A lot of talk these days about natural refrigerants focuses on CO2, propane, isobutene, and the like. Stateside, they may be new kids on the block in terms of HVACR applications. But one natural refrigerant that has been around seemingly forever is ammonia. So it - like those “newcomers” - is drawing a lot of attention.
Actually, frost on the suction line only indicates that at the location where the frost is present, the suction line piping is below the dew point temperature of the surrounding ambient air and at or below 32°F. That’s it. It is neither an indication of a properly operating system nor a system defect.
In response to environmental concerns raised by the use of high global warming potential (GWP) refrigerants, the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) is launching an industry-wide cooperative research program to identify and evaluate promising alternative refrigerants for major product categories.
Eurammon - a joint European initiative of companies, individuals, and institutions who advocate natural refrigerants - is calling for entries for the Natural Refrigeration Award which will be presented to the best scientific dissertation in the field of natural refrigerants.
At the Euroshop 2011 Expo in Dusseldorf, Germany, in March, Carrier Corp. introduced what it called “the latest innovations in CO2 and hydrocarbon refrigerant solutions, turnkey and heat recovery systems, and after-sales support and services for the food retail business.”
While CO2 is being successfully used in subcritical applications in the United States, it is more of a challenge in transcritical situations because of demanding compressor technology and high pressures. The UK office of Sanyo Air Conditioners recently issued two case histories showing the refrigerant being used for heat pumps in commercial applications.
Issues that could some day affect the way HVACR contractors do business continue to draw attention in both Europe and Asia. Nothing being talked about right now has any direct impact on the North American market, but the issues remain on the industry’s radar screen for what possibly could happen in the future.
While polyvinylether (PVE) oil first started to be used by OEMs in 2010, it continues to draw interest, especially as a possible alternative to polyolester (POE) oils with HFC refrigerants. “So far in the States, we have two manufacturers using PVE extensively,” said Eric Schweim of Idemitsu Lubricants America Corp.
The year 2010 and the start of 2011 has proved to be an interesting time for Midwest Refrigerants, a company that approaches the elimination of unwanted refrigerants from a different direction. Midwest has developed a process that breaks down refrigerants to “their original chemical constituents,” as noted by ACR News, a British journal, in a January 2011 report.
It has been more than two decades since the first refrigerant recovery unit came to the HVACR market and became part of the tool arsenal for service technicians. Over that time, two things have become clear: Even a repairable unit doesn’t last forever and the newest units are able to do far more than their predecessors.