them know that this $533.00 investment that’s going to save them over $9,000.00 a year is ALSO going to allow them to shut down one of their air compressors. Completely.
So, THAT’S what’s so awful about a drilled pipe. If you have any in your facility, we should talk.
Russ Bowman, CCASS
Application Engineer
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