Working Principe – Simple, Non-Technical Explanation
The working principle of the magnetic DPC can be summarized in a nutshell as follows:
Water molecules (both vapors and liquid moisture) bond to wall surfaces due to surface charges - tiny electrostatic charges on the surface. Surface charges vary in time, they depend on the intensity of magnetic fields in the building. Stronger magnetic fields charge the wall fabric up, leading to higher surface charges and stronger capillary bonding. Weaker magnetic fields do the opposite, resulting in lower surface charges and less bonding.
The magnetic DPC is an electronic device that is precisely tuned on to absorb certain magnetic fields in the building which contribute to capillary bonding, channeling their energy into the ground via an earthing connection. This results in weaker surface charges, less capillary bonding so the wall fabric is able to breathe better, evaporating out the moisture accumulated in the fabric for several decades. resulting in dry walls.
Working Principle – A More Technical Explanation
In the lower part of the walls (under 1 m) the dominating force that primarily determines the condition of a wall is soil evaporation. Water vapors from the ground from under the walls evaporate upwards into the porous wall fabric, leading over time to a gradual moisture accumulation. The main wetting mechanism near the ground is vapor movement, not liquid capillary action as previously thought, as walls are built onto the damp soil and not on liquid water (perhaps except Venice).
Water vapors from the ground do not “float through” the wall – by entering at the base and leaving through the sides – even if a wall fabric is fully breathable (e.g. bare bricks with lime) with no moisture barriers present. Instead, water vapor molecules are attracted to capillary surfaces due to surface charges and start accumulating.
Capillary Surface Charges
Surface charges are tiny electrical charges (voltages) on the surface of capillaries. These charges attract the flying vapor molecules electrostatically, which over time lead to moisture accumulation in the masonry, initially on the surface then later in depth, ultimately leading to the appearance of liquid moisture and capillary action inside the capillaries. The liquification of vapors in the capillaries does not occur because of condensation (temperature differences) but because the base of a wall is always vapor saturated from the ongoing 24/7 soil evaporation.
Magnetic Fields can Alter Surface Charges & Capillary Bonding
Surface charges, small electrical charges on the surface of capillaries, are not fixed, but they vary based on a number of factors, one of them being the electro/magnetic fields present in the building. Hydrogen ions (which are part of every water molecule) have a very interesting property: they spin around their own axis generating their own magnetic field. As a result, each hydrogen ion (or proton) acts as a tiny magnet, which can be individually influenced and re-oriented by external magnetic fields:
- Higher external magnetic fields better align these tiny "hydrogen magnets", resulting in stronger surface charges, resulting in a better bonding of water molecules onto capillary surfaces.
- Lower magnetic fields relax and randomize the orientation of "hydrogen magnets", resulting in lower surface charges and weaker bonding of water molecules to capillary surfaces.
Reducing the intensity of magnetic fields in the building leads to decreased surface charges and less capillary bonding of both vapors and liquid moisture. This is what the magnetic DPC fundamentally does.
The Role of the Magnetic DPC
The magnetic DPC is a lampshade-looking electronic system, usually hanging from the ceiling, a combination of electric circuits enclosed in a case, that selectively absorbs certain magnetic fields (frequencies) from the building that contribute to the charging of capillary surfaces, which over time leads to the wetting of the wall fabric.
The magnetic DPC’s internal circuitry absorbs some of these fields, channeling their energy down to the ground through an earthing connection.
The energy that flows from the DPC system to the ground can be visualized as a small earthing current (red), which is shown below in comparison to the magnetic field variations in the room (orange).
The Magnetic DPC Improves Breathability
Leaving everything unchanged in the building (heating, ventilation, no additional repair works etc.) just by installing a magnetic DPC seem to make a significant difference to the moisture content of the walls. When the wall fabric is charged less, water molecules bond less, they can easier evaporate from capillary surfaces including the long-term accumulated moisture, eventually leaving the wall fabric dry.
We could also say that stronger surface charges reduce the extent of natural evaporation, leading to moisture accumulation under the surface. By reducing the surface charges, the magnetic DPC makes the wall fabric more breathable, allowing more moisture to evaporate – even moisture accumulated long-term – and does this in a non-invasive way.
Once the DPC system is installed in a building, the incoming moisture from the soil can evaporate freely without accumulating, keeping the wall fabric dry from that point on.
Research Data – Dehydration Effect
The dehydration effect can be monitored through an array of micro-sensors – installed in the soil, in depth and the surface as well as the environment – monitoring the distribution and movement of moisture through the wall fabric.
Before the installation of the DPC system in the building, the moisture content of the walls was slowly but consistently increasing.
Once the DPC system has been installed in the building, things started changing. The first signs of change have been observed a few days later, the wall voltages which follow humidity changes closely, started changing about 2 days later in the mortar, then about 10 days later in the bricks. (Graph 1)
As explained earlier, decreasing voltages mean wetting (more liquid moisture in the walls), increasing voltages mean drying (more vapors in the walls).
Looking at the 6-weekly trend (Graph 2) following the installation of the magnetic DPC, the changes in the wall become more pronounced despite of the rain. Wall voltages (red) keep increasing, while humidity inside the wall (green) keeps dropping. The automatic trend lines show this clearly.
Here is the official rainfall data from the weather archives comparing Summer 2021 with 2020.
July 2021 was quite a rainy summer, significantly wetter than 2020. July 2021 was also rainier than previous month, June. Despite all of that rain, once the DPC system at the end of June has been installed in the building, the wall fabric started drying out.
