On June 1, the U.S Environmental Protection Agency (EPA) announced the release of its draft Integrated Risk Information System (IRIS) health assessment for ammonia. The draft assessment was available for public comment for 60 days and will be sent for independent expert peer review.

Now that the Environmental Protection Agency (EPA) has approved the use of three hydrocarbon (HC) refrigerants in some smaller appliance applications, advocates of HCs are continuing to promote use in larger equipment, with commercial ice machines as well as reach-in/walk-in freezers and coolers possibly next in line.

When talk first surfaced a number of years ago about using R-744 (CO2) in commercial refrigeration, there were two challenges — making the refrigerant work as a stand-alone in transcritical applications as well as in cascade systems and developing the components to make such approaches possible. Where does the refrigerant stand currently?

The conversation on ways to make ammonia work in a wider range of refrigeration applications is drawing increasing attention these days. At the most recent International Institute of Ammonia Refrigeration (IIAR) conference in Milwaukee, technical presentations covered its uses in supermarkets, with heat pumps, in absorption refrigeration, and in conjunction with CO2.

The three functions of the condenser are desuperheating, condensation, and subcooling. Read to find out more about what the Professor has to say about these three topics. 

Manufacturers are increasingly designing their systems with unique controls and features that may apply only to their systems. Servicing, installing, and maintaining these new systems can be challenging. Sometimes they require us to reference material provided by the system or component manufacturer. Without this reference material, servicing, installing, or maintaining many of these new systems may be quite difficult or at times even impossible. What is a contractor to do? 

Whether we like it or not, R-22 is going away, and technicians need to look at their best options and solutions to work with the phaseout. One option available to all competent service technicians is to recover and recycle refrigerant.

In Europe, three recently completed construction projects all used ammonia as a refrigerant in some decidedly complex, yet energy-efficient projects. 

Noncondensable gases (NCGs), as the name implies, are not able to condense inside a condenser, unlike refrigerant gases. This can have a serious impact on system operating conditions, energy efficiency, and the lifetime of a system.

The upcoming games of the XXX Olympiad in London are featuring some of the latest state-of-the-art refrigeration and air conditioning equipment as well as the use of one of the oldest refrigerants, namely ammonia, as well as other natural refrigerants such as CO2 and HCs.