Examples of Hectron water filtration solutions for heat pump protection in collective buildings

Examples of Hectron water filtration solutions for heat pump protection in collective buildings
Heat pump systems in collective buildings are becoming increasingly popular. In the long term, they offer very advantageous energy solutions. However, they are expensive installations. Moreover, their permanent operation makes them essential to the daily life of a building and it is difficult to envisage stopping them for maintenance. This is why effective filtration solutions are important to protect the heat pump exchangers that are the sensitive part of these systems. Several of Hectron's automatic filter ranges are ideally suited to this role and there are many examples of installations detailed below.

Why is it necessary to protect a heat pump upstream? 

The so-called ground source heat pump on a water borehole essentially works with a system that is rather sensitive to fouling: the plate heat exchangers. Most borehole water obviously contains suspended matter and the exchangers have rather thin piping that is easy to clog. They can then become less efficient and the heat pump's performance will be greatly impaired. Very often, to remedy this kind of problem, dismantling is necessary to carry out a complete cleaning. This has not only a financial cost, but also a significant impact as the system has to be shut down. As is often the case, prevention greatly reduces these consequences. That is why upstream filtration is absolutely necessary. For a relatively low cost at the time of installation, the number of maintenance interventions is greatly reduced, the heat pump's efficiency is optimised and its service life is significantly extended.

The different Hectron solutions for the automatic filtering of your heat pump in collective buildings

There are 3 types of automatic filters that are perfectly suited for protecting heat pumps in collective buildings. These are the HN hydrocyclones, the AS automatic filters and the AG automatic filters.

The use of HN hydrocyclones

This is the most economical and simplest filtration method. It is strongly recommended when the water is not very heavy and the filtration can be light. One of the great advantages of hydrocyclones is that they are very reliable and long-lasting: there are no moving parts on this type of filter, so there is almost no wear and tear. The only human intervention is periodic purging. But, in general, the vertical tank valve is large, so these blowdowns are very effective and fairly spaced out over time. A good example of the application of this type of product is the protection of a plate heat exchanger of the heat pump of the clinic La Cerisaie in Tain l'Hermitage in the Drome. This establishment drew water from a fairly lightly charged groundwater table. There was therefore no need to use a fully automated system. The Gamon heating company therefore used a HNc 80 hydrocyclone for this project, with very satisfactory results, which offers a flow rate of between 17 and 45 cubic metres per hour with a maximum pressure of 10 bars, which is more than sufficient for an installation like this.

The use of AS automatic filters

The use of AS automatic filters is particularly recommended in the case of plate heat exchangers. Moreover, their technical characteristics allow them to operate at very low pressure. A pressure threshold of 0.5 bar is only required upstream of the filter. There are several examples of sites where the heat pump could be protected by an automatic AS filter. The first example is the Hôtel du Département des Hautes-Pyrénées in Tarbes. Groundwater feeds the plate heat exchanger system of a heat pump. The company Hervé Thermique was able to install an AS300 filter with a nominal diameter of 100 mm and a filtration threshold set at 200 µm. Similarly, the buildings of the Turkish Consulate in Strasbourg are equipped with the same type of filtration to protect the heat pumps. These heat pumps operate with a water/water system on groundwater via a collection well and a discharge well and have plate heat exchangers. Demathieu Bard Construction was able to install 80 µm filtration with an AS200 filter for a flow rate of 20 m3/h on a first building and 80 µm filtration with a larger AS400 filter on a second building for a flow rate of 160 m3/h. In the same way, Tempéria Normandie was able to equip the building La Filature de la Matmut in Rouen, Seine-Maritime with AS200 low pressure filters to protect an open circuit geothermal system operating with two pumping systems of 30 and 45 m3/h. Even with a low-pressure filtration system with automatic AS filters, the filtration threshold can be quite high. For example, in Strasbourg, the company Regmatherm was able to install a 200 µm filtration system with an AS300 filter in DN150 for a 13,000 m² training centre, the PAPS-PCPI building, to protect the heat pump exchanger installed on borehole water.

AG automatic filters to protect heat pumps

The AG range of Hectron automatic filters is probably the most versatile filter available and therefore also has a wide range of applications to protect a heat pump. There are two important advantages with these products: they offer a very wide filtration threshold range (from 0.5-1 microns to 500 microns) and their water consumption is rather low thanks to an ingenious suction ramp system for cleaning. Two examples of exemplary projects where AG automatic filters have been installed to protect heat pump systems can be cited. For example, the company Résurgence in Vénissieux in the Rhône region used this type of filter in an Ikea shop. Where conventional filters clogged up very quickly in a few hours, a new solution was proposed with AG400 filters with a filtration threshold of 60 µm. This new system gives satisfactory results and effectively protects the shop's air conditioning system, which is powered by a heat pump. At the Musée de la Romanité in Nîmes in the Gard region, it is a geothermal heating system that is protected by this type of filter. They were chosen and installed by Engie Axima: 2 AG200 filters with 3" threaded inlet and outlet and 200 micron filtration are fully satisfactory.