Mr. Rawles,
My child is sick. I need to build a Faraday cage to surround my child’s bed. We are in a second floor apartment. Can I use wood and chicken wire?
To create a ground [for the cage], can I: Take an extension cord, tear out the double prong but leave the ground post, cut off the opposite end attach the wires to the wire cage. Would that work?
Thank You, – M.R.
JWR Replies: I will pray for you and your child.
Faraday cages have no positive health effects for humans unless for some very unlikely reason that you live in an area of extreme RF field strength. (Hypothetically, living directly under a 230,000 volt AC high tension power line or right next to a poorly-designed high power microwave broadcast tower with errant side lobes.) The fact is that low level RF (such as the field strengths found in a typical house or apartment residence) has no negative health effects. Because there was cancer one one side of our family, I did some fairly extensive research on this subject. There have been many very expensive and extensive studies conducted on low level RF and they have found essential NO correlation to incidents of cancer, or other diseases. NONE! A variety of home electronics such as cordless phones, cellular phones, microwave ovens, CB radios, and wireless baby monitors have all been studied by reputable scientific and medical organizations. But the study results have all been negative of inconclusive. By the way, what used to be the biggest emitters in American homes–cathode ray tube (CRT) televisions and computer monitors–are rapidly becoming extinct, as they are being replaced by relatively low-mission flat panel displays. But even CRTs were fairly safe unless you sat within a few feet of them, and it is noteworthy that the greatest risk was for someone directly behind them.
Now, if it is electronics that you want to protect with a Faraday cage: Chicken wire will stop many radio waves but has has apertures that are far too large to stop microwaves. (Look at the size of the fine mesh built into the transparent door of a microwave oven!) EMP is very high energy and has frequency components in a very broad range. So a solid metal structure is best. Copper is ideal, but expensive. Galvanized steel will suffice. A steel trash can works fine. You can supplement the seal of the lid by placing a thin fuzz of stainless steel wool all around the lip before you clamp down the lid.)
And BTW, grounding actually hurts the ability of a Faraday cage to stop EMP, because a grounding cable can itself form an unintentional antenna. The general rule is: For lightning protection, do use a grounding cable, but for EMP protection, do not.
If your child is sick, then take him or her to see a qualified medical doctor!