May 20, 2020

Automatic water treatment and filling units to protect the circuits against limescale and corrosion

Caleffi Hydronic Solutions has developed a complete innovative system to protect air conditioning systems. With the Automatic water treatment unit - 580020 series, water softening or demineralisation cartridges, and the Automatic compact charging unit with backflow preventer - 580011 series, the circuits are protected against limescale and corrosion. In full compliance with the most stringent applicable regulations while respecting the environment.

Product advantages of Caleffi automatic water treatment units

  • A single group for softening and demineralisation
  • Compact dimensions for the hydraulic part and treatment cartridges
  • By-pass for adjusting water hardness after treatment
  • It can be integrated with a filling unit and compact backflow preventer in compliance with the EN1717 standard

In the last few years, air conditioning systems have become extremely efficient, offering increased performance and reduced consumption, with a lower impact on the environment in terms of both energy savings and reduced polluting emissions. However, in order to ensure high standards throughout the system’s life cycle, appropriate precautions must be taken.

The characteristics of the water fed into the closed circuit are of crucial importance. The UNI8065:2019 standard establish that water treatment through chemical additives and water softening and demineralisation systems are essential steps to ensure maximum energy efficiency. In fact, if the water in the closed circuit used for charging is very hard, it will produce a lot of limescale.

As the water heats up, the calcium and magnesium salts crystallise and deposit themselves on the exchange surfaces or in the narrowest passages of the system, thus creating obstructions that may prevent the medium from flowing or block the adjustment devices.
Electrical conductivity, instead, indicates that the water is not only corrosive but also causes limescale deposits.
The higher this parameter is, the greater the amount of salts present that can damage the metal components, which can become thinner, or cause micro-cracking. Therefore, keeping these values under control will help chemical air additives to protect the entire air conditioning system against corrosion and limescale.

Why did Caleffi developped these new water treatment units?

This is why Caleffi Hydronic Solutions has developed a complete innovative system: the new Automatic water treatment unit - 580020 series to be installed on the inlet pipe in the closed circuits of heating and cooling systems. An extremely small body contains all the accessories required for proper water treatment: it is an ideal solution, especially for central heating systems where there is little space available. The controller on the treatment unit performs a triple function:

  • a volume meter allows the charging flow rate and the amount of water loaded to be checked;
  • a built-in conductivity measuring cell verifies the effectiveness of the treatment and shows when the cartridge needs to be replaced;
  • an electronic system allows the treatment to be parameterised with an interface function to monitor charging.

The user can also choose the post-treatment hardness value. Thanks to a by-pass upstream of the cartridge, the amount of untreated and treated water to be fed into the circuit can be adjusted in order to obtain a mixture at the desired value of °f (or °dH). In fact, full softening would bring water hardness to a value lower than 1 °f, which for some systems can be too low. This function is not necessary for water demineralisation, since the controller itself will determine when the selected electrical conductivity limit has been reached.

Discover the wide range of cartridges for softening and demineralisation treatment units

Thanks to the wide range of cartridges available, this group can be adapted to different types of systems, depending on the treatment to be carried out and water content (system size). Disposable 2.7 and 4.5 litre cartridges are available in the softening version and in the demineralisation version, which are ideal for filling medium-small systems. The cartridge must be applied directly to the treatment unit. Once charging is complete, the unit can be simply intercepted without removing the cartridge, which can still be used for regular refills during system operation.
Two larger refillable cartridges are also available for demineralisation. They are ideal for filling larger systems, offer a higher treatment capacity in terms of water volume and can be regenerated with the appropriate refills. Once filled, a disposable cartridge can be installed for regular maintenance.  Water subjected to these treatments is highly hazardous to health and is no longer suitable for human consumption. In compliance with the EN1717 standard, a BA-type backflow preventer must therefore be installed to protect the domestic water mains.

Combine the automatic water treatment unit with the automatic compact charging unit with backflow preventer 

As an accessory, Caleffi Hydronic Solutions offers the Compact automatic charging unit - 580011 series, which is composed of two shut-off valves with an inspectable strainer, a BA-type controllable reduced pressure zone backflow preventer and an automatic filling unit. It is installed on the water inlet piping in closed circuit heating systems. The group stabilises the pressure of the system at a preset value, automatically topping up with water as required. The backflow preventer prevents the contaminated water in the closed heating circuit from flowing back into the tap water supply mains. Since the backflow preventer is tilted, the 580011 series unit can be installed on vertical pipe sections, separated from the treatment unit, thus meeting the installation requirements of each system. In conclusion, the special connection fitting ensures direct connection to the water treatment unit, thus forming a single filling line.