Electronic water softener: what is important to know?

Sistema antical de efecto capacitivo

Before choosing an electronic water softener, it is important to consider and understand the technological differences that can affect system performance. 80% of the systems available on the market are based on the laying of coiled cables to the pipes (capacitive effect systems). This system is also known as an electronic water softener, although the operation and disadvantages of this system are not always adequately explained. On the other hand, Dropson has developed a very efficient technology that avoids the disadvantages of electronic water softeners with a capacitive effect.


How does lime form?

In order to understand the differences between the two systems, it is necessary to first understand some basic concepts that we will simplify later on. Water contains calcium and bicarbonate (1), which are the causative components of lime. The more the water is loaded with calcium, the more the crystallization of the lime is favoured. When the water is energized (2), e.g. by an electrical resistance, the temperature rises. Calcium and bicarbonate crystallise to form the lime that adheres to the heating elements (3) of the system.

Cómo se forma la cal

  Lime formation process. Steps 1, 2 and 3


How do I recognize a capacitive effect system?

The electronic capacitive water softener consists of an electronic box connected to two insulated electrical cables, also called antennas. These cables are wound over the pipes at the main water inlet of the installation.

Sistema antical de efecto capacitivo


What is the capacitive effect?

To understand the capacitive effect we are going to observe a physical experience: when rubbing a plastic ruler with a cloth and approaching it to a flow of water from a slightly open tap, we can see that the water diverts its trajectory and is attracted to the ruler.

Ejemplo de efecto capacitivo

Capacitive effect.

This physical experience is explained by the very structure of the water molecule. Water is a bipolar molecule, that is, it has a positive and a negative side. By rubbing the ruler with a cloth we have negatively charged it. As the opposite poles attract each other, the ruler attracts the positive side of the water molecule and diverts the flow path.

El efecto capacitivo posee similitudes con la experiencia de la regla de plástico. Un cable eléctrico común está compuesto por dos partes:
la parte interna conductora (el hilo de cobre) y la parte externa aislante (un polímero).

The capacitive effect has similarities with the experience of the plastic ruler. A common electrical cable is made up of two parts: the inner conductive part (the copper wire) and the outer insulating part (a polymer).

When a positive current passes through the copper wire, the outer insulating part of the electrical cable is negatively polarized.

Ejemplo de hilo de cobre con aislante

Example of cooper wire with insulation.


How do electronic water softeners with a capacitive effect work on water?

An alternating current (once positive and once negative) is passed through the wires wound around the pipes. The water molecules that pass through this capacitive field are attracted and repelled successively. In this way we alter the structure of the water and we will favour the crystallisation of the calcium and dissolved bicarbonates to form non-scaling microcrystals of lime.

Descalcificadores electrónicos


What are the inconveniences of the capacitive water softener?

1. Random yield due to the permissiveness of the materials

The performance of this system depends primarily on the permissiveness of the materials. It should be noted that these systems are installed in existing installations. We can find a great variety of materials that compose the pipes: copper, PVC, cross-linked polyethylene, galvanized steel, polyethylene and aluminum, high density polyethylene, etc..

Permissiveness is the polarization capability of each material; not all materials are polarized to the same intensity.

Permisividad de los materialesCapacitive water softeners installed under identical conditions but in different installations (copper pipe and PVC pipe) will not have the same performance. This is one of the main reasons why capacitive effect systems have a random performance. This is the main reason why these products do not convince the professionals and installers of sanitary hot water.

 2. Random performance due to tube thickness

Another factor influencing the performance is the thickness of the tube. A copper pipe and a high pressure PVC pipe are not the same thickness and affect the treatment differently.

Espesor de las tuberías

3. Random performance due to coatings

Coatings such as paints or biofilms inside the tubes also affect polarization and performance.


4. Random performance due to incorrect installation

In addition, the mounting of the cables or antennas on the pipes depends on the installer. If the antennas are mounted incorrectly there will be insufficient effect.

