Sealing Cable Openings: How Grommet Choice Impacts the Bottom Line7 min read

by | Sep 9, 2015 | Blog

Today it’s no secret that unsealed cable cutouts in raised-floor data centers can cause a host of problems in the data center. What seems like a small detail can end up snowballing into bigger issues as the cooling and airflow management of the entire data center is thrown off kilter, creating wasteful bypass airflow. Issues can range from overheated IT equipment to millions of dollars in wasted cooling energy that never reaches the IT equipment.  Fortunately, by now most managers of raised-floor data centers understand the value of sealing cable cut-outs and turn to a variety of solutions, primarily brush grommets. But are all brush grommets created equal? And how does the choice of grommet impact savings over the long run?

A recent report published in ASHRAE®’s technical library examines these exact questions. The report contains the results of testing sealing effectiveness for 5 leading brands of brush grommets: KoldLok, CoolBalance, Air-Guard, Mink Bursten, and Air-Lokk.  The results showed a significant difference in the sealing capability of each brand.  Figure 2 below shows the sealing capability of each brand, on an area-corrected basis. The testing concluded that KoldLok sealed better than any other grommet by a clear margin.

Figure 1. Average area corrected leakage (in both SCFM/100 sq. in. and L s/100 sq. cm)4

The impact of this leakage turned out to be significant. When added up over a number of grommets over a number of years, the savings gap becomes large when comparing the brands. A 1 MW data center using KoldLok could save almost $1,000,000 dollars over a 10 year period. The next-best performing grommet, CoolBalance, offered savings of $648,000, while Air-Guard offered savings of $548,000—48% and  75% less than KoldLok, respectively.  Figure 3 below shows the full comparison.

Figure 2. Potential 10 year savings

While all grommets in the test offered some savings benefits, the fact that KoldLok offered 48% more savings than the next-best competitor illustrates how the choice in grommet can impact savings over the long run. KoldLok’s superior sealing capability—made possible by its dual-layer brush design—ultimately makes KoldLok the most economical grommet choice with its long-term savings capability.

Peter Matte, Vice President of Sealco, a national provider of data center cleaning and containment services, offered this insight: “The choice of grommet clearly has an impact on savings. That’s why we’ve only ever sold KoldLok. The ASHRAE®-published report only confirms what we’ve known all along—that quality wins out and saves you the most money in the long run.”

Upsite has made available a condensed version of the ASHRAE®-published report online. The full report is also available for download (for a fee) in the ASHRAE® technical library.

Lars Strong

Lars Strong

Senior Engineer


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