UPDATE: AHR Expo Exhibitors Bullish on CO₂ in America

 

One of the well-known concerns about transcritical CO₂ refrigeration systems is that they work less efficiently in warmer climates. At the AHR Expo, Baltimore Aircoil addressed that concern with a new version of its TrilliumSeries Condenser for transcritical CO₂ applications, which has been installed at a few U.S. supermarkets. The condenser’s adiabatic design makes it possible to “eliminate restrictions due to warmer climates and save additional energy in cooler ones,” according to the company. 

 

The system operates as a condenser in subcritical mode when the ambient temperature is below 87.8°F (31°C) (the critical point of CO₂), and as a gas cooler in transcritical mode when the temperature is above that temperature. It minimises water use and saves 46% more energy than an air-cooled condensing system, said Candice Nager, senior marketing communications coordinator for Baltimore Aircoil.

 

Another solution for warm ambient temperatures was an adiabatic cooling system from Güntner, which works as a dry cooler or condenser in a CO₂ transcritical system. It uses evaporative pre-cooler pads only on peak temperature days, which improves system efficiency, said Glenn Comisac, vice president, industrial cooling business, Güntner U.S. This results in 60% to 90% water savings compared with conventional evaporative systems, according to Güntner. The company also offers a dry cooler for CO2 transcritical systems used in northern climates.

 

Güntner’s cooling systems for CO₂ are used in European supermarkets and are beginning to be employed in North American stores as well, said Comisac, who believes CO₂ systems have a future in the U.S. “Other companies [at the AHR Expo} are playing up the CO₂ angle. It’s a coming trend and we want to be a part of it.”

 

 

SWEP has a new brazed plate heat exchanger, B18SC-U, which can be used in transcritical CO₂ systems. The unit has 0.6 mm plates and requires no frame, which “makes it more cost effective” as well as eco-friendly, said Derek MacKinnon, regional sales manager for SWEP, at the company’s AHR Expo booth. 

 

OEMs using the heat exchanger are expecting more installations of CO₂ transcritical systems because of impending HFC regulations, noted Utpal Naik, business engineer for SWEP, adding, “The idea now is to reduce your global carbon footprint.”

 

Another brazed plate heat exchanger manufacturer, Kaori, displayed its latest C series product, CO₂, a downsized unit suitable for a CO₂ heat pump. The C series heat exchangers operate up to 140 bar and exhibit “high durability for R744,” according to the company.
 

 

Mueller displayed a set of copper tubes, valves and fittings for conveying CO₂ to cases in transcritical supermarket systems. 

 

 

High-pressure copper-alloy tubing from Wieland, and fittings from Conex Banninger were also on display at the latter’s booth under the K65 brand. The tubing consists of 2% iron, which allows it to handle pressures up to 1,740 PSI (120 bar), said Andreas Hinkler, group OEM sales director. Because of the high strength of the material, the tubing can be made with “comparatively thin walls,” saving material and making handling easier, said a company brochure.

 

The tubing is suitable for a transcritical CO₂ commercial refrigeration system for supermarkets. It has been employed in European supermarkets, but not yet in North America. 

 

“We are talking to OEMs and gave samples to companies here,” said Hinkler. “We think the market in the U.S. is really big and will increase in the next years.”

 

 

On display at the Dorin Compressor/Blissfield Manufacturing booth was a new steel CO₂ condenser/gas cooler, certified for “2,200 PSI (151 bar) design and 6,600 PSI (445 bar) ultimate strength.” 

 

Blissfield, which has been making steel products since the 1960s, was well positioned to produce a condenser that could “withstand high pressures,” said Brandon Farver, marketing/technical support for Blissfield. The UL-approved condenser uses a continuous tube and promises to be leak free and low maintenance. 

 

OEMs and bottlers are incorporating the Blissfield condenser into transcritical CO₂ systems that serve small beverage cabinets.

 

Blissfield was also displaying a spiral fin steel condenser/gas cooler imported from China. It features “small tube diameters ideal for CO₂ and propane,” said a Blissfield brochure.