UPDATED:&nbsp;Sustainable Swiss supermarket new build includes CO2 refrigeration system

In spring 2011 the Prodega cash and carry in the Swiss town of St Blaise was reopened after a larger facility using sustainable construction solutions was built near the site of the old store. To reduce the environmental impact of the new building a CO₂ refrigeration system was installed, in addition to LED lighting. UPDATE: The St Blaise new build planned by Frigo-Consulting, uses an innovative waste heat recovery system combined with an ads

Originally opened in 2000 the Prodega cash and carry St Blaise had become in recent years too small to meet the needs of the local community. After a 14-month build a new store was opened only a few steps from the old structure. The centrepiece of the new building is the 750m² Cool-way, one of the largest refrigerators on the Neuchâtel lake.

With a surface area of 3000m², the cash and carry now stocks more than 30,000 items, catering to restaurateurs, hoteliers, and the general public.

R744 refrigeration systems selected for new store

At the heart of the plans for the St Blaise construction were environmental considerations. For example, to ensure the refrigeration system met the strict sustainability criteria for the new build, a natural refrigerant CO₂ system was selected. To save energy, LED lighting was incorporated.

The St Blaise build follows other Prodega/ growa cash and carry renovation projects with CO₂ installations, including Basel, St-Gall and Quartino stores.

Overall, the new St Blaise building was designed in accordance with the Swiss MINERGIE standard, a widely accepted trademark for new and refurbished buildings supported by the Swiss Confederation, the Swiss Cantons and the Principality of Liechtenstein. To receive the MINERGIE standard proof of energy performance of the building heating, hot water, ventilation and air conditioning systems must be supplied.

Increased CO2 refrigeration capacity thanks to waste heat recovery system

Planned by Swiss engineering company Frigo-Consulting, the refrigeration installation in the St Blaise cash and carry uses a pioneering adsorption chiller that enables waste heat from the transcritical CO2 system to be converted into energy for cooling.

Transcritical CO2 installations can produce considerable amounts of heat. The new Frigo-Consulting technology allows for this waste heat to be used in an adsorption chiller, which in turn allows for an increase in the capacity of the CO2 refrigeration system.

Swiss CO2 installations

In November 2004 the first CO₂ direct expansion refrigeration system was installed in a Swiss hypermarket in Wettingen. The multi-compressor R744 refrigeration system resulted in a lower energy consumption than R404A for out door air temperatures below 28°C.

Since then several supermarket chains have made the switch to CO₂ refrigeration systems. For instance as part it its greenhouse gas (GHG) emission reduction strategy, the retail chain Coop has selected R744 as the refrigerant of choice for new and refurbished stores. In explaining its choice Coop refers to the energy savings that can be achieved using CO₂ systems, in addition to the zero ozone depleting potential (ODP) and low global warming potential (GWP) of R744.

Migros have also turned to CO₂ to meet their refrigerant needs, in addition to ensuring that all new and refurbished buildings meet the MINERGIE standard.

Background

Since July 2003 HFCs have been tightly regulated in Switzerland, making alternative refrigerants such as CO₂ attractive cooling solutions. The HFC regulation encompasses licensing, reporting, leak checks, servicing and end-of-life requirements for equipment containing more than 3kg of such refrigerants.