For 30 years, the HVACR industry has been in a “what’s next?” mode when it comes to refrigerants. However, there may be no more “nexts.” Moving forward, what you see is what you get.
Recognizing four generations of refrigerants, engineering consultant James Calm said, chemicals, such as SO2, ammonia, hydrocarbons (HCs), and CO2 (the latter being rediscovered these days), fit the whatever-works phase three decades ago. But, such issues as toxicity and flammability brought about the second generation of gases, that of chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). When the ozone depletion issue arose, the industry produced a third generation of refrigerants: hydrofluorocarbons (HFCs). Then, global warming concerns brought about the current fourth generation of refrigerants involving low-global warming potential HFCs, hydrofluoroolefins (HFOs), and the so-called naturals (including a revisit to CO2 and HCs).
But now comes a significant statement from Mark McLinden of the Applied Chemicals and Materials Division of the National Institute of Standards and Technology (NIST). In speaking to an audience of engineers and researchers from throughout the world this July at Purdue University, he noted that ongoing research is the end of the line, and that analysts are bumping up against the physical limits of chemistry. When asked if there will be a fifth generation of refrigerants, he responded, very matter of factly: no.
It should be noted at this point that the final generation of refrigerants still has to sort itself out. But, by my count, there are about 60 refrigerants considered low-GWP HFCs, HFOs, or naturals currently being studied and tested to create cooling and refrigeration. Many are already in the field being used. That number has to work its way down to a more manageable figure, given the limit as to how many canisters can fit in service vans. But, it won’t be one or two. It could be dozens. The point Dr. McLinden is making is that what is currently being worked on is all there is or will be.
He did note there are other ways to create refrigeration beyond use of refrigerants such as low-pressure vapor, thermoelectric solid state, and absorption cycles. But he noted this is beyond the current research being done by NIST and most of the maunfacturers and academia who are involved in HVACR.
For contractors, the point is that what emerges from this research will be what they’ll be working with for many years to come.
A further point is that it appears the days of shellshock are over. I came into the industry when CFCs were about it, with some use of HCFCs. The forced phase out of CFCs caused a move to HCFCs, which was not all that smooth on the refrigeration side. Then came those new-fangled HFCs, which many were initially scared about because of higher pressures and the use of non-mineral oils. Adjustment along the way was done with much grumbling and complaining, along with shortfalls of chemicals causing price spikes and a learning curve for technicians, to say the least.
But, the good news is that low-GWP HFCs are still HFCs, and we’ve been working with HFCs for years. HFOs are being used in automotive applications and, after all, that sector was using HFCs before the stationary sector, thus the transport folks can help us deal with HFOs. And plenty of manufacturers are currently working with CO2 and HCs in refrigeration applications.
So, hold on Mr. and Ms. Contractor — the long, winding, bumpy, and nerve-wracking refrigerant road may smooth out soon. Now, if you can only figure out a way to get your customers to pay promptly.
Publication date: 9/1/2014