ASHRAE Journal - February 2009 - 5

C O M M E N TA RY With the planned phasing out of R-22, CO2 is getting a new look as a refrigerant for supermarket refrigeration, and it looks quite good. One reason is that CO 2 has lower global warming impact and ozone depletion potential than HCFC and HFC refrigerants. It also is nonflammable and less toxic than other natural refrigerants. Further, CO2 is inexpensive, widely available, not subject to venting requirements, and requires smaller and lighter equipment, which lowers installation costs. But CO2 also has design challenges, most notably from higher operating pressures and Fred Turner low critical temperatures, and it has been slow to catch on in North America. This means that parts for the systems are not always readily available, as are contractors who can install and maintain these systems. AN ARTICLE in this edition by David Hinde, Member ASHRAE, covers experiences with CO2 systems in North American supermarkets. There are at least eight of these systems in operation in the U.S. and Canada. All are using CO2 as a low-temperature, two-phase secondary fluid. The stores range from small markets to large, warehouse-type stores. Hinde’s article covers the major issues that were encountered during installation and operation of these systems and system performance. It is one of three articles in this issue on retail refrigeration. Still ruled by first cost and energy consumption, this sector is trending toward technologies with lower refrigerant charge and lower leak rates because of the growing awareness of CO2 Getting a New Look The Journal Is Celebrating 50th Year ASHRAE Journal is celebrating its 50th Anniversary this year, and we’re celebrating by republishing some of the more important Journal articles that have been printed over the years. Full versions of these articles exist mainly in a few libraries, as they predate electronic storage. The first of these articles is “Air Handling Unit Design for Energy Conservation” from the June 1977 issue. The author is the late Arthur E. Wheeler, P Fellow ASHRAE, .E., a pioneer in the field of indoor air quality. The article tests an “ancient” rule of thumb for choosing the face velocity when selecting central air-handling units for air conditioning. These special articles will continue each month until March 2010. If you know of an article that should be republished, please let us know. THE JOURNAL is a by-product of the merger in 1959 of the American Society of Refrigerating Engineers (ASRE) and American Society of Air-Conditioning Engineers (ASHAE) and their publications. ASRE published Refrigerating Engineering, and ASHAE published ASHAE Journal. While four-page versions of ASHRAE Journal were published in January and February 1959, the first issue of ASHRAE Journal as a magazine was published in March 1959. We’ll have more on the anniversary as the year progresses. the environmental impact of greenhouse gases and possible new government regulations. This makes CO2 and this article especially important. A SHRAE ® Journal | 1791 Tullie Circle NE | Atlanta, GA 30329-2305 | Phone: 404-636-8400 | Fax: 404-321-5478 | A SHRAE Online: www.ashrae.org Publisher W. Stephen Comstock Editor Fred Turner | fturner@ashrae.org Managing Editor Sarah Foster | sfoster@ashrae.org Associate Editors Rebecca Matyasovski | rmatyasovski@ashrae.org Charlotte Tubbs | ctubbs@ashrae.org Christopher Weems | cweems@ashrae.org Copy Editor Jeri Eader | jeader@ashrae.org Publishing Services Manager David Soltis Production Jayne Jackson Tracy Becker Advertising Sales Manager Greg Martin | gmartin@ashrae.org Advertising Production Coordinator Vanessa Johnson | vjohnson@ashrae.org Circulation Specialist David Soltis | dsoltis@ashrae.org ASHRAE OFFICERS President William A. Harrison President-Elect Gordon V.R. Holness, P .E. Treasurer Lynn G. Bellenger, P .E. Vice Presidents Jim Fields Andrew Persily, Ph.D. Vincent Tse Thomas Watson, P .E. Secretary & Executive Vice President Jeff H. Littleton POLICY GROUP 2008 – 09 Chair Publications Committee Julia A. Keen, P .E. Washington Office washdc@ashrae.org Member of the Audit Bureau of Circulation February 2009 ASHRAE Journal 5

ASHRAE Journal - February 2009

Table of Contents for the Digital Edition of ASHRAE Journal - February 2009