The mountain residence “Les Hauts de la Drayre” is being reinvented thanks to Giacomini's apartment thermal modules (MTA).

Led by the municipality, the project combines preservation of the existing buildings and partial reconstruction to improve the site's energy performance, modernize the equipment and offer high-end comfort to its future occupants.

Specializing in the production of components for heating and plumbing systems, GIACOMINI was approached to support the technical design of the project and provide a comprehensive solution for domestic hot water (DHW) distribution within a holistic energy performance approach. Their technical proposal is based on the integration of 69 SM556 apartment thermal modules (ATMs), with 36 and 50 panels. These modules enable decentralized DHW production, improved flow control, and temperature uniformity throughout all apartments, while also simplifying system maintenance. Heating and DHW production will be provided by 15 heat pumps of 16 kW each, supplemented by electric resistance heating networks for peak demand.

STREIFF, the company in charge of the work, deployed its workshop prefabrication and digital modeling capabilities to anticipate site constraints and guarantee quality of execution. The installation of GIACOMINI's MTA modules is already complete in buildings A and B, representing more than half of the installed system.

A construction site in mountainous territory

At the initiative of the municipality of Vaujany (38), the “Hauts de la Drayre” hotel residence is undergoing a complete renovation, transforming a former tourist building into a four-star hotel complex managed by Vacancéole. The project modernizes the aging original structure to offer more spacious and efficient accommodations.

Originally built to house 91 apartments, the residence will now have 65, designed with a high-end aesthetic. The work includes the partial demolition of the building, the reconstruction of the staircases, the removal of the original balconies in favor of large terraces, the renovation of the roof, and the installation of external thermal insulation.

The project comprises four buildings: three accommodation blocks and a central wellness center (Rif Fontan), housing the reception area and common spaces. Buildings A, B, and Rif Fontan are scheduled for delivery in November 2025 for the start of the season. The final building will be delivered in spring 2026.

The municipality, which owns the residence, retains control of the site's energy management, in order to guarantee comprehensive monitoring of water and energy consumption.

Operation is entrusted to Vacancéole, a company specializing in the management of tourist residences in the mountains. This arrangement avoids the proliferation of individual meters and maintains centralized monitoring of usage, optimized by a Centralized Technical Management (CTM) system installed in each building.

69 MTA of GIACOMINI selected for domestic hot water distribution

Initially not prescribed in the project specifications, GIACOMINI was able to convince through the quality of its technical support and the solidity of its expertise, demonstrated from the tender stage through a complete and qualitative technical study.

Already convinced by the quality of the products and the rigor of the service provided by the brand on other sites, STREIFF, a company in charge of the renovation work, chose to entrust it with the supply of apartment thermal modules (MTA).

GIACOMINI, in collaboration with the fluid engineering firm COTIB from the design phase, formulated a coherent and technically turnkey proposal. The plan featuring 69 MTA modules – SM556 models with 36 and 50 plates – was quickly selected to ensure the distribution of domestic hot water.

Prefabrication workshops located away from the construction site to anticipate constraints and guarantee the quality of the installations

To anticipate the constraints of this mountain construction site, in particular to ensure opening from the start of the season but also to gain efficiency and guarantee the quality of the installations, STREIFF relies on its own prefabrication workshops directly integrated into its premises based on the outskirts of Grenoble in Saint-Martin-le-Vinoux (38).

This prefabrication process is preceded by a complete digital model, allowing for control of available space, anticipation of each stage, and prevention of any on-site disruptions. These workshops involve recreating, at full scale, the future technical rooms of the building to ensure rapid implementation, in accordance with the plans, while optimizing coordination between the various stakeholders.

The hydraulic systems are fully assembled, checked, and pressure-tested before being disassembled and reassembled on site. These workshops have cranes and assembly areas designed for heavy loads, ensuring high-quality assembly in a safe and controlled environment.

This organization avoids the constraints associated with on-site interventions, often marked by restricted volumes and the simultaneous presence of several trades (masons, electricians, plasterers, etc.).

Thanks to this prefabrication, each MTA, delivered and fully assembled, requires only about two hours of connection (excluding template assembly) for a team of three to four plumber-heating installers supervised by a site manager.

Over 50% of MTAs already installed

Today, the installation of the MTA (Multi-Functional Areas) in buildings A and B is complete, representing more than half of the modules installed. The remaining buildings, C and the wellness center, will be equipped in succession, following the same technical and assembly principles.

Connected from the top or bottom, all modules incorporate a bypass to maintain continuous circulation of domestic hot water, prevent stagnation and thermal shock, and ensure immediate and on-demand responsiveness. Furthermore, they ensure faster and safer commissioning, as the network segmentation allows each module to be isolated for testing or maintenance work.

This design makes the MTAs autonomous, easily dismantled, and perfectly integrated into the collective network. Centralized management via the BMS allows for adjusting temperature setpoints, monitoring flow rates, and synchronizing the modules to prevent pressure or temperature imbalances.

In return, the MTA (Multi-Tank Air) system generates more piping in the apartments because each unit acts as an interface between the primary network dedicated to domestic hot water production and the secondary network for its distribution. This implies a primary supply line to each module, as well as a separate secondary network for hot and cold water within the dwelling, run directly through ceilings, partitions, or behind wall coverings. The primary heating networks are made of electro-galvanized steel, while the secondary distribution networks are made of multilayer pipe. Crimped pipes were chosen over welded ones to ensure a perfect seal while reducing installation time by 30 to 40%.

Heat pumps and electric resistance heaters for the production of heating and domestic hot water

To integrate this renovation into an environmental approach, the primary heating water is produced from heat pumps.

Five 16 kW heat pumps supply building B – the largest – and four additional units supply buildings A and C, while the wellness center – Rif Fontan – benefits from two heat pumps. This heated water is then stored in a technical room and distributed to the GIACOMINI MTA units, which manage the heating (radiators) and the production of domestic hot water (DHW) thanks to their integrated heat exchanger.

To meet peak consumption during winter periods, such as skiers returning at the end of the day, the heat pump modules use a high-efficiency, dual-circuit refrigeration system that maintains the set temperature at 65°C to ensure occupant comfort and prevent any hot water shortages. This system is integrated with a connected control device to adjust production according to actual occupancy.