Groundwater cooling reduces CO2 and power expenses for cooling system operation by 80 per cent

When ATP Ejendomme’s new office building on the Langelinie quay in Copenhagen called Pakhuset (the warehouse) is ready for occupancy in early 2015, groundwater cooling will be used to reduce both power consumption and CO2 emissions, thereby saving money.

​Thanks to the groundwater solution, an annual water consumption of 180,000 m3 will result in a power consumption of around 55,000 m3/year. In comparison, traditional cooling would result in a power consumption four-five times as high. The result is an expected CO2 reduction of 75-80 per cent and a similar reduction of the operating expenses for power.

Ground water saves resources thanks to constant temperature
Jan Stæhr, Market Director in COWI’s business unit of Water and Environment, explains why groundwater cooling was chosen: “Traditional cooling comes with a relatively high energy consumption as well as high operating costs. Seawater cooling would be the most obvious choice because the building is located near the sea, but sea water is relatively warm in the summer when the need for comfort cooling peaks, whereas ground water maintains a constant temperature of 10-11°C. In other words, ground water has significantly higher cooling potential during summers.”

“During our study of the layers underneath the building, we developed and applied a special 3D groundwater model, which covers the hydrogeological conditions of the entire Copenhagen area. The study detected sufficient local groundwater resources, which may be utilised in a sustainable manner to cool the building. Ground water in the area consists of, among other things, percolating salty sea water, so ground water is utilised in an environmentally sound manner, which was a key focal point in the development of the project.”

“Last but not least, the operating costs of a groundwater cooling system are considerably lower than the operating costs of a seawater cooling system,” continues Stæhr.

Sustainable landmark on the Langelinie quay
The sustainable solution for cooling Pakhuset is part of ATP Ejendomme’s goal to create a building that in all aspects respects the climate and the environment, while securing financially sound operation.

Mette Munkedal Tange, Project Director at ATP Ejendomme, says: ”The solution supports our focus on low operating costs and strong solutions. Overall, we find it crucial to ‘build for the future’ – both in terms of the environment and the project economy. For instance, in order to fully reap the benefits of the groundwater cooling solution, the building design has to include low heating and cooling needs, and the building structure has to match the cooling solution. So, the earlier in the development process we integrate sustainability, the better and more coherent solutions we can create. We believed we’ve succeeded in doing so in this process, and we’re looking forwarding to welcoming our tenants in early 2015.”