Instalación incorrecta de un sistema antical

5. Random performance due to tube diameter

If the tube diameter changes, treatment exposure times can be reduced, as the cables will not wind up in the same way depending on the tube diameter. The larger the diameter, the shorter the exposure time.

Diámetro de las tuberías

All these factors cause the capacitive effect system to produce random yields, depending greatly on the support and the type of installation.


Dropson electronic water softener, new generation anti-scaling system

Cálculo profesional del sistema antical Dropson

Dropson has developed a very effective proprietary technology, (EMI – Electro Magnetic Impact), that takes into account all these factors.

It is not based on the capacitive effect and offers numerous advantages.

Comparativa entre descalcificador Dropson y sistemas capacitivos

 1. Factory calibrated Dropson water softener

The efficiency of capacitive effect systems varies randomly depending on the tube material and other factors such as diameter, thickness or coating.

The Dropson system, on the other hand, does not depend on the pipe, but each treatment cell is factory calibrated for flow rate (m³/h) and water hardness (ºf). Therefore, the Dropson electronic water softener is more efficient.

 2. Reproducible result with Dropson’s EMI technology

Dropson does not use the capacitive effect system, but the proprietary EMI (Electro Magnetic Impact) technology. EMI technology offers exceptional performance because each treatment cell is calibrated at the factory with great precision, adapting to a flow curve and specific hardness scale to each model. The result of the treatment is therefore reproducible.

On the other hand, capacitive effect systems do not have a treatment cell, as it is the same tube where the antennas are installed, so with this system the result is not reproducible.

 3. Professional sizing method

In spite of being a determining factor, the commercials of capacitive effect systems do not take into account any calculation or sizing according to the current regulations. They simply recommend a model depending on the diameter of the tube.

On the other hand, Dropson technology integrates a calculation and sizing software that allows the selection of the devices adapted to the needs and applications. The calculation takes into account the application flow rate, water hardness and type of application according to HS4 guidelines.

Software de cálculo Dropson

 4. Dropson’s online support system and multi-platform service

At Dropson we offer an online technical support system and use new technologies to help our customers find the right solution to their problems, even in real time. The service is multiplatform, as it works for PC, tablet, Smartphone and multi-user. We can support the user with technical advice, after-sales service, monitoring and maintenance. For example, a customer can connect with the installer and the service team at the same time using this application.

5. Dropson electronic water softener for easy installation

The capacitive effect system does not require any specific installation. The customer can even buy it on the Internet and install it himself, as it consists of some cables rolled up to the pipes. Dropson needs an installer and an electrical connection.

Como preconizan los profesionales del tratamiento de agua, es imprescindible en todos los casos la instalación de un filtro de sedimentos. El rendimiento de los sistemas de tratamientos físicos, tanto con la tecnología capacitiva como con la tecnología EMI de Dropson, así como los descalcificadores tradicionales de sal, se ve afectado por los sedimentos y partículas orgánicas que se encuentran en el agua.

As recommended by water treatment professionals, the installation of a sediment filter is essential in all cases. The performance of physical treatment systems, with Dropson’s capacitive and EMI technology, as well as traditional salt softeners, is affected by sediments and organic particles in the water.

 6. Dropson offers very competitive prices

The prices of the Dropson electronic water softener are equally competitive with those of the capacitive effect system of well-known brands.

 7. Dropson warranty on the domestic and professional range

The warranty level of Dropson systems is very similar to the capacitive effect systems, offering a 5 year warranty on the domestic range and a 10 year warranty on the professional range.


Practical advice

Dropson anti-scale systems are extremely effective in applications as long as they are used within their performance curve.

As with all technologies, it is important to use it in your field of action. It is for this reason that it is essential to carry out a preliminary study.

Do not hesitate to contact our studio, representative or commercial agent to define your needs.

Require that your cold water and hot water application be dimensioned with the Dropson software from S.A.O. (Computer Assisted Selection) according to the Spanish HS4 standard.


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