Protection of heat pump in buildings

In water / water geothermal heat pumps on well-water, exchangers are subject to clogging when water contains suspended solids. These suspended solids gradually clog the exchanger and reduce its efficiency; disassembly and cleaning are then necessary. To reduce maintenance, a good filtration is necessary. 


Most commonly, 80 to 200 micron filtration is sufficient to protect the plates.


For some boreholes containing a large quantity of fine clays, a much finer filtration (6 microns) slows down the formation of deposits on the plates.


These filters are able to operate at low pressure (from 0.5 Bar upstream pressure), which is ideal when the discharge well is directly after the exchangers. Filtration between 6 and 400 microns.

Filtration efficiency




HN hydrocyclones are the most affordable solution if presence of coarse sand. They require manual intervention to purge the tank, but much less frequently than on a cartridge filter.



Demathieu Bard Construction / Consulate of Turkey, Strasbourg (France). Plate exchanger protection filters on a groundwater water / water heat pump heating system. 1st building: 20 m³/h flow rate, 80 μm filtration (AS200 filter), 2nd building: 160 m³/h flow rate, 80 μm filtration (AS400 DN200).

Tempéria Normandie / Building Matmut La Filature, Rouen (France). Geothermal system on open network. 2 pumping 30 and 45 m³/h before exchangers and discharge wells. AS200 low pressure filters.

Engie Axima / Peyrehorade Home for elderly (France). Well-wa­ter filtration to protect a first exchanger before heat pump. Filter AS200 200 μm.

Download: list of references

Hervé Thermique, Milly la Forêt swiming pool (France). Well-wa­ter filtration to protect a plate heat exchanger. Filter AS200 80 mi­crons.

Engie Axima / Romanité museum, Nîmes (France). The heat pump system is protected by 2 filters AG200 3’’, filtration 200 microns.

Tunzini, St Jean de Braye (France). As part of the renovation of a former industrial site, a geothermal heat pump has been installed. Protected by 2 filters AS300 DN150 80 microns.

Suez Lyonnaise des eaux, Rouen (France). Ground water heat ­pump, for a building heating system. Filtration 100μm. 2 Filters AS300 DN150.