The first round of case study selections has been announced! BITZER, Danfoss & Colmac Coil Manufacturing, Embraco & Thermo Fisher Scientific, CTA Architects Engineers and Carter Synergy will present their innovative natural refrigerant case studies at ATMOsphere America 2015 in Atlanta, Georgia.

The ATMOsphere Review Panel has announced the first round of case study selections for ATMOsphere America 2015, which will take place on 25 & 26 June in Atlanta, Georgia. Additional case study selections will be announced over the coming weeks.

An “Industrommercial” CO₂ system by Joe Sanchez, BITZER US

As CO₂ continues to gain in popularity, many users are finding that the high volumetric capacity of this refrigerant (i.e. smaller compressors) is leading to some additional flexibility in the uses of the compressors. For example, the industrial world has been using larger open drive industrial sized compressors for subcritical CO₂. By using commercial sized compressors, they increase the part load efficiency; they employ semi-hermetic designs with less risk of shaft seal leakage and they decrease the effect of a down compressor. As, in many situations, ammonia is becoming a burden to apply in large quantities, expanding the usability of CO₂ ensures that a natural refrigerant is employed as opposed to using an HFC refrigerant.

The case study presents one of the largest industrial sites in the U.S. to employ this style of compressors. So far, the only other industrial application of semi-hermetic CO₂ compressors has been with ice rinks. If the customer has success with this concept, it could lead to many other applications employing a similar concept.

Ammonia DX low charge system proves sustainability by Terry Chapp, Danfoss and Bruce Nelson, Colmac Coil Manufacturing

The case study presents a project designed with a low temperature (below 0°F) direct expansion (DX) ammonia refrigeration system at Joliet Cold Storage Warehouse, a 130,000-square-foot warehouse and logistics center in Illinois. Opened in June 2014, the owner was looking for a cost-effective, sustainable refrigeration solution that would reduce construction costs and operate below OSHA’s 10,000 lb. PSM threshold.

The presentation will include a comparison of the two initial refrigeration design suggestions: a pump recirculated liquid (PRL) ammonia system and a DX ammonia system; and explain how the chosen DX solution was able to provide $100,000 in capital savings and use 35% less ammonia; thereby, allowing the owner to operate below the PSM threshold. It will also show how this solution is scalable for mainstream deployment.

US Defense Commissary Agency project, ammonia/CO₂ cascade refrigeration system, from design through completion by Rob Arthur, CTA Architects Engineers

CTA Architects Engineers, together with a project team including the Defense Commissary Agency, U.S. EPA Greenchill, Department of Energy, National Renewable Energy Lab and Hillphoenix, have designed and installed the U.S. Defense Commissary Agency’s first U.S. based ammonia/CO₂ refrigeration system in San Antonio, Texas.

The commercial refrigeration system is made up of 9 roof-top mounted primary ammonia water-cooled modules. These modules are grouped together and cascaded with a CO₂ combined DX/pumped refrigeration system mounted on a mezzanine internal of the store. Each module contains less than 10 lbs. of ammonia, meaning the total installation has an ammonia charge of less than 100 lbs. As the installation was in an established community, Hillphoenix created an ammonia system requiring the lowest possible charge, to address the public’s concerns about the total amount of ammonia that could leak into the air if a leak were to occur.

The idea behind implementing a modular type system was to achieve a level of flexibility for varying refrigeration needs. Regardless of the building type or size, the same refrigeration system can be used allowing for a level of repeatability from one project to another. The case study also looks at life cycle costs and cost comparison to those of a standard DX refrigeration system.

Integrated CO₂ convenience refrigeration installation by Paul Bevington, Carter Synergy

The purpose of this project was to bring CO₂ refrigeration to the BP estate and ensure that the maximum value and benefit in terms of environmental impact were achieved. As the key supplier, Carter Synergy designed and provided a fully integrated refrigeration solution, which provided all refrigeration capacity, a second temperature band for air conditioning and all building heat through heat recovery. Following the installation in 2014, a period of monitoring in direct comparison with a store of the same format in Cockfosters was initiated and continues to date.

The study has been carried out for 6 months so far and the store is demonstrating a 45% reduction in energy use for refrigeration and HVAC services, which ensures that the payback on investment will provide significant benefits to BP across the life cycle of the equipment. The period that has been monitored provides and excellent snapshot of a year as it contains months with high ambient temperatures and months with very low temperatures, leading to expectations that these savings will continue. The case study will look at how the project can be replicated in North America and present additional solutions for warm climate states.

About ATMOsphere America 2015
25 & 26 June at The Grand Hyatt Atlanta in Buckhead – Atlanta, Georgia

THE forum for HVAC&R industry experts to discuss the latest natural refrigerant market, technology and regulatory trends in North America returns for its 4^th edition. With a record 300-350 stakeholders expected to attend, the event promises better discussions and bigger results than ever before. Highlights include a series of parallel sessions featuring panel discussions and technology case study presentations for a variety of applications including light commercial, commercial & industrial refrigeration, heat pumps, HVAC and more.

Don't miss out, register today at www.ATMO.org/america2015/registration

For general information about the event, please visit www.ATMO.org/america2015