CARLE

A new wind well controlled

A symbol of the renewal of the Saint-Jean station district in Bordeaux, the In Nova tower will reach a height of 55 meters. Cap Ingelec was responsible for the project management of the HVAC technical batches for this project with its audacious architecture.

A 16-storey building is currently being erected in the immediate vicinity of the Saint-Jean station in Bordeaux. The cube-shaped building is located within the Euratlantique project, which will eventually include 2.5 million square meters of offices, housing and public facilities. The In Nova tower, supported by the developer Carle, was designed by architects Bernard Bülher and Frédérik Dain (Hobo Architecture). It has the particularity of offering 9 floors of offices topped by 7 floors of housing. The two blocks, identifiable by a simple glance, are separated by a garden terrace. Cap Ingelec was entrusted with the technical lots for heating, ventilation and air-conditioning as well as the electrical aspect of the project. The engineering company worked hand in hand and iteratively with the promoter and the architects to solve an equation with several unknowns. The mission was to optimize the energy performance of this HQE Bâtiment Durable certified building without altering its architectural signature and offering a living comfort worthy of its standing. All this while controlling costs with maximum security.

A solution adapted to office use

“We applied ourselves to finding the best solutions according to the uses” explains Véronique Sevrin, Project Manager at Cap Ingelec. In concrete terms, the engineering company opted for fan coil heating for the “office” part via a local heating network. The system allows for a calculation of energy consumption by half-floor with temperature adjustment by individual space. Similarly, a chilled water network provides individualized air conditioning for the offices. A centralized technical management system recovers information and automatically regulates the temperature of the premises according to multiple parameters: lowering of the temperature in the evening and at weekends, minimum heating on unoccupied areas, etc. The positions of the windows were studied to increase the natural luminosity inside while respecting the aesthetic effect desired by the architects with windows of different sizes whose location seems random. More classically, the building benefits from a double-flow ventilation system with energy recovery on the extracted air. For the living quarters, Cap Ingelec chose an underfloor heating system. This solution avoids the use of radiators and allows a room by room regulation.

Extensive wind studies

The engineering company also conducted extensive studies to break thermal bridges between the apartments and the surrounding terraces. Similarly, complex calculations were carried out to simulate the impact of the wind in order to avoid nuisances, whether physical (draughts) or acoustic (whistling). In this respect, the In Nova tower benefits from translucent glass windbreaks which surround all the apartments. Cap Ingelec determined their ideal positions per façade to limit the influence of the wind to a maximum. These glass walls also help to prevent a possible sensation of vertigo. Ventilation simulations also allowed us to show that these high rise dwellings could save on air-conditioning thanks to a satisfactory natural night-time cooling. “Cap Ingelec is accustomed to projects for high-rise buildings and high rise buildings (IGH). Here, the originality of the project comes from the mix of uses. Thanks to our technical approach and our modelling tools, we have brought effective solutions in both cases on the thermal, wind resistance and luminosity levels” concludes Véronique Sevrin.