Nave de Vero sails to sustainability

A total volume of 500,000 cubic meters, 55,000 square meters of retail space, including a 4,000 square meter hypermarket and galleries of over 15,000 square meters; 120 commercial units and wide range of dining areas, offices, 2,400 parking spaces of which 1,200 of them are covered. These are just some of the impressive numbers related to the new shopping centre that has just opened in Marghera, Venice: “Nave de Vero”.

The overall design, created by London-based architecture firm Design International, is original and has a strong effect: the building looks like a big ship from which a vessel of glass and steel emerges from the side – hence the name of the complex, which hosts the main entrance and consists of full height glass facades externally enclosed by a steel structure. The building is overlooked by large sails made ​​of photovoltaic panels.

Design International is responsible for the final master plan, architecture, landscape design, lighting design and interior design, working closely with Milanese-Modena, the local architects on the project.

Davide Padoa, principal architect and CEO of Design International says:

“We have created symbolic elements that express the individuality of each and every shop and restaurant in a vibrant meeting place. I am glad that our client trusted our design vision and our playful style to enhance volumes, light and the individuality that we expressed for each shop and restaurant.”

In the design of the interior space is characterised by curved lines, organic and neutral colours (white, grey and sand) that give different signs of the highest quality with great strength and personality. The commercial offer is enhanced by an architectural concept characterised by transparency and natural light.

Gino Antonacci Chief Operating Officer of Corio Group, said:

“We have worked extensively with the designers and the managers of different brands to let them study the display methods of the new generation. We asked for transparent and coloured window fittings that could integrate harmoniously in the context of the centre, creating a wide-ranging pleasant perception, but at the same time a strongly characterised and unique presence”.

The executive project, the construction management, the coordination and site safety management have been taken care of by Tecnostudio, based in Padua.

The project has been ambitious both in the attention to finishing details, as well as in the choice of materials and the plant equipment.

The new shopping centre is indeed the very first mall in Italy to obtain the Breeam – Interim Certificate (BRE Environmental Assessment Method / Europe Commercial 2009 – Retail, intermediate certificate on the project. This certification process will lead, within the year, to obtaining a final certification with an expected level of VERY GOOD).

It is one of the most demanding international protocols for environmental assessment, which sets the standard for high quality green buildings. It represents the parameter used as a reference for assessing the building’s environmental performance in design, construction and use.

The BREEAM certification was strongly recommended by Corio, a real estate company that develops and manages shopping malls with high quality standards all over Europe, able to attract the best brands and thus maintaining a large consumer base. The Corio’s Italian portfolio presently consists of 10 shopping centres with a total retail area of approximately 400,000 m² and a value of approximately € 1.5 billion euro.

Many design choices have been made ​​to guarantee environmental sustainability such as the mechanical ventilation with heat recovery, the construction of a rainwater collection tank that will be used for the irrigation of green outside areas, a photovoltaic plant and a photocatalytic permeable floor to reduce pollutants in the air. All the above solutions have been employed to ensure the building’s high energy performances and give an A+ energy rating to the mall.

The design and the realisation of the HVAC plant, which in modern buildings accounts for about 50% of energy consumption and CO2 emissions was part of the certification strategy.

The Manens-Tifs’ project represents a solution that has the capability to achieve the compromise between the best energy performance and reduced water consumption.

The hypermarket and the shopping mall have separate and independent facilities. The first one consists of a heating plant with condensing boilers, air-cooled chillers and air handling units and the second one is composed of a plant room with high efficiency chillers.

Going into details of the shopping centre’s HVAC plant, it is based on 3 air cooled units with reversible heat pumps, FOCS-N/ SL-CA4822 by Climaveneta, and 3 chilled water tower chillers, FOCS2-W/ CA by Climaveneta.

Each chiller is sized to compensate, in the case that one of them fails, up to 80% of the maximum project load.

The system also provides 4 condensing boilers, fuelled by natural gas, that can provide 100% of the winter heat loads, and have been designed as a full backup to the heat pumps.

The plant sequence operation has been designed to maximise the efficiency in every season and with any kind of load.

During the mid-season (about 20-25° outside) air cooled units’ efficiency is high and so it is better to let them work; in case of heating request, it is always possible to use a unit in heat recovery mode.

When the outside temperature increases, since the efficiency of the air cooled units decreases, it is better to use the more efficient water cooled heat pumps. Only in mid-summer, with high external temperatures, will the air cooled units run again.

Moreover, since some users may also request hot water during the summer, the two types of units have been equipped with partial heat recovery (four out of six units).

In winter, to maximise the building’s energy efficiency, the units operate in free-cooling mode to ensure the best comfort in the galleries.

On the contrary, when cooling the shops in the winter, which cannot rely on free-cooling, it is necessary to operate a unit giving priority to the air cooled units which are more efficient at low temperatures. With an external temperature of 5°C the power required for heating is covered by only two units operating in heat pump mode, leaving the third one free to work as a chiller. Condensing boilers only work with extremely cold temperatures when heat pumps are not energetically convenient; the operation of boilers and heat pumps is never simultaneous.

Finally, given the low loads compared to the power involved for serving the entire mall and given the possible simultaneous request of cold and hot water, Manens-Tifs decided to equip the offices with an independent multi-purpose unit serving a 4-pipe HVAC plant, able to produce cooling and heating at the same time.

The considerations that led to this configuration were laid down by the desire to simplify the plant room with only two main types of units, simplifying the HVAC plant management and maintenance.

The presence of water tower cooled units, more efficient with respect to air cooled versions, and the possibility to heat by using only heat pumps, even with low temperatures, conveys strengths to the BREEAM certification purpose.

Particular attention has also been given to the air distribution in the upper level of the shopping centre, achieved by high induction nozzle diffusers, with different launch features through the introduction of swirl effect elements, depending on the geometric characteristics of the spaces to serve.

Diffusers suitable for high height environments have been used for the lower levels.

Eng. Salvi belonging to the Manens-Tifs organisation, affirms:

“The plant design has been integrated with the architectural design from the early stages of the project, using energy simulation in dynamic mode and calculation of natural lighting provided by our Building Physics specialists. It has been made to optimise the design choices on the basis of thermal, visual and audible comfort and of course, of total costs reduction (both building and energy) and CO2 emissions.”

To confirm this view it is possible to list some of the design choices that have been made, like the gallery covers that are composed of 50% high-performance solar cell stained glass windows and the other 50% opaque panels with an acoustic absorption function, while ensuring a good natural light even on the ground floor, significantly reducing solar energy loads.

Even artificial lighting has been designed to further reduce internal loads through LED technology and light intensity adjustment based on the amount of natural light in every condition of the day, measured by internal sensors.

In parallel, the HVAC choice was made in respect to the overall energy consumption esteem in the various options analysed, optimising the components on the basis of LCCA (Life Cycle Cost Analysis) and the lower CO2 impact, which favours technologies that are able to exploit renewable energy sources.