Joel --
Good points. In a recent newspaper article in Boulder, CO about a really
bad PV install, the direct grid tie inverter was mounted right on the
outside of the wall from the homeowner's bed. They finally had to have
it moved--mostly because of buzzing, but EMF was a concern too. It was
basically less than a foot from the guy's pillow.
Also, I forgot to mention that there are fairly inexpensive EMF meters
available from the same places that sell DIY shielding materials.
The biggest source of EMF at *my* house is actually the E-Meter
measuring amp-hours. It even interferes with my handheld ham and fire
department radio FM communications on 2 meter.
DAN FINK
Renewable Energy Consultant
Joel Davidson wrote:
Ron,
Electromagnetic fields are produced any time you have current flowing
through wire. They are low frequency waves that drop off rapidly
proportional to the distance from the source. Inverters, transformers,
fluorescent light ballasts, motors, clock radios, power blocks,
microwave ovens, kilowatt hour meters, service panels all emit EMF.
There is no
practical way to block EMF. It passes through almost everything
including walls and even lead. There is no U.S. safety standard for EMF.
Some say 8 milligauss or more is dangerous and 2.5 milligauss or less is
safe.
I went through our home about 10 years ago using a borrowed milligauss
meter (thanks David Katz). Our utility meter service had significant
EMF, but that was not a problem since it is mounted on an outside wall
and there is a closet between the living space and the meter. The EMF
had fallen to below 2 milligauss between the wall and the closet door.
The bedroom clock radio was the second largest EMF source in our home.
Moving the clock 1 foot away from the bed to the other side of the night
stand brought the EMF levels under 2 milligauss. Our SW4048 inverter
emitted a field that fell to a safe level 2 feet from the inverter.
I tell people not to put their bed against the wall where their utility
service panel or inverter is mounted. I also tell them that the Japanese
did a 2 year study of school children riding the Tokyo subway (big EMF
emitter) and found that there was no danger.
Some sounds that most of us take for granted can cause physical
discomfort and even pain. SW4048 and other transformer and electrical
and electronic buzzing can be annoying. Also certain wavelengths and
intensities of light can cause pain and injury.
Joel Davidson
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