Connecting the huge APG headquarters building in Heerlen to the mine water system was a particular challenge. The office building, built between 1972 and 1974, in no way met the requirements of a modern office building, least of all in terms of energy consumption. Prior to the renovation and changes to the energy installation the annual natural gas consumption was around 4.2 million m³.

Data centre heat recovery
The qualitative improvement and total energy approach to the improvements of the installation in terms of delivery and ventilation made it possible to achieve the first big energy savings. The APG data centre continuously generates heat that used to be discharged on the roof, effectively dumping useful energy. Today, using heat pumps supplied with cold mine water to carry off heat from the data centre, about 21,000 GJ of heat is recovered annually. Of this 21,000 GJ, each year around 6,000 GJ is used to heat the building’s 32,000 m² of office space. The remaining 15,000 GJ is returned to the mine water infrastructure for use by other customers, such as Arcus College.

Substantial CO2 reduction
This residual heat contribution is particularly unusual for an office building from 1972/1974 with a CO2 reduction of 118% to 130%, an achievement that has not been duplicated by any other office building from this period or since. As a result of the mine water connection (Minewater 2.0), an energy system with a total of eight heat pumps and a building management system, natural gas is now only used to a very limited extent, during the coldest part of the year. That is quite an improvement compared to the previous consumption of around 4.2 million m³/year.