The zero-house
This section presents constructional and electrotechnical means, aimed at EMF exposure reduction in buildings.
The EMF reducing constructional and technical means can be implemented when
- desigining and constructing a new building,
- renovation an existing building,
- refitting electrotechnical installations.
Theoretically, this allows the construction of a zero-emission house. The zero-house is characterized by an electroclimate that is close to nature, where the manmade components of the electromagnetic field have been brought down close to zero.
Achieving zero-house conditions requires controlling the entire electromagnetic spectrum, including:
- static,
- low frequency,
- intermediate frequency and
- radiofrequency electromagnetic fields.
Both electric and magnetic fields need to accounted with except to the radiofrequency fields, where these are considered together as one field. Zero-house concept requires that appropriate countermeasures are applied, where needed. Sources of electromagnetic fields both inside and outside the house must be taken into account, as sometimes measures are needed and sometimes these are not needed.
The zero-house action plan includes the following steps:
- Measurement and assessment of electromagnetic fields in the outdoor environment, determination on EMF components, their characteristics and the source of origin.
- Determination of shielding/absorbtion measures based on the step above.
- Planning and if possible, measurements of indoor EMF sources.
- Determination of exposure mitigation measures based on the step above. Measures usually include selection of electrical equipment/infrastructure, repositioning the source device, using technical means to reduce the field, e.g. by shielding.
- Carrying out mitigation measures and determining the effectiveness of such by measuring the leftover EMF levels. Improving mitigation measures if necessary.
Reducing electromagnetic fields by constructional and technical means
Table 1 below summarizes the constructional and technical means to mitigate the EMF exposure. Implementation is expressed as Ease of implementation when renovating (1-very easy … 5-significant retrofitting needed).
| EMF type | EMF source | Can be mitigated with | Implementation easiness |
|---|---|---|---|
| power freq. EF | house electrical wiring | minimizing the amount of electrical wires, including lighting fixtures, building fewer wiring paths | 5 |
| power freq. EF | house electrical wiring | installing demand-switch (switchbox) | 1 |
| power freq. EF | house electrical wiring | installing relay switch (switchbox) | 3 |
| power freq. EF | house electrical wiring | installing shielded electrical wiring instead of regular unshielded power wires | 5 |
| power freq. EF | house electrical wiring and building’s metal construction elements | grounding metal constructions within the concrete | 5 |
| power freq. EF | house electrical wiring, power cords, electrical devices housings | using three-wire electrical cabling instead of two-wire cables | 5 |
| power freq. EF | network router/switch, Ethernet wiring and connected devices | good quality router/switch; shielded Ethernet (LAN) cabling whereas shield must be grounded | 4 |
| power freq. EF | metallic constructional elements all over the building | grounding all larger metal elements | 5 |
| power freq. EF | all inbound electric fields e.g. from power lines | screening of walls, grounding walls (if of conductive or semiconductive material) | 3 |
| power freq. EF and MF | electrical heating film below the floor / inside the walls | opt out from electric underfloor heating, use other heating solutions | 5 |
| power freq. MF | house electrical wiring | positioning/relocation of switchbox and electrical wiring | 5 |
| dirty electricity | house electrical wiring | EMI filters installed into the switchbox | 2 |
| dirty electricity | dimmer lighting switches, controllers, electrical wiring, lighting fixtures | On/Off switches instead of dimmer switches and corresponding controllers | 1 |
| dirty electricity | power adapters, electrical wiring, lighting fixtures | opt out from DC lights and use regular power lights instead (120/230V) | 1 |
| dirty electricity | smart meters (PLC type) | installing EMI filter into the switchbox | 1 |
| RF EMF | smart meters (celular network connected) | shielding the space between the smart meter and the building’s residents | 3 |
| RF EMF | all inbound radiofrequency EMF sources from outside the house e.g. neighbour’s powerful WiFi link, cell phone base stations, TV/radio towers etc. | screening of walls and windows (metallic window film or chicken wire) | 4 |
| RF EMF | (same as above) | shielding curtains | 1 |
| RF EMF | inhouse wireless routers, computers w active WiFi, wireless smart devices | switching off WiFi and Bluetooth connections on all devices, using Ethernet (LAN) cabling for internet | 4 |
Demand switch
The basic circuit breaker is replaced in the switchbox with such a circuit breaker which allows current into the wires only when the consumption takes place, i.e. electrical device is switched on. If there is no consumption, then only a low control voltage is let into the wire for the switch to understand when the device is switched on again and power is needed. The advantage of the demand-switch is that when there is no electricity consumption, there is no voltage in the electric wires and thus no electric field emanating from such. When the wires are energized (electrified), an electric field is emitted from all the wires inside the wall – regardless of whether electricity is being consumed or not. This solution has gained some popularity in Europe.
