The National Museum of Science and Technology of Catalonia (MNACTEC), located in Terrassa and housed in the emblematic modernist factory Vapor Aymerich, Amat i Jover, presents significant structural deficiencies in terms of energy efficiency and thermal comfort. The building, which holds considerable heritage value, requires innovative and sustainable solutions that preserve its uniqueness while ensuring visitor well-being.
Within the framework of the European SHERPA project, which promotes the energy rehabilitation of public buildings in the Mediterranean, the Government of Catalonia, through the Department of Culture and the Catalan Heritage Agency, is spearheading the energy renovation of the entire building. Feu Godoy Arquitectura leads the project and has entrusted Esitec with the energy audit and the design of the installations.
Based on the energy audit, an annual reduction of 598.95 MWh and 150.79 tonnes of CO₂ is projected, resulting in an overall economic saving of €18,262/year. The centralized energy management system allows real-time consumption adjustments, while the waste plan foresees the reuse or recycling of 70% of the materials.
A basic and executive project has been developed with the aim of reducing fossil energy consumption by at least 30%. The actions include the renovation of the building’s HVAC system, installation of a 20 kW photovoltaic system, replacement of lighting with LED technology to improve energy consumption, and thermal insulation enhancement using materials compatible with heritage preservation. The project also includes restoring natural ventilation with 77 fans installed in the original sawtooth openings.
For the HVAC system in the main hall, reliance on diesel boilers and a conventional chiller is eliminated, replaced by a high-efficiency water-to-water heat pump with heat recovery. Three air handling units (AHUs) supply and extract filtered air, and a hydraulic circuit with inertia tanks and variable-speed pumps optimizes system start-up and shutdown. All parameters (temperatures, flows, pressures, valve states) are connected to the BMS, which schedules operation based on real-time demand and occupancy to maximize the COP up to values close to 4.0. This results in a reduction of over 40% in diesel and electricity consumption for climate control, with a payback period of eight years.
Similarly, in the reception building, the three existing direct expansion units are replaced with heat recovery systems integrated into a new primary-secondary circuit with dimensioned pumps and pipes with variable speed drives. The recovery unit harnesses the refrigerant’s energy to produce DHW or supplement heating, and the BMS manages “work” and “leisure” scenarios to adjust output based on use. This intervention cuts the electricity consumption for climate control at the reception by 15%, with a payback period of fourteen years.
Regarding the restoration of natural ventilation, 77 fans are installed in the original sawtooth openings, replacing the historicist covers. The mixed ventilation strategy combines natural draught with mechanical supply and extraction under BMS control, responding to internal temperature sensors and weather forecasts. This reduces thermal loads by up to 25% during summer peak hours and provides a healthier environment without significantly increasing electricity consumption.
Concerning improvements to the building envelope and thermal insulation, partial restoration is carried out on the sawtooth roof, preserving the original openings. A continuous fiberglass insulation layer with a sealed membrane is installed, minimizing winter heat losses and summer gains, resulting in up to an additional 10% energy saving in HVAC systems.
