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.
SUITABLE PRODUCTS
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AS AUTOMATIC FILTERS
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
- Filtration degree from 6 microns
Maintenance
- Fully automatic
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HN HYDROCYCLONES
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.
- Remove most of coarse sand
- To be purged periodically
REFERENCES
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.