LOW EMF COMPUTING
1. There is presently no such thing as a zero EMF monitor or computer, but there are methods to lower their EMF (described below).
2. Turn off all electronic devices at night, and whenever they are not being used.
3. Do not use WiFi or any other wireless devices. Be certain that your computer's Wi-Fi and Bluetooth are turned completely off.
4. When using a laptop, set it to full brightness (see below), and preferably use it on batteries, and not while plugged into the charger. Leave the charger/power supply/power brick unplugged from the wall when you are not charging the batteries. Never use a laptop in your lap, and preferably use it with an external mouse and keyboard. A solid-state hard drive will have less EMF emissions - particularly important in laptops.
5. Avoid switching type power supplies and chargers; substitute the old-fashioned linear type of power supply instead. UPS units (Uninterruptible Power back-up Supplies) include a switching power supply that is on 24/7.
6. Try turning off all computer sound. This may inactivate the sound chip which can be a source of EMF because it utilizes pulse width modulation - a chopping at high frequency (similar to in a switching power supply) in its generation of sound. The most EMF may be generated while displaying streaming video - this data is coming in hundreds of times faster than when simply surfing the net.
7. Distance plus the use of optical cables can be very helpful in reducing EMF exposure.
8. The Apple iMac models are a dangerous choice because the computer itself is integrated into the monitor (they have been the cause of greatly increased sensitivities in two of my clients).
9. Most shielding is not very effective.
10. EMF exposure from more than one device simultaneously is often additive.
11. Terminate your computing session before symptoms accelerate.
12. The (PC/Windows) computer with the lowest EMF may be the fit-PC mini desktop, run on an external 12V battery or a external 12V linear power supply. The EMF and power draw will be lowest if its hard drive is solid state. The website of a US distributor, Red Post, is: http://www.thefitpc.com/. Their "fit-PC3 Low Power" may be a good choice. Talk to Jerry at Red Post; he can configure it any way you want, and can even remove the wi-fi card.
13. A truly low emf monitor probably does not presently exist. I am working on one. SEE: "SOLUTIONS" AT THE BOTTOM OF THIS ARTICLE.
14. A relatively "lower" EMF laptop may be a new HP model because it has an ultra-low voltage, low wattage (17 watt) processor, and is "all-metal": http://shopping.hp.com/en_US/home-office/-/products/Laptops/HP-ENVY/A9D34AV?HP-ENVY-Spectre-XT-Ultrabook-13t-2000&jumpid=re_r11260_evny14_spectre_xt_overview_buy_now_jun12
It has a solid-state hard drive, and an external 65 watt power adapter. It could have less than the usual EMF, or it may have very strong EMF. No one I know of has tried it yet, and neither have I. If you try it, please let me know whether or not it works for you.
There is presently no such thing as a zero EMF monitor or computer. Some are much lower than others, but all radiate EMFs. It is impossible to shield all the emissions (see my article: EMF Scams). Most computer manufacturers are in denial about EMF sensitivity. I don’t think we can expect any (except in some cases inadvertent) help from them for many years.
Everyone who is electrically sensitive has their own particular frequencies that bother them the most - each person is different. Furthermore, there are no criteria that enable one to predict with certainty, on the basis of published specifications, which computers have less emissions. Some EMF meters, or a combination of various EMF and gaussmeters, may give a rough idea, but only as a general and not completely reliable guideline. This is a very complex subject, but in general, some laptops and some netbooks have a better chance of working for people than most towers/desk-top units. Unfortunately it is trial and error: buy only with a money-back return policy. (In the case of Apple this may only be possible if you purchase directly from Apple - their AppleStore - but they do charge a restocking fee. My first all-aluminum 13" late 2008 Apple MacBook 5.1" was not bad; but the 2010 Apple MacBook Pro 15" is reported to have very high EMF.)
People might tolerate a computer at first, and then gradually become sensitized to it with longer use. If you begin to notice symptoms, it would be prudent to terminate your computing session before the symptoms begin to magnify. Take a break for a few hours, and don't turn on your computer again until well after your symptoms have dissipated. If you persist beyond a certain point, then you can be more sensitive for days.
