Air-Cooled Chillers for Las Vegas Revisited PDF

A little over a decade ago two articles appeared in ASHRAE Journal describing the analysis for retrofitting HVAC systems for 11 elementary schools in the Clark County School District (CCSD) in Las Vegas. Multizone systems using air-cooled R-22 chillers to replace rooftop units were proposed, and the articles raised concerns about efficiencies of using air-cooled systems in a hot and dry climate. Since the installation of these systems in the late 1990s, CCSD has collected 12 years of electrical use and maintenance cost data that show the air-cooled systems were the right choice for these schools. This article discusses the data and extrapolates the savings expected for the next 10 years.