Environmental Update - Latest on Refrigerants
Posted on Tue, Apr 05, 2011
By Larry Butz - GEA Consulting
For those who have not seen our quarterly newsletter I invite you to check out the last issue as well as past issues for news and information relevant to the Global HVAC industry on these topics:
- Global Warming/Climate Change
- Ozone Depletion
- Refrigerants
- Global Water Shortage
- Clean Energies
- Green Buildings
In this most recent issue I provided the following commentary of the new phase we are entering with a whole new cast of characters.
Just when we were getting used to R-404A, 134a, 410A and a few others we decide that that's just too simple. First we get the new HFOs-1234yf and 1234ze that have lower GWPs to meet European carmakers needs to replace R-134a. This seems to have reactivated the "dial-a-blend" concept from the late 1980's from which blends such as R-410A , 404A and 407C emerged.
Today's staggering array of alternatives were partially exposed at the recent ASHRAE Winter Conference with code names such as DR-4 and DR-5 or N-40, l-20 or L-YF, each being a customized combination to yield a specific GWP in a particular application. Obviously all other characteristics vary as compositions change. Capacity, efficiency, flammability, toxicity, high ambient performance, cost, etc all vary as well as our need to remember what the differences are between azeotropic and zeotropic mixtures and how that impacts sytem design, servicing and handling requirements.
With "dial-a-blend" we just optimize for each unique application, part of the world, technology type, etc. The race is on to determine winners and losers in the latest version of refrigerant wars. It should be interesting.