State of Progress | Constructed (completed May 2005) BMS and Monitoring system now being commissioned | ||
Building Description | Refurbishment of existing building and new construction (2200 m2) Situated on the outskirts La Tour de Salvagny, 45,8º | ||
Expected Energy Demand (kWh/m2/yr) | Standard Building | Eco-building | Saving |
183 | 128 | 30% | |
Renewable Energy Systems contribution | 6,5 kWh/m2/yr | ||
The works were undertaken in two phases; Phase 1 - the construction of 5 new classrooms, a computer room and a new library, as well as the construction of the buried earth pipes, the ventilation treatment and control system and the rain water collection tanks. Phase 2 - complete refurbishment of existing building, from insulation to window openings and glazing to floor coverings and the ventilation system.
The choice of materials used in the project was a principal objective, as the community wanted low impact, low energy materials that would create a healthy environment. Avoiding toxic ethers, Volatile Organic Compounds (VOCs) and metal particulates was a priority.
New classrooms are made from pre-formed vapour treated wood particleboard assembled on site, insulated by 120mm of mineral wool. Interior walls and separations are gypsum fibre board. The facades are low maintenance, long life Trespa flat panels made of wood fibres and resin.
The School has two rain water collection tanks of 30m3 each; rainwater is collected and supplies all toilets flushes, and will be connected to the grounds watering system in the future. Last winter 100% of flush water came form the rain water tanks, demonstrating the viability of rain water use.
SARA Bulletin 3 reference:
“Focus on the Tour de Salvagny Eco-building”
http://www.sara-project.net/IMG/pdf/Sara_bulletin_3_april_2006.pdf
A consultative committee established a list of priorities that have resulted in buildings designed as low inertia structures that can be heated and cooled quickly. The school has a relatively low occupancy rate and is unoccupied for long periods of time, especially during the summer holidays. No energy is wasted heating or cooling an empty building, and careful design, and the use of buried earth tubes for summer cooling and extra ventilation has aimed at comfortable conditions despite the lack of thermal mass.
The building’s energy consumption has been minimized through good insulation, a high performance condensing gas boiler, innovative automatic lighting and variable speed ventilation.
| zone | French Regulation min U-values (RT2 000) | proposed values + |
|---|---|---|
| outer wall | 0.47 | 0.25 |
| roof | 0.47 | 0.19 - 0.24 |
| groundfloor | 0.43 | 0.31 - 0.27 |
| glazing | 2.9 | 1.7 |
Project deliverables reference:
D17, 07/2005
http://www.sara-project.net/IMG/pdf/SARA_D17_Final_Report.pdf
The new classrooms are semi-independent boxes, reached by enclosed corridors that link the new classrooms to the old building, whilst creating isolated private areas for each classroom, that have been turned into classroom gardens. The separation between classrooms also ensures an excellent acoustic environment for building users.
The Windows hasve been designed for acoustic as well as termal insulation. The frames are mainly wood although they include a metallic exterior shield to protect the wood and reduce maintenance.
Project deliverables reference:
D8, 08/07/2005
http://www.sara-project.net/IMG/pdf/SARA_D8_Final_Report1-25.pdf
The building design has put the emphasis on natural lighting in all classrooms. Classrooms in the existing building have had extra windows added, and new classrooms have a double orientation for all day natural light. Lighting simulations with DIAL indicate that daylight will supply 60% of the lighting needs in new classrooms and 40% in existing classrooms.
Classroom lighting is semi-automatic, occupiers have a large amount of control over the lighting level; Once the desired lighting level is selected, the system will then automatically adjust the intensity of artificial lights to keep lighting levels constant.
High performance T5 (16mm) lights with electronic ballasts have been installed in all classrooms. Combined with the automatic control, and movement detectors, lighting is expected to use from 5 to 9kWh/m² with an installed power of 6 to 11 W/m² depending on room use.
High performance lightings (100 lumen/watt with electronic ballast) are used in order to achieve a very low electricity needs for lighting (5kWh/m²SDO).
Excessive light and direct sunlight is controlled by exterior blinds.
The ventilation system is a simple flux forced air system, that supplies classroom with pre heated / cooled air form the ventilation treatment centre and buried earth pipes. This choice means that air temperature is uniform across classrooms, whilst allowing high ventilation rates ensuring good air quality. Ventilation in classroom is controlled by movement detectors, unoccupied rooms are not ventilated.
