Largest ground source heating system underway in Denmark

The construction of the largest ground source heating system that will cater for a 28,000 sq.m. office building is underway in Denmark. The propane based system will be able to deliver a cooling capacity of 1200kW and 750kW heating simultaneously, while it will allow the owner to realise significant energy cost savings.

According to ScanRef, the leading specialised magazine for the refrigeration business in Scandinavia, Vestas, the world’s largest manufacturer of wind turbines, has started the installation of the biggest ever ground source heating and refrigeration system in Denmark that will cater for the company’s new headquarters in Skejby, northwest of Aarhus.

Main system elements

The main elements of the low temperature ground source system, dimensioned by company COWI with components supplied by Johnson Controls, include:

Use of propane refrigerant

1200 kW cooling and 750 kW heating capacity simultaneously

36 km ground source collectors of 40 mm in diameter in the ground between the new building and the existing building

Connection to solar collectors and PV: The ground source system is connected to solar collectors with a surface of 350 square meters. Next to the solar collectors a photovoltaic system with a surface of 600 square meters will be installed. The latter will produce part of the energy that will run the ground source heating system.

Expected energy cost savings of €94,000 per year

The propane system is expected to save DKK700,000 (about €94,000) per year on the Vestas heating budget compared to the district heating system in Aarhus, which is already very cheap. The system has been calculated to have a payback period of less than 10 years.