Energieffektiv renovering af skoler: Dagslys, naturlig ventilation og naturlige materialer. Resultater fra en pilotundersøgelse NOTECH løsning vs. mekanisk ventilation

Carlo Volf, Klaus Martiny, Mathias Andersen, Bodil E Pallesen, Jakob Markvart, Kjeld Johnsen

Research output: Book/ReportReportResearch


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.
Original languageDanish
Number of pages28
Publication statusPublished - Dec 2020

Bibliographical note

Denne rapport er støttet af Elforsk, projektnummer 350-048 og A & E Danielsens Fond.

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