As part of the renovation of the building, we need to choose a heat source. We are, of course, interested in the heat source that emits the lowest level of CO2 and is the most energy efficient. The Danish district heating system is known worldwide for its energy efficiency, but the old school building is located outside the municipal supply area, so we have to find a stand-alone heating solution.
Energy can be obtained from the air, water and ground. The ground is the most stable energy source, and there are two different ways to extract its energy. The most common is a horizontal ground source heat pump system, which involves burying pipes in shallow trenches at a depth of 1 metre. The other method is a vertical ground source heat pump system, which involves collecting the heat from a deep vertical borehole of 70-100 metres. Both methods are cost-effective to run, but the setup costs are substantial.
A vertical ground source heat pump system is the most expensive. But a vertical ground source heat system has the advantage that it can store excess heat from the building in the summer months for later use. Another advantage is that it requires much less space compared to a horizontal solution.
Also, the composition and distribution of the local soil layers greatly impact the efficiency level of the two types of ground source heat pump system. Wet soil, such as marshland or clay, will be efficient for a horizontal system. If the soil layers consist predominantly of sand, a borehole will be best.
On the basis of the above considerations, a geophysical survey of the site was conducted, and the conclusion was that a vertical ground source heat pump system will be the most suitable solution for our renovation.
In partnership with geologist Inga Sørensen, we have obtained the necessary local government building permits from Syddjurs Municipality. The drilling work will be performed by Geodrilling and take place at the end of September 2021.
Everybody is welcome to visit Hedeskov School while this drilling work is being carried out. The process will take about a week, and as Inga Sørensen will be present on site during the work, there will be ample opportunity to ask an expert any questions you may have.
When we have scheduled the exact date of the works, we will announce it here on the website and on social media.