Magnetic switch
An alternative to the above solution is to install a magnetic switch in the room (e.g. bedroom), which can be used to turn off the voltage coming from the electrical panel to that room. The advantage of this solution is the same as the previous one – if there is no electricity in the wires, there is no electric field either. This solution has also gained popularity in Europe.
Installing Interference (EMI) Filters
Many home, office and industrial devices distort the mains electricity by spewing high-frequency noise onto it. These interferences in the electrical wiring can be filtered out to a certain extent by using special filters. Removing this dirty electricity from wiring is a possible, but there is a disagreement in the scientific community, if this is needed. Although dirty electricity from electrical wiring radiates barely measurable EMF levels, some researches believe, these frequencies are very bioactive and should be therefore avoided.
Shielded electrical wiring
In order to reduce electric fields, shielded electric wires can do a great job in constraining this type of field. These can be installed, when building a house or retrofitting an existing building with a new electrical wiring. This measure applies to the use of extension cords, which are also sources of power frequency electric fields. The shielding must be grounded, otherwise it is of little effect. A shielded electrical wire helps in isolating the electric field, but the magnetic field still passes through the shield unimpeded. At the same time, the magnetic field radiates from the electrical wiring only when there is a load (power consuming electric equipment). Usually there are only a few high load devices in the household, so the location of such wires needs careful consideration.
Three-core electrical cabling is a must
Back in the nineties, the electrical wiring of houses was still built with two-core electrical cable. However, a three-core cable (third core for grounding) is necessary to ground the housings of electrical equipment. This yellow-green ground wire is also very helpful in shielding and grounding electromagnetic fields. In modern houses three-core cables are used in wiring. Two-core cable wirings give off a lot of electric fields that is everywhere where the cables go; elevated electric fields extend to at least 1m (3f) from the cables.
Ethernet (LAN) cabling
Sometimes the source for an elevated electric field is an internet router, which passes along the electric field over the whole house via LAN-cables. Years ago I was EMF-checking my cousin’s place. It was a relatively new townhouse with a well made electrical system. However, all the places, where LAN-cable was present, were emanating elevated electric fields. It turned out that a cheap internet router, powered by a poor power adapter, passed along power frequency electric field onto all outgoing LAN-cables. The reason behind such exposure cases is usually a poor electric design, where the router’s manufacturer wanted to save a buck or two and skipped some electronic components. Pay attention to the selection of the router so it would not make the entire LAN-network to radiate electric fields. I have had many routers and switches and less than a half of them are OK. Unfortunately this info is not contained within the user’s manual or other manufacturer’s documentation, and can only be determined by measurements.
Prefer other types of heating to electric underfloor heating
The electrical heating cable inside the floor emits a significant electromagnetic field – both power frequency electric and magnetic fields are generated. This is an unnecessary exposure scenario, which involves relatively high exposures, and which could easily be avoided. I remember asking about this from a seller of such electric heating films. He claimed that their products even have therapeutic effect. Little did he know, that anything that affects the body beneficially, also has the potential for adverse effects – as all depends on the dosage. Also consider, that ungrounded metal water pipe (water heating) may also emit the electric fields.
