Like seeds carried by the wind, after the construction of the first “full scale” plant, our machines began to take root across the snows of Denmark, Sweden, and some in Italy. Between 2003 and 2004 about twenty plants were built. These were machines derived from the experience gained with the Treviso plant (see chapter 3). That is, machines with parallel compressors, single-stage for MV and two-stage internal compound for LT and with “open flash tank” type receiver.

Meanwhile other pioneers joined our journey: Linde Carrier completed a plant in Wettingen, Switzerland.  Although it was a relatively simple system (single stage for MT and cascade for LT), it was of significant size. It proved that we were on the right path as an industry leader followed what we had done. It was implicitly an acknowledgment.

The Wettingen plant bring some interesting steps forward: first of all the first Bitzer transcritical compressor, then the first electric valve – from industry – for controlling high pressure in gas cooler and the first gas cooler CO2-air from Luve.

It was clear at this point that, even if everything was still at “field test” stage, there were more players exploring the new technology, however still at an early stage.

In 2006, Danfoss handed us a surprising gift: the first high-pressure control valves. This allowed us to experiment with a daring new concept, the “economizer”.

The Economizer is a device designed to significantly improve the performance of the machine when the outside temperature rises. Under these conditions, the production of flash steam increases; through a two-stage lamination scheme and the extraction of steam by an auxiliary compressor.

By using a two-stage expansion and an auxiliary compressor to swallow this vapor, we pushed the machine’s efficiency into uncharted territories with the first real large-scale application in 2008, in Freiburg.

By 2007 and 2008, another profound milestone was reached: Supermarkets demanded a single centralized unit to manage both the MT fresh aisles and the deep-freezing LT rooms.

The result was the Booster system. Just around the same time of other industry players, we developed a design with integrated MT and LT, but considerably more efficient than a cascade system, since there was no intermediate exchanger, and the relative temperature difference and consequent thermodynamic loss, between LT and MV.

We also refined the use of machines with two-stage compressors, produced at the time exclusively by Dorin, the only ones on the market to believe in this technology back then.

Meanwhile in 2007 two new companies entered the market of CO2 “transcritical systems”. One of them was based in Denmark – Advansor – and the other in Sweden – Green&Cool; being a new small industry niche, I knew the founders well.

There were, in that period, several attempts to design large heat pumps for sanitary hot water, like what was happening in Japan after the success of small “Ecocute”. All that was important also for refrigeration, as Swep developed – for the promising market of heat pumps – a high-pressure water-cooled gas cooler which could withstand 120 bar, the model B16DW, which could be used as heat recovery heat exchanger in refrigeration units for retail. Moreover, Dorin compressors were improved, thanks to an extended test campaign which lasted several months, to bring at highest level their reliability.

Yet, skepticism still hung heavy over all over our heads and the market was paralyzed by the fear of 120-bar pressures. But in the mountains of Switzerland, Scandinavia and the UK and thanks to the foresight of partners like Frigo Consulting and Kaeltering, we found our foot installing several state-of-the-art systems.

In the shadow of the Alps, we were no longer just building machines; despite that the rest of the world still considered the technology “experimental”, we were forging a new philosophy of cold.