It is best to get a computer that has a power supply that is external, and/or can be battery operated. While operating from batteries, unplug any charger; be sure to leave the charger / power supply / power adapter / power brick / wall-wart unplugged from the wall when you are not charging. Most chargers and most power supplies, either inside computers or stand-alone supplies, are of the "switching power supply" type, which usually generate huge amounts of EMF that is both conducted along wiring and cabling, and also radiate into space. The older, less efficient "linear power supply" type has much less high frequency EMF than the "switching" type. Switching" refers to chopping the power at a very high frequency in order to be able to use a very small transformer to do the voltage conversion. Linear supplies do not chop the power at high frequency and therefore require a larger, heavier and more expensive transformer. This transformer does have a large but only local 60 Hz magnetic field which does not radiate for more than a few feet, whereas the high frequency RF of switching supplies radiates for great distances, both through space and throughout the house on the house wiring. It is very difficult and expensive to effectively filter and shield a switching power supply. The linear supply puts some noise on the powerline, but the amount of this noise is far smaller than what the switching types inject. Any power supply is best plugged into the wall via a good AC line filter. Linear power supplies are still available, and I have successfully replaced many switching-type supplies with linear supplies to significantly lower the EMF of a system, and this requires some custom work. A switching-type supply can alternatively be replaced by a rechargable storage battery followed by a linear voltage regulator.
Use a laptop or monitor screen only at full brightness, since brightness reduction usually brings a dimmer-switching circuit into play which generates much more EMF. When a laptop backlight is set to a lower than full brightness setting, the RF emissions usually increase noticably. For this reason, set the backlight intensity to 100%, and if this is too bright for your eyes, either use sunglasses or put a filter in front of the screen, or just increase room brightness to compensate. This dimmer-switch effect may not be true for all screens, but can be checked out with an AM radio as a RF sensor.
Using an external keyboard and mouse is usually better than keeping your hands directly on the laptop. The old-style mechanical roller-ball mouse or trackball usually has less emissions than the modern optical mice. Keyboards vary widely in their emissions (they all contain their own microprocessors). The Macally IceKey may be better than most. Do not use WiFi or any other wireless devices.
For further EMI reduction, optical fiber cables are available: optical USB to connect keyboard, mouse and even printer to the computer, optical DVI or HDMI for connecting an external monitor or projector and also optical media converters for connecting modems, routers and networks to computers through optical ethernet. These optical links usually consist of a small "upstream" box connected to the computer and powered by the computer through this connection, a small "downstream" box connected to the peripheral device, and optical fiber connecting the two boxes. The fiber connection can be of almost any length, sometimes up to many hundreds of feet. The downstream box requires a power source, often a small 5 Volt supply. Be sure that the setup does not include or require a copper/metal conductor either bundled with the optical fiber or as a separate cable for supplying this downstream power. Manufacturers often sneak in this electrical conductor without clearly telling you, and this results in a connection that can conduct EMF from the computer since it is no longer purely optical fiber. When a stand-alone power supply is included for downstream power, it invariably is an EMF noisy switching supply, and so it should be replaced by either a linear power supply running off of AC power, or by a rechargable storage battery and a linear voltage regulator. I can supply more information on optical cables and power supplies to power them, via telephone consultation.
A solid-state hard drive will have less EMF emissions and will provide a longer battery life than the standard mechanical hard disk drive, and many of the newest laptops and netbooks offer a solid-state drive as an option. This option usually costs more, but the prices are coming down rapidly.
Some persons have tried to use a projector or pocket projector as their monitor so that they can sit farther away than from the usual monitor screen, but unfortunately, all of the projectors I have tried or know about have far stronger (even at a distance) EMFs than an LCD monitor. This is due to the switching power supply necessary to power the lamp, or the pulsing of the LEDs in a projector with a LED source.
LCD screens with LED backlight are usually no better than the old fluorescent backlight as far as EMFs go, because the LEDs are usually pulsed, and their supply is of the switching type.