Buried heat pipes
A system of buried earth pipes modifies ventilation intake air temperature, pre-warming in certain months of winter and cooling in summer.
The system consists of parallel 25m long 200mm polyethylene pipes buried in a sand bed with a combined capacity up to 8000m3/h and an air speed of 3m/s. A grade of 1% and system of filters in the ventilation control system ensures good air quality, and a grade of 1% allows evacuation of condensate. The Building Monitoring System determines if the ventilation air should be taken from the buried earth pipes or the normal inlet, according to the temperature of the two sources.
To evacuate the excess of heat loads accumulated during the day, free cooling (through ventilation) can be used to reduce room temperatures.
In the summer of 2005, the buried earth pipes maintained in-building temperatures identical or lower than outside, effectively removing all the heat generated by the building occupants.
A 14kWp grid connected photovoltaic system is installed on the roof of the school. The system, comprised of 6 series, is installed in part on Consol supports and in part on the sloped roof of skylights. The system, which is oriented south-west, is expected to produce 14 400kWh/ year.
All modules are Tenesol T1800, 190Wp multicrystalline modules. The SMA Sunny Boy inverters are connected to an Energrid data logger. Production data will be displayed in the School lobby, to educate and inform the building occupants.
The electricity produced is sold to the local utility, EDF at 15.25c€/kWh, a price that is significantly higher than the cost of the electricity bough by the School.
SARA Bulletin 3 reference:
“Focus on the Tour de Salvagny Eco-building”
http://www.sara-project.net/IMG/pdf/Sara_bulletin_3_april_2006.pdf
Project deliverables reference: D12 20/12/2005,
http://www.sara-project.net/IMG/pdf/D12_Selection_and_installation_of_Components.pdf
Building Management System (BMS)
The school of la Tour de Salvagny will be connected to a general BMS, called GTC for Gestion Technique du Bâtiment, as every building own by the municipality.
The BMS will monitor the performances of the photovoltaic system (energy production, energy consumption, irradiance, etc.) and the Canadian wall (air flow, electricity consumption, air temperature, etc).
An active management system will be use to control heating, ventilation and lighting in every classroom.
Monitoring and analysis results
Actually, the monitoring system is partial because of the unreliability of some data due to technical problems. Tour de Salvagny is working to resolve these technical problems, however certain data such as local weather conditions (temperature, humidity, etc.) and the electricity production of the photovoltaic installation are already displayed on-site and stimulating student and parent interest.
The Primary School extension and renovation began in 1999 with the creation of a Consultation Committee. The Committee was comprised of parents, teachers, educational authorities and local councillors. Together they developed a list of requirement and priorities that included an ecobuildings requirement. This committee met regularly over the duration of the design competition, detailed design and construction process.
The children have also been involved in the construction process, learning about renewable energies and building their own solar houses, helping them to understand the reason why their school building is special; they will also be able to follow the building’s energy consumption and production on a large screen display in the school lobby.
Energy Education
The renovation and expansion of the school with low energy consumption and renewable energy production standards was a good opportunity to educate the children to energy saving and environmental issues. The primary school of Salvagny is contributing to the awareness of the pupils, professors and visitors through the graphical user-friendly interface, which inform about weather conditions and photovoltaic installation electricity production. The design of the user-friendly interface enables easy reading and comprehension by children.
Besides they organised visit of the installations for the pupils who are explaining their experience in the website of their school (http://e.guion.laclasse.com/spip.php?article62).
In parallel, the local Gazette highlighted the primary School’s Pedibus (pedestrian bus), another demonstration of the schools and students involvement in energy efficiency. Parents take turns accompanying the bus for a safe arrival at the school and each stop.
The buildings energy consumption has been minimized through good insulation, a high performance condensing gas boiler, innovative automatic lighting and variable speed ventilation. The insulation efficiency will be 26% better than the legal requirement (Ubat=Ubatref-26%) with low inertia design to minimize heating costs.
Positives
Negatives
Thermal insulation problems: IMAGE HERE
EVENTS
Visitors, architects, engineers, local councillors and even students regularily visit the school.
PROPERTY DEVELOPER
Partner Nº12 The City of La Tour de Salvagny, TSALV
http://www.salvagny.org/
ACTORS INVOLVED
Mairie de la Tour de Salvagny
http://www.salvagny.org/
Agence Tectoniques (architect)
Quadriplus groupe (engineering office) http://www.quadriplus-groupe.fr/
Etamine (engineerings) http://www.bet-etamine.com/
