Common Wisdom or Fake News?
IAQ and EMF meanderings
I was recently approached about a web site (eiwellspring, that “caters” to the environmentally sensitive) that suggests that “twisting” Romex wire “will reduce EMFs.”
Romex is a type of wire covered (insulated) with a plastic cover preventing direct human contact and possibly shock / death. However, the plastic offers no obstacle to the passage of Alternating Electric Fields. Twisting said wire, as they suggest “using a drill,” simply makes a twisted electric field, but does not reduce it. So that web site is blowing smoke, their pontification rings hollow, and does a disservice to those having to use up valuable time to “unlearn” clients, to subsequently really help them.
Wire twisting, for what it’s worth, is used in data cables to reduce their being impacted by strong EM fields. These cables usually use pulsed DC, of perhaps 24 V to convey information, and progressively have more twist per inch, going from Cat 3 (Category 3), to Cat 4, to Cat 5, etc. They are technically designated UTP (Unshielded Twisted Pair) and are fairly inexpensive. They are called Ethernet cables, and used in LANs (Local Area Networks).
So then others come along and claim that you need to use Shielded data cables, “STP” for Shielded Twisted Pair (with me so far?), neglecting the reality that the electric field from 120 V is the primary irritant, that also acts as carrier for any higher frequency content.
Computer power cables are available for about $4 as Shielded. These can be used as standardized fare for printers, displays, chargers, etc., and reduce Electric field emissions by about 98%, and are most beneficial for those spending many hours in a business / office environment.
Another approached me about the PLC (Power Line Carrier) used for high speed protective signaling used on bulk Power Transmission lines (typically 200,000V and higher), as being “powerful.”
I pointed out that such signaling is minuscule compared to the voltage on these lines (typically less than 0.1%), and high enough in frequency (50,000 to 250,000 Hz) that it is beyond human interaction realm. If you are in a position to detect this signaling, you will have to work Very hard, to suppress the 60 Hz component, which is an irritant in and of itself. So those claiming that PLC is bad for you are also blowing smoke, because if you are in a position to be subject to them, you are Very close to a high voltage power line, if not under it (as I saw in an American Indian reservation).
While these are “notch” frequencies, that is, pinpoint accurate and very stable, what is more worrisome is broadband electrical noise typical of cracked insulators on neighborhood aerial power distribution lines operating anywhere from 2300 to 7200 V. Similarly for rusted metal contacts available on multi-bell insulators that wiggle with the wind. These produce a “sputtering” noise detectable from a few kHz to several hundred kHz. These can use the power line as a conduit, for miles.
In one case I investigated, the clients complained of radio noise, despite all their wiring being armored (and by design unable to “radiate” electric fields).
Peculiarly, contemporary electronics can do the same thing on a smaller scale.
A client had an electrician recently install fluorescent lamps in his garage. The electrician lodged the complaint, because he did not know the cause. While modern electronics can produce copious levels of Amplitude noise, the device impacted was the FM radio (around 100 MHz), which by design block out amplitude noise. Bringing along a spare FM radio (don’t leave home without it), and turning off every breaker but one, the noise was still present. Turning off the newly installed fluorescent lighting, the noise vanished.
Another client complained of noise on her AM radio (around 1 MHz). Driving around her home I could not find the culprit. Knocking on her door, I presented myself and asked to investigate indoors. I found a room with a “dimly lit” desk lamp, turned it off, and the noise vanished. The source was a common fluorescent lamp near end-of-life, whose circuit was trying to keep it alive.
A dimmer switch, or most digital devices can produce the same thing.
Along the lines of this “electrical noise,” anything using Current / Power non-linearly will produce harmonics, or echoes of the fundamental frequency, in our case 60 Hz. The strongest echoes / Harmonics occur closest to 60 Hz, and progressively reduce in intensity with higher frequency. These harmonics distort the voltage waveform to some extent, and beyond an “acceptable” level of distortion, devices begin to dysfunction. Justifiably, a very concerned entity is your local electric utility, because if they permit distortion beyond that certain threshold, and devices begin to fail, they will be held responsible. Accordingly, they employ an IEEE standard to define distortion levels, and beyond that level they can shut you down. So large customers have in-house power conditioning systems that make them look like smooth movers to the utility, and neighboring users. Unfortunately, these systems have no residential parallel. Because the harmonics closest to 60 Hz are those most energetic, and those that can cause the worst distortion, utilities are mostly concerned with harmonics below about 2 kHz, or 2000 Hz, that being near the 33rd harmonic.
But there being a few enterprising individuals, they suspected they could make some money off this distortion, and call it “dirt,” with the implication they have something to sell you that will “clean it up.” Enter the “dirty electricity filter.” That was around 15 to 20 years ago. Now there are about 6 or so vendors with variants of filters and the level of dirt they will clean up. They are all blowing smoke. But some people who should know better, have bought into them, simplistically suggesting them as “the solution,” when in fact they are anything but.
These consumer-grade filters, for lack of better descriptor, are a 1) combination of capacitance to short out higher frequency voltage transients, a 2) resistance to quickly drop the charge, so humans can’t stupidly unplug one, and test their tongue with one, and 3) because of the way the capacitors are manufactured, inductance. This combination makes them complex electrical devices that introduce harmonics in and of themselves, and resonant devices at some common frequency based on design, and invitation to ignition. Conveniently, however, these vendors produced meters that show a decrease in number (of whatever entity they measure) that decreases when one of these devices is plugged in. So they are an easy sell.
So these different vendors are heavily competing to outdo each other and capture an uniformed public’s monies, with consultants considering which is the best, for whatever they do. A wild goose chase, followed by gullible and uninformed “consultants” claiming to be experts.
On air quality, it’s common practice to install HVAC units in the basement. It’s also common practice to install air ducts in these basements to condition the upper floors, but not the basement. The result is 1) lack of any air exchange in the basement, 2) lack of dehumidification in the basement, and 3) gathering of dirt in the basement. These three factors combine to make basements the dungeon where you keep the lion(s), and throw the kids into, when they’re bad.
Most of the heaters for these HVACs are open-combustion. They suck indoor air that you’ve paid to heat, and throw it out. Love those dollars going up the chimney. Replacement air must come from somewhere. Usually the attic, and the holes in the wall headers for wires to travel through. Put your hand next to an outlet, next time your heater is on, if you feel cold air rushing in, you’re witnessing the very process just described.
In one instance long ago, a builder erected a small bunch of townhouses, condos, concatenated apartments, call them what you will, but each unit’s border walls are the next unit’s also. The roof structure began to fail. The owners called the builder out on this. To do right by them, he offered compensation to each owner, which they eagerly took. The roof did not get fixed, but now the owners were communal owners to a major environmental failure. As each heating system operated, it sucked in air from the attic, and any adjoining space, such as the next apartment’s wall cavities. The failing roof caused mold growth in the attic. The mold growth and enhanced humidity were sucked down (or up) each successive wall, depending on which unit was online, causing mold growth within the walls. Some people began to experience sensitivity to enhanced mold growth. They complained, but now they were also the owners. They got insurance companies involved, which became a shooting match between each owner and each insurer, trying to fix a problem that laggards were uninterested in fixing, when they were given funds, exactly for that purpose.
This last example should be enticement to buy a detached home whenever possible, where you have the greatest control over any environmental variable that may irritate you.
And for skin-warming news during this Holiday season Expert Claims Chinese Army Used Microwave Weapons