Energy-efficient renovation of schools - a holistic approach on natural light, natural ventilation and natural materials
The project will demonstrate that using natural materials in exterior and interior facades e.g. eelgrass as insulation material and clear glass in the windows can achieve greater sustainability, lower energy consumption and a better indoor climate with emphasis on daylight quality, expanded degree of natural ventilation and better room acoustics.
With the energy requirements in BR15, we have in practice reached a limit to how far energy consumption in buildings can be reduced. Further tightening in Building Class 2020 has led to an unfortunate development, where focus has been removed from sustainability, instead aiming at 'circumvention' of the purpose of the building regulations. Reaching the requirements and the energy frame instead has become a question of how many square meters of solar cells to be placed on the roof, although this is rarely an appropriate or sustainable solution.
This project seeks a new way of focusing on overall holistic considerations and sustainability, using natural building materials with great positive importance for both indoor climate and total energy consumption. The project will demonstrate the effect of using natural materials in exterior and interior facades, using seegrass as insulating material and clear glass in the windows to achieve greater sustainability, lower energy consumption and a better indoor climate with emphasis on daily quality, extensively of natural ventilation together with improved acoustics.
Demonstration takes place through a comparative analyzis of two identical 1: 1 research rooms (classrooms), the first room build using natural materials and the other room using state-of-the-art materials and technologies, respectively. In a later Phase II (not part of this application) the experiences from and the results of the project will part of a full demonstration project for a newly built school.
This project develops and tests a new demand-controlled indoor climate solution called NOTECH, based on natural ventilation and natural materials. The project investigates the impact of the NOTECH solution on indoor climate and energy consumption. The study is carried out in a primary school, comparing a classroom with the NOTECH system to another classroom with a conventional solution, based on mechanical ventilation. The NOTECH system integrates light, air and sound, and integrates special filters made of eelgrass, combined with sun chimneys and especially high-transmitting glass types, in a new demand-controlled natural ventilation system.
Eelgrass (Zostera Marina) stores CO2 directly from the atmosphere in off-shore sediments, storing CO2 for hundreds of years. Smaller, excess amounts of eelgrass wash ashore along the Danish coasts every year. In this project, these materials are utilized as insulation- and filtermaterials in the NOTECH system. Because eelgrass has a natural embedded content of salt, it also is fire-retardant. All in all, these properties mean that eelgrass has enormous potentials in architectural planning, especially when it comes to indoor climate and embedded CO2 in building materials.
The results of the study indicate that mechanical ventilation is not always the most sustainable solution and point to other paths when it comes to obtaining and maintaining a good indoor climate in schools. Overall, the results of the project show that both the demand-controlled natural ventilation system NOTECH and the mechanical ventilation system, at a load of 16 students and 1-2 teachers, could achieve satisfactory indoor comfort temperatures, relative humidity and noise levels, as well as CO2 levels under 1000 ppm.
When it comes to the health, wellbeing, concentration and learning, the quantitative results show that students experience more outside noise in the classroom with the NOTECH solution compared to the classroom with the mechanical solution (p=0.03). The results also show that the sleep quality is significantly better for students in the classroom withthe NOTECH solution, compared to the mechanical solution (p=0.007).
The results of the study show large differences between the two systems in terms of total installation costs and estimated operating costs for electricity, heating and maintenance. These costs turn out to be significantly lower for the NOTECH solution, amounting to a level of only 35% of the mechanical ventilation system.
Finally, the results show that the NOTECH solution provides a much smaller embedded CO2 load for building materials, reducing the overall CO2 footprint by 95% when compared to the mechanical ventilation solution.
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Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| Teknologisk Institut | ||
| Aalborg Universitet (Fredrik Bajers Vej) |
