The ATMOsphere Review Board has announced the second round of case studies selected for presentation at the 4th annual ATMOsphere America in Atlanta. Congratulations to Hillphoenix, CIMCO Refrigeration, Sanden, Microgroove, DC Engineering & Whole Foods.The following natural refrigerant based case studies have been selected 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.
Case study with a national retailer – comparing calculated energy consumption and actual energy results of a CO2 booster system by Jeff Newel, Hillphoenix
At the previous ATMOsphere America in June 2014, Hillphoenix presented the theoretical energy consumption of a CO2 booster system with an adiabatic gas cooler which was being installed at a Sprouts Farmers Market store in Dunwoody, GA. The case study explored the differences in energy consumption between that system and the standard DX 407a system typically installed in Sprouts stores.
This 2015 case study will draw comparisons between what was theoretically predicted for energy consumption at the store and what has been measured during operation. It will also discuss the practical side of doing in-store energy studies and the obstacles in the operation of any type of refrigeration system installed at a supermarket that need to be understood and overcome before anything can be inferred.
New development in natural refrigerant equipment by Benoit Rodier, CIMCO Refrigeration
The case study will discuss a new technology using ammonia and CO2 that is available on the market. The system is a self-contained package equipment for low temperature freezing applications. It consists of a newly designed semi hermetic ammonia screw compressor running at a low suction temperature to cool down a CO2 brine loop. A shell and plate cascade cooler is used as the evaporator as well as the condenser, significantly reducing the ammonia charge of the package. The CO2 is recirculated via a hermetic pump located under the CO2 receiver vessel.
On the heat rejection side, the condenser rejects heat in a glycol loop connected to an outside fluid cooler. The oil cooling system also rejects into the same glycol loop. This warm loop can be used for the heating requirement of the facility, for example under slab heating, dock space heating, fresh air intake pre heat, etc.
The overall system performance is improved through the use of a very low delta approach on the heat exchanger and through the use of two economizer ports on an integrated two stage semi hermetic screw compressor. This technology has largely been used in Japan with measured results exceeding the performance of single and two stage ammonia systems. This equipment is now available in North America.
Residential CO2 heat pump water heaters cold climate field testing by John Miles, Sanden International USA
Sanden is currently collaborating with a consortium of utilities, government and university resources to conduct three different field tests across multiple sites in the North West US. These field tests are designed to assist in determining performance, efficiency, integration and product life cycle costs for a split type CO2 heat pump water heater product when used in multiple applications in a cold climate geographic area, including the use of the unit to provide both domestic hot water and space heating for a home. The Sanden split type CO2 units used are based on the Eco Cute water heater products currently sold in Japan with specific modifications for the North American Market.
The case study presentation details both results, including energy monitoring and analysis together with observations in regard to the split type CO2 based heat pump water heater installation and operation during the three field test. The results provide tangible data showing that a split type CO2 heat pump water heater offers significant sustainable efficiency improvements over existing North American water heater products. The presentation will also discuss some of the challenges facing the CO2 heat pump water heater, especially in a split product, where the CO2 heat pump is separate from the water tank.
New copper-tube technologies for CO2 heat exchangers by Yoram Shabtay, Heat Transfer Technologies, Jian Yu, Super Radiator Coils and Nigel Cotton, International Copper Association
Copper tubing is used in R744 gas coolers and evaporators in applications ranging in size from small refrigeration systems for vending machines to large industrial cooling systems. Comparing various diameters of copper tubes with the same wall thicknesses, burst pressures are much higher for the smaller diameter tubes. Copper tubes up to ten feet in length with wall thicknesses of 0.040 inches (about one millimeter) have been hydraulically expanded to obtain a mechanical fit against aluminum fins with 10 fins per inch.
This presentation will describe the performance of such gas coolers and evaporators currently produced in North America for real-world commercial and industrial applications and will discuss the practicality of manufacturing such systems in volume. It will also present new high-strength tube alloys and research on new copper tube technologies.
A case study of the CO2 systems in Whole Foods Market Northern California region by Tom Wolgamot, DC Engineering and Tristam Coffin, Whole Foods Market
This case study examines the various applications of CO2 systems within the Whole Foods Market Northern California Region. It will update the case study presented last year at ATMOsphere America 2014 with additional energy consumption data, as the stores reviewed then have now been operating for a full year. In addition, two more CO2 stores were brought on-line and yet another facility is under construction. Preliminary energy data from these newest facilities will also be reviewed.
The facility under construction utilises ammonia as a primary refrigerant. System schematics will be reviewed, as well as Whole Foods Market’s overall expectations for these sustainable facilities. A summary of how these projects are meeting those expectations will be provided. The presentation will also discuss lessons learned so that others may successfully leverage those items into their facilities.
About ATMOsphere America 2015
25 & 26 June at The Grand Hyatt Atlanta in Buckhead – Atlanta, Georgia
Once again, ATMOsphere America 2015 will serve as THE forum for HVAC&R industry stakeholders to come together to discuss the latest natural refrigerant market trends, technology innovations and regulatory issues. The 4th annual event in Atlanta, Georgia will have more participants and better discussions than ever before. Additional highlights include optional site visits and training sessions on the days before and after the conference.
Reserve your spot, register today at www.ATMO.org/america2015/registration
For general information about the event, please visit www.ATMO.org/america2015