Grounding all larger metal elements
Building’s metal structures and larger metal surfaces on interior furniture are grounded. Any ungrounded metal parts will collect stray electric fields, create electrostatic charges and/or resonate with other electric fields sources, such as electrical wiring. This measure applies also to metal bed frames and other furniture with metal surfaces. For example, a metal frame bed is placed next to a wall; electric field generated by an electrical cable inside the wall “jumps over” to metal frame, which in turn becomes into a significant exposure source. Some electrosensitive people even ground the springs of spring mattresses, but most prefer foam mattresses, which do not have springs.
Avoid dimmer switches (lighting fixtures)
A switch with adjustable light intensity (dimmer) generates an excessive electromagnetic field (pollution electricity), which radiates from 1) the switch itself, 2) from electrical wiring and 3) from the lighting fixture and the light bulb. Some really bad dimmer switches even pollute the entire house wiring with this dirty electricity. Some high quality and newer types of dimmer switches create less of this dirty electricity. This kind of electromagnetic pollution is not present in ordinary ON/OFF switches.
Avoiding DC lights
Low voltage, DC (direct current) lights (e.g. 12V) work by converting 120/230 Volt AC into 12 Volt DC. Power converter/adapter is needed for that. The conversion takes place through intermediate frequency circuits, which generate dirty electricity. Most such adapters generate an excessive electromagnetic field (pollution electricity) that radiates not only from the adapter, but also from the light fixture and the electrical wires in between. If it is a poor-quality converter, then dirty electricity also spreads into the house’s entire electrical wiring. If the low voltage DC lights are directly powered from a battery or a high quality pure DC voltage converter, then of course, the power is clean and there is no dirty electricity.
Screening of walls
If it is not possible to eliminate the source of the electromagnetic field radiating from the other side of the wall, protective measures need to be considered. Mostly we think of shielding and/or absorbing materials. When constructing a screen, the screen must also be grounded, otherwise it may become a source for power frequency electric field exposure. However, this measure should be a last resort, as the shielded room may become a Faraday gage. The result may do more harm than good, as all the RF fields generated inside the gage will remain there, as these can’t get out. Also, there are many types of natural EMF fields, which are believed to be important to all living organisms. There have been only few studies, that have investigated isolating humans from natural EMFs, but the results suggest that natural EM signals somehow regulate biological functions and are needed for proper functioning of the living organisms.
Use of shielding curtains
Windows are often the main entrance point for radiofrequency fields into the buildings. Even when the wall material successfully blocks most of the field, the windows may provide a conduit and exposure habitants inside. If significantly high radiofrequency EMF (WIFI, mobile communications, radar, etc.) penetrates the windows, metal fabric curtains can block this radiation. However, if there is a gap between the curtain and the wall, a significant part of the microwave will still pass through and enter the room.
Electrical switchbox as far away from people as possible
If the building is under construction or has an electrical system that is being replaced, it is practical to place the electrical switchbox of both the apartment and of the building as far as possible from the places where people stay longer (nurseries, bedrooms, living rooms, studies, resting places etc.). The same principle should also be applied to the electrical wiring plan. Make sure that the cables do not run through the immediate vicinity of where the habitants stay longer time. Most important is to avoid the proximity to sleeping places (beds). All the house current passed through the switchbox, which is accompanied by an equally strong magnetic field.
Metal constructions within the concrete
When building a house, it is worth ensuring that the metal reinforcement is properly grounded (by welding). This applies to reinforcement elements and other metal structures within the concrete everywhere – in the foundation, in the walls and ceilings. Ungrounded metal can become an electric field source.
All the iron within the building creates also static magnetic field anomalies, the health effects of which are less investigated. Based on these research questions, some prefer to avoid excessive amounts of iron near people.
Measurements before and after mitigation measures
Measurement should be carried out:
1) to know how strong is the electromagnetic field, to assess whether and to what extent the afore mentioned measures were successful;
2) after implementing the measures, were all types of fields mitigated – in certain cases, screening may be effective for radiofrequency fields, but low frequency ones still come through.
DISCLAIMER
All the above mentioned changes should be done by a qualified specialist. If you don’t fully understand the recommendations above and are not qualified, consult with a lisenced expert. Inadequate application of the above may not produce the desired results and in certain cases may even be dangerous. The information presented in this website is for scientific research purposes, and only reflects the findings of author’s research.