Free cooling of an office building with boreholes
Type: Office, whole-building studies
Consultant: EQUA, Hans Abicht AG
Client: Roche Diagnostics
Summary: An office building cooled with boreholes. Both borehole fields and ambient air heat exchanger could be reduced significantly in size thanks to the simulation.
A new office building with relatively high cooling need (IT services) should be cooled by as much free cooling from boreholes as possible. The heat is provided by a heat pump, taking as much heat as possible from the cooling tanks and the rest from the same borehole field.
The questions were:
A model was created with:
The control measures tank temperatures on different heights as well as borehole outlet temperature and ambient air temperature. Depending on these temperature measurements, the system is switched between the following 5 operation points:
Thanks to the higher planning reliability, the borehole field as well as the ambient air heat exchanger could be significantly reduced in size. The investment costs were reduced by 10 times the costs of the whole simulation service. The created dynamic building model can be reused for fault diagnostics and system optimization during the operation of the building.
Borehole outlet temperatures over 50 years for the system with (above) and without (below) regeneration of the borehole field.