Indoor climate in a winery - a holistic approach

Wine has been produced for thousands of years which makes it not at all surprising that everyone knows how sensitive the grape and the wine making process is to fluctuations in temperatures and changes in humidity levels. But, what about the modern wine production, indoors, in barrels? Our expert, Luca Zordan, Managing director Swegon Italy, will explain with an example at hand.

The origin of wine can be thought to be lost in the mists of time as researchers go back to identify the origins of viticulture. However, one thing seem to be certain, wine was invented before the wheel and with that it may be said that someone had a sense of priorities. Jokes aside. The area where the oldest finds have been found dates back 8.000 years and is located along the east shores of the Black Sea, where Europe and Asia meet. The Egyptians were the first masters of viticulture, grape wine and wine was then brought to Greece and from Greece to Italy. Thereafter, thanks to the Roman Empire, wine making was spread to the mid-south of Europe and further to present day.

Today it is reasonable to call an indoor space “a controlled environment” as it can be nearly completely separated from nature’s alterations. That is a good thing when it is stormy, pouring rain, extreme heat or other substantial weather impacts - the outdoor variations may be foreclosed. However, it puts firm requirements on the indoor climate. It needs to maintain a high standard over time and it needs to suit our needs as human beings as well as the demands of living plats, delicate fine art… and wine making processes.

The expansion of a winery

Vie di Romans is a family owned winery with long traditions. Located in the northeast of Italy, close to the Slovenian border, this area is well known for the production of white wines and has with certainty a long history of wine making as the soil is considered to be excellent for growing grapes.

The Vie di Romans winery produces mainly white wines, with a small production of red wines as well. The demand for their high-quality products had been growing for quite some time and increased the need for expansion. A decision to build new facilities on the existing ground was made in 2021. Not only was a new barricaya space needed for storage of wine barrels, but new office and hospitality buildings were also planned. Sustainability was, and still is, a very important factor for the family, led by Mr. Gianfranco Gallo. This was reflected both on the construction characteristics of the buildings and on the requests for the best suitable solutions for ventilation, heating and cooling in different indoor environments. At the end of 2023 the construction was completed.

Indoor climate considerations

Generally speaking, a controlled indoor climate is important in wine production, but in regards to the Vie di Romans winery and its barricaya, the control of thermo-hygrometric conditions and indoor air quality was critical. Although easier to define.

The importance lies in the fact that the alcoholic fermentation of the white wines - which is an exothermic procedure - is carried out directly in the wooden barrels stocked in the barricaya. This particular process gives the wine its unique characteristics, but the alcoholic fermentation and ethyl alcohol produces carbon dioxide (CO2), toxic to humans at a concentration of 2.5%, which is why the process requires meticulous control of the indoor climate conditions. Even at a concentration of 0.08% (800 ppm), a person’s performance, concentration and well-being is compromised.

Moreover, in addition to a persistent temperature of 15 degrees Celsius, all year round, the barrels need a relative humidity level of 80% to avoid oxidation of the wine and excessive evaporation through the porosity of the wood.

Obviously, the office and hospitality areas had completely different requirements, both different from the ”wine cellar” but also different from each other. People want to be productive in an office which requires a temperature around 21 degrees Celsius in winter and a little higher in the summer, while visitors in the hospitality area most likely are longing for a comfortable stay and can accept higher temperatures.

Fresh air in all facilities

As a first step, we supplied the barricaya with two air handling units (AHUs), type GOLD RX 040, with recirculation sections and CO2 sensors. It is completed with an external pressurised-water humidifier with direct misting in the room. These two units provide the needed air and moisture for the 2.500m2 barricaya where approximately 700 barriques, each of 228 litres, are stored.

For the office and hospitality buildings, another AHU of type GOLD RX 040 delivers fresh air through 20 WISE dampers which, in addition, control VOC, CO2 and humidity. A radiant floor provides heating in the winter and cooling in the summer, and each room is given post-heating coils which allow each visitor to adjust the thermo-hydrometric conditions based on their own demands.

Heating, cooling and monitoring

Now, in order for the wine to mature as planned the above air handlers were needed to be accompanied by units for heating and/or cooling as well as by a system for monitoring to make sure the set requirements were met meticulously and efficiently. The Gallo family had previous experience of other HVAC manufacturers and a solution where different components from different suppliers was on the table at this point. The consultant, installer and us at Swegon, then presented a way forward which took a holistic approach to the solution and suggested products and systems which facilitate the process, sustain quality and allow for both monitoring and control.

We ended up providing the winery’s barricaya with four reversible heat pumps units from our BlueBox range, model ZETA Sky HP 6.2. Correspondingly, two ZETA Sky HP 8.2 heat pumps were provided the office building and the hospitality area. Together they allow about 280kW of cooling capacity.

And to finish off, we installed a WISE system including a number of products which simplify control of the entire solution, minimize energy consumption and ease the service and maintenance procedures considerably. The system comes with the SuperWISE interface which gives a complete overview of how the system is performing during commissioning and daily operation. It allows for interaction and communication with single products and with the system as a whole. Moreover, SuperWISE allows for various notification schemes to be set, analysis of various parameters to be made and overviews to be shown in maps and lists. All in all, WISE supports a sustainable operation in terms of cost and time, indoor climate and environment.

From an application point of view, this was a very fascinating project, and the level of complexity with three different indoor climate requirements makes this a highly interesting and exciting journey. We got to know the Vie di Romans winery and Mr. Gallo over one and half years, and we are happy to know that they can focus on producing quality wines for many years to come. For more information, see our reference case of “Vie di Romans” here.