Protection of heat pumps in collective buildings

In water / water geothermal heat pumps on well-water, exchangers are subject to clogging when the 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. In the presence of sand, a 80 to 200 micron filtration is sufficient; this is the most common configuration. But some well-waters contain very fine clays, which form a deposit on the exchangers and end up clogging them. In this case, it is necessary to put a much finer filtration: 1 or 5 microns.



Alfa hydrocyclones are the most economical solution in the presence of sand. They require manual interventions to drain the tank, but much less frequently than on a cartridge filter.

Water quality

  • Removes 80% of particles above 100 microns


  • Manual drain

AS series filters are especially designed for this application. As they can operate at low pressure, they can be installed directly between the pump and the exchanger, without the need of oversizing the pump nor of adding a pressure sustainer. Filtration between 60 and 400 microns.
See products

  • Filtration degree up from 60 microns
  • Fully automatic

AG series filters are used in the presence of fine clay, thanks to their very low filtration degrees. They operate on network under pressure (2 Bar minimum).
See products

  • Filtration degree from 0,5-1 micron
  • Fully automatic


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.