For a chemically sensitive person, any of the Apple iMac models would be a dangerous choice for the following reason: about one-half of chemically sensitive persons eventually develop electrical sensitivities, especially from sitting near computers for a long time, and the iMac places not only the monitor, but also the computer processor, drive and switching power supply irrevocably only two feet from your face. On the other hand, when the computer is separate from the monitor, you have the option of moving the computer with its power supply further away from you. In general, most EMI emissions decrease with distance much faster than you might expect; the intensity is often inversely proportional to the square of the distance. This means that the intensity at 4 feet can be 1/4 of that at 2 feet, and at 8 feet it can be reduced to 1/16th. Although this is significantly helpful, it is not quite as helpful as it seems, because living cells are logarithmic in their sensitivity (see my discussion of this in part 4.D in my article "EMF Scams"). The longer cables required when a computer is moved further away can increase the overall EMF's, and possibly EMF's perceived, because the longer cables act as better radiating antennas. This is best remedied by using optical cables, but even these can have emissions at their downstream end, where the optical signal gets re-converted to electrical, that may affect some people. But greater distance and the use of optical cables usually end up being the best solution.
Amateur attempts at shielding are usually not very effective. Proper shielding requires a great deal of engineering expertise and experience, and is expensive. Aluminum foil will shield some of the high frequency EMF, but only if it is close to and covers the radiating source completely and also extends beyond the sides of the source.
In general, laptops have lower emissions than desktops, not only because they can be run on their internal batteries, thereby avoiding a main switching power supply, but also because they are highly integrated, compact and more efficient in their use of power. Laptops also avoid the need for an auxiliary back-up power device such as a UPS which are intense generators of EMF because they have a switching power supply that is always running. If you get a laptop, it is probably best to get one with a unibody metal case, which may provide some shielding. A solution (but probably an imperfect one) for an electrically sensitive person could be a relatively low emission netbook or laptop running only on its internal battery, placed at some distance and used together with a wired keyboard and mouse, and with an external monitor if you can find a monitor you are not too sensitive to. The best bet for a monitor would be a model with an external rather than internal power supply, especially if that external switching supply were to be replaced by a linear type of supply.
The additive principle: EMF exposure from more than one device simultaneously is often additive. If you do not feel any EMF effect from a first device when it is on alone, it can nevertheless be increasing your sensitivity to a second device when both devices are on at the same time.
I have had success (much reduced EMF) with a projector I designed and built myself, and with TV's in which I have replaced EMF-noisy switching power supplies with quiet linear-type power supplies, and with portable, battery powered DVD players. I have been modifying LCD's for use as TV's or monitors for others on a custom basis.
Since it is nearly impossible to shield a flat screen monitor to a high degree (and still be able to see the screen easily), I feel that using a shielded projector as a monitor via rear screen projection from a distance is the way to go. I am presently designing a special shield box for a projector. A very low emissions computer that can be used with it, either inside the shield box, or outside of it, is the FitPC-3: http://www.thefitpc.com/ . My shield box will provide a very high degree of shielding of the projector, and I expect that it will be comfortably usable by most persons who are sensitive to their monitors and computers. My tentative timetable: XGA or WXGA projector in shield box (with or without computer) December 2012; very low EMF mouse, December 2013, near-zero EMF keyboard May 2013. Unfortunately it is all quite expensive, but for many of us it is the only way that we can continue to work.
Some people may be able to tolerate a less expensive intermediate solution: a LCD monitor that has a separate power adapter that can be replaced with a linear power supply. In some cases it may be possible to also change the pulsing power that normally supplies an LED backlight to DC, but this requires custom work. Many monitors will still have too much EMF even after changing the power adapter, but a few may be tolerable. It is a crap shoot - no way to predict in advance, although an RF sensor/meter may give some relative indication. I am currently building a hooded partially shielded box with a shielding viewing window for a LCD monitor.
To summarize this intermediate option:
1) LCD monitor selected for lower EMF, having separate power adapter replaced with a linear supply;
2) optionally customizing the power to the backlight, if backlight is LED;
3) optionally putting the monitor inside a shield box with special shielded viewing window;
4) use with a low EMF computer at a distance, such as a fitPC-3 Low Power with an internal solid-state hard drive-SSD and with its wi-fi card removed (talk to Jerry at RedPost: http://www.thefitpc.com/products/fit-pc3-lp , he can configure the computer any way you want) and powered by a linear 12VDC supply);
5) using an optical cable to carry the video signal from the computer to the monitor; I recommend the Rainbow Fish Optical HDMI Professional Cable ( http://www.rainbowfishcorp.com/ ) for which I am a dealer - I can give you the best price;
6) and using a second optical cable such as a fiber-only Opticis Optical USB Cable ( http://industrialcomponent.com/opticis/optusbext.html ) to carry the USB signal from the computer to the keyboard and to an old-fashioned roller ball mouse.