Every successful project starts with a framework. A vision statement. A blueprint. The staff of Engineered Systems is proud to present The Blueprint — a monthly Q&A interview with HVACR engineering’s leading voices. These one-on-one discussions examine the trade’s history, current industry trends, the factors shaping the sector’s future, and more.

In this Blueprint Q&A, Michael Daly, chief technology officer, ECM Technologies, introduces readers to ThermaClear, examines the concept of oil fouling, explains how he’s found the HVACR industry’s fountain of youth, and much more.

Engineered Systems: For those of us in the engineering industry, it should come as no surprise that HVAC systems become less efficient over time. I know your company has done a great deal of research on this topic. Can you enlighten us on some of the information you've discovered?

Daly: You’re correct, HVAC systems experience a degradation of performance over time. For the most part, building occupants only care if they’re comfortable; they don’t care if the HVAC system is operating optimally. Very few of the causes for this degradation have been thoroughly researched. One are we focused on is called oil fouling, which is a slow degradation that, in essence, is robbing HVAC systems of their performance by impeding the heat transfer of those systems. All systems, other than those using oil-less, magnetic-bearing compressors, experience this. Oil fouling was first identified around 14 years ago. Design engineers have spent a lot of time optimizing systems to mitigate the effects of oil fouling, but it's really inherent in all designs.

Engineered Systems: How and why does oil fouling occur? Is it sort of like an automobile, where the oil sort of gums up and needs to be changed?

Daly: Oil in an automotive engine is an excellent example. Oil breaks down from excessive heat or contamination. And, in cars, we have the luxury of routine maintenance, allowing drivers to change their oil regularly. However, most HVAC compressors are hermetically sealed, thus you can’t change the oil. And, nobody would ever want to you to as you’d have to purge the refrigerant from the system, cut the compressor out, drain the oil out of it, and replace it. We just don't want to do that. So, the oil typically stays within the system for its entire lifecycle. Within that compressor, oil serves two purposes. First, it’s mean to reduce friction on the moving mechanical parts. Secondly, it acts as a seal for the gap between those mechanical parts. Just like in our automobile, there are oil rings in the compressor, on the pistons, and it's trying to keep enough oil to lubricate the cylinder. But, inevitably, it's there trying to keep it in the sump and crankcase. The reality is that, occasionally, some of the oil escapes.

Read the entire interview on Engineered Systems’ website.

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