In this issue of Process Cooling, we have several articles that look at different ways to improve the cooling efficiency of refrigeration systems.

Industrial refrigeration contractor Gartner Refrigeration was tasked with lowering a Minnesota dairy plant’s energy consumption. Gartner realized that use waste heat from the compressor oil coolers could be used heat water at the plant, but the water demand was sporadic. Could one system be designed to produce hot water as needed and cool the compressors? It could, and in “Valve System Reduces Energy Consumption of Refrigeration System,” Jason Paquette and Terry Chapp of Baltimore-based Danfoss Refrigeration & Air Conditioning describe how a liquid-injection oil cooling system delivered for the dairy.

When selecting a refrigerant, prospective users must evaluate factors such as system capacity, plant location, system design and compatibility, and regulatory requirements. So says Chris Kapsha and Craig Thomas of Devault Refrigeration, Colmar, Pa., in “Refrigerant Selection for Industrial Refrigeration.” The authors note that a poor refrigerant selection can impact facility operating costs, increase regulatory compliance requirements and increase maintenance and installation costs. It’s a decision you will live with for the life of the system, so it is one to spend some time evaluating the options.

Where aging air-cooled condensers and air-conditioning equipment cannot meet the cooling demand, an old technology improved — evaporative fogging — can provide cooler-than-ambient air to increase performance and enhance cooling. As Mike Lemche of MicroCool, Thousand Palms, Calif., explains in “Evaporative Fog Saves Aging Refrigeration Equipment,” evaporative fogging is not a new technology, but it is one that had fallen out of favor. In the past, simple water sprinklers and some water mist systems were used to reduce condenser coil surface temperatures. The approach was abandoned when coil contamination by calcium and magnesium carbonate reduced thermal transmission. With the advent of new nozzle designs and the addition of reverse osmosis is enjoying a renaissance and is finally able to effectively extend the life of air-cooled equipment.

Water cooling isn’t only finding new use for air-cooling industrial refrigeration equipment, and we also have two articles related to evaporative cooling. In “Advanced Chlorine Technology for Cooling Towers,” Justin Shim of Justeq LLC, Northbrook, Ill., describes how a single-feed, ready-to-use liquid biocide for industrial water treatment applications — a stabilized chlorine-based product — penetrates into slime masses and produces bromine in situ to break up slime masses from within. Shim looks at removal efficiency, biocide consumption rate, the potential for metal corrosion, compatibility with water treatment chemicals, pH effect and ammonia-contaminated conditions.

Linda Becker, Associate Publisher and Editor,