Our own rainwater sensors (grey) follow closely the official rainfall data from the weather archives.
Internal Construction - The Circuitry
How can the magnetic DPC absorb or decrease magnetic fields and reduce their effect onto the walls? Here are some basic technical details about its construction.
Each DPC unit is comprised of the following three main modules:
- Energy Intake Module: responsible for the collection of the electro/magnetic energy from the environment using a built-in aerial circuit (spiral antenna), covering a very wide frequency band. This antenna collects everything from the environment, which is then transferred through a hard wired connection in the center to the electronic filtering module located under it.
- Electronic Filtering Module: is a network of very precisely tuned electronic filters (band-pass filters) realized on one or more circuit boards, responsible for the electronic filtering of those magnetic frequencies that contribute to capillary action. These frequencies are then transferred to the ground using the earthing wire attached to the case, leaving everything else (Wi-Fi, mobile signal etc.) unaffected.
- The case: the case is permeable to magnetic fields, having both a functional and protective role. The case has an earthing wire connected that is electrically connected to the ground.
The unit is not powered, it does not need to be powered. The power is in the environment in form of magnetic fields that increase the surface charges and keep the wall fabric in a charged-up state. We are trying to "un-power" the walls from the surrounding environment to reduce or stop the ongoing charging.
For more technical details on the system click below to expand / collapse the yellow box.
Here are some more technical details for engineers or anyone interested.
1. Energy Intake Module
The main role of the energy intake circuit is to collect energy from the environment. This is done by using passive (non-powered) spiral antennas.
Antennas (or aerials) are fundamentally energy converters which convert electromagnetic waves into electrical voltages and currents. In its simplest form, an antenna is a piece of conductive wire (copper or aluminium) in which changing ambient fields (E) induce a voltage (V) or current (I) through electromagnetic induction.
The antennas used in our magnetic DPC system are three-arm spiral antennas. Spiral antennas are special type of antennas invented in the mid-1950s, by wrapping the arms of a simple antenna around each other to form a spiral. This resulted in a very wide bandwidth antenna with a flat, compact construction, widely used today in the defence and communication industry in military aircrafts, GPS receivers, satellite communications networks etc.
The spiral antenna construction allows the system to collect as much energy as possible from the environment on a wide frequency band, transferring that energy through a hard-wired connection in the center to the lower filtering module.
2. Electronic Filtering Module
Research has shown that certain frequencies of the surrounding electric and magnetic fields are especially capable of affecting the movement of water and its bonding to wall capillaries. Water molecules being polar in nature (with one positive and one negative side), are susceptible to external fields. By eliminating certain frequencies, one can cancel the osmotic pumping effect responsible for rising damp – which is the role of the filtering module.
The electronic filtering module is a network of precisely tuned LC band-pass filters, realized with two oppositely wound spiral antennas placed on the opposite side of a printed circuit board (PCB). Their fields intersect, forming a complex inductive-capacitive (LC) network. Due to its technical complexity, we are not going to go into further details of the filtering mechanism – the important point is that certain frequencies are filtered out and their energy absorbed from the frequency spectrum - thus eliminating the key frequencies that actively contribute to the formation of rising damp.
Here is a demonstration of the practical filtering capability of the filtering network, shown on the screen of a spectrum analyzer in the research lab:
The filtered out frequencies show up above as high vertical peaks on the instrument's screen, in comparison to the rest of the frequency spectrum (horizontal base line at the bottom).
3. The Case
The case is permeable to magnetic fields and it plays an active role in the functioning of the device. It is a passive cavity resonator (or microwave cavity resonator) that further assists with the filtering and suppression of certain frequencies, making the unit perform better.
The case works similar to the sound box of a musical instrument or an organ pipe, reinforcing certain standing waves in the cavity, acting as a band-pass filter, allowing certain frequencies to pass while blocking others.
Here are some photos of our smaller DPC systems showing their internal construction. Larger units are more complex with additional circuits / components, but their overall working principle is the same.
Finally, here are a few of our UK installations showing various units fitted in different buildings.
- Moisture from the ground evaporates into the wall fabric, gradually wetting the capillaries through combined vapor and liquid transport.
- Surface charges are small electrical charges on the surface of capillaries. Moisture bonds to capillary surfaces due to these surface charges.
- Hydrogen ions have their own magnetic field, their orientation determines the bonding strength of water molecules to capillary surfaces. This can be influenced by external magnetic fields.
- Stronger magnetic fields align the hydrogen magnetic vectors resulting in increased surface charges, making water bond to capillary surfaces stronger. Weaker magnetic fields in the building do the opposite, they randomize and relax the hydrogen magnetic vectors, resulting in lower surface charges that make water molecules bond less to capillary surfaces.
- The magnetic DPC reduces the capillary surface charges by absorbing certain magnetic fields (frequencies) that contribute to the charging of capillary surfaces, by channeling their energy to the ground through an earthing connection. The reduced surface charges make the wall fabric more breathable, allowing more moisture to evaporate – even moisture accumulated long-term.
- Magnetic DPCs offer a non-invasive permanent solution to the problem of rising damp, which is one of the leading causes behind the decay of old buildings, worldwide.1Franzoni, Elisa. (2014). Rising damp removal from historical masonries: A still open challenge. Construction and Building Materials. 54. 123-136.
|1||Franzoni, Elisa. (2014). Rising damp removal from historical masonries: A still open challenge. Construction and Building Materials. 54. 123-136.|