Duinoord under the Kurk
In this project we will investigate the effect of a Sedum cork roof on insulation in winter and cooling in summer. We are also organizing a cork collection campaign with youth to create awareness for this valuable raw material. This project is made possible by the efforts of the volunteers of Duurzaam Duinoord with support from the municipality of The Hague (Energy from the Neighborhood Challenge).
There are many flat, non-insulated roofs in Duinoord. In winter, an average of 30% of the heat is lost through the roof, which is reflected in the energy bill. One solution is roof insulation, but this is a major investment that the homeowners' association often postpones, especially if the bitumen is still good. We also often see that the landlord does not cooperate.
In summer, 40% of the heat comes in through the roof. More and more people are considering air conditioning, which costs a lot of energy. One solution is a sedum roof that lowers the temperature of the space below by 5 degrees. Unfortunately, sedum does not or hardly insulate. A possible solution is the combination of cork (insulation) and sedum (cooling).
Pilot
The company Earthkweek supplies sedum-cork cassettes. The cassettes measure 50x33 cm and are easy to install and move. Cork is a well-known insulation material that has been used for a long time. A lot of research has also been done into the cooling effect of sedum. The combination we want to use with sedum and cork is much less known. That is why we want to measure the effect of this application on the temperature of the roof surface and compare it with three variants:
- Standard gravel roofShade from solar panelSedum/cork
The three roof surfaces on our test roof have the same amount of sunlight and the space below them has the same temperature. By measuring the temperature at these points for a year, we can determine whether/which there is a difference in temperature. It is expected that the sedum/cork roof will heat up less quickly in the summer and insulate in the winter. We will find out how well this works!
Cork hunt
Duinoord is rich in cork. These are hidden in the kitchen drawers of our residents. Unfortunately, this cork can only be returned in a few places, is not allowed in the organic waste and often ends up as residual waste. And that is a shame because cork can be recycled very well, for example in the sedum cork cassettes. That's why we're calling on the cork hunters for help. These are children from the neighborhood who go door to door to collect these corks. They receive a premium for the corks submitted and there are great prizes to be won. In addition to recovering the valuable raw material, there is an educational element in which we create awareness for this valuable raw material among all residents through youth.
Continued after 2024?
If the pilot is successful, we want to organize a collective purchasing campaign in 2025.
Partners
Municipality of The Hague and EarthKweek.
Update-jes
May 2024 - The sun is higher, the days are getting longer. We see that the temperature of the roof surface gravel rises considerably, with sun and sedum cork remaining a number of degrees lower, with sun peaking earlier than sedum cork.
April 2024 - Although spring has been quite wet so far, the days are getting longer and this is reflected in the measurements. Particularly when the sun shines for a longer period of time, sedum is increasingly cooler than gravel. We are also increasingly seeing a larger temperature difference, with the gravel heating up faster than the roof surface with sedum. The differences are now limited to 1 degree, we expect this difference to increase as the sun shines longer. What is also striking is that the roof surface with solar panels is much warmer than gravel. The hypothesis that this roof surface would remain cooler due to the shade of panels therefore appears to be incorrect.
March 2024 - It's spring again! We look back on a short frost period, lots of rain and longer days. We have different observations. We see that in wet weather the difference between the roof surfaces is small. But when it gets really cold, this often precedes a dry period. As the sedum cork dries, it appears that the insulation value increases. When the temperature rises we see the opposite, but to a much lesser extent. The interim conclusion is that sedum cork always insulates (somewhat) compared to a gravel roof. But when it gets really cold, sedum cork insulates substantially. The disadvantage of storing cold during warming appears to be limited.
January 2024 - Measuring has begun! We have programmed a dashboard in which the data from the sensors are displayed in one image. You see the temperature on the y-axis and the time on the x-axis. We can adjust the period so that we can compare different days. The images below show a number of examples of what we have seen. In the near future we will look at the effect of temperature on the three roof compartments over time.
December 2023 - The sedum-cork cassettes have been installed. We used a roof lift to start removing the gravel layer. There was 5 cm of gravel, which amounts to 75 kg per m2. Instead, the sedum-cork cassettes have been installed, with a maximum weight of 51 kg. After laying the root-resistant layer, the sedum cork cassettes could be placed. These have a size of 50x33 cm. For good water drainage, an edge of approximately 10 cm has been left between the roof domes and chimneys, which is filled with gravel. The sensors have been installed and the pilot has started. Apart from the technical facts, the roof immediately looks more attractive with sedum cork!
November 2023 - We have set up a dashboard in which the measurement data is visualized. For the technicians among us, here is an explanation of how we went about this: To record the measurement data, a mini computer (Raspberry Pi) was used that receives the measurements from the 4 RuuvTag sensors via Bluetooth. For good reception, the minicomputer is placed as close as possible to the ceiling and connected to the network via a Devolo LAN connector that is connected to an unused light point. In terms of software, we use a data collector (RuuviCollector 3.8k) with a database (InfluxDB 686), where the data is visualized in a Grafana dashboard (427)
Presentation Duinoord under the stool and Jelle at The Hague FM, fragment November 2, 2023