So, I’m trying to build a Faraday cage to enclose my bed. I’m looking at stainless steel fabric or insect screening (uncoated). To keep everything out, do I need to ground the cage?
I could be wrong, but I don’t think so.
ETA, I was wrong, wiki says yes.
OK I’ll bite; WHY are you building a Faraday cage around your bed?
@Joey P, thanks.
@EvilTOJ, to keep my personal space clear during sleep for personal health reasons. To elaborate would take too much time.
I’m pretty sure that you don’t need to ground a tinfoil hat for it to work.
Decided to go with copper instead as I’ve just found it in a woven wire fabric material. You might have seen like a drape kind of thing that you can hang from the ceiling and it encloses the bed… that’s the sort of thing I’m trying to make.
To actually work (as opposed to making you feel like you are doing something), a Faraday cage needs to be completely enclosed - all six sides need to be shielded, and there can be no gaps bigger than the holes in the mesh. They are not easy to make.
I don’t care what Wiki says, you shouldn’t have to ground your Faraday Cage. But most people would, out of general principles.
Having built or repaired several Faraday cages, I can attest that getting a good and complet seal is a real bitch. Bring a radio and cell phone into the cage with you. If you still get a signal, it’s not good enough. Look carefully for tears.
The toughest part is the door. The good Faraday cages use phosphor-bronze spring “fingers” to make a good seal around the edge. Do NOT leave a long straight un-connected slit in your Faraday screen – it will act like an antenna and effectively broadcast into your cage. If you can’t manage a good door with tightly-fittiong edges or those phosphor-bronze fingers, then take some of that copper mesh, tease so,me of the cross-wires from the edge so that you’re left with parallel wires extending an inch or so from each edge, bend these at right angles to the mesh and “weave” them into the surface around the edge of your seal. If you do this around the edge of your door (or in place of a door) you won’t have any large gaps in your Faraday cage.
As others have said, it does not need to be grounded. The principle involved, as discovered by Michael Faraday, is that electricity will flow around the outside of an enclosed box and will leave whatever is inside completely undisturbed. This effect does not rely on a ground being present.
Faraday cages are only effective against electric fields. They do not block magnetic fields. To block a magnetic field, you can use something like a ring ground or a halo ground to shunt the magnetic field’s energy to ground. These do require an earth ground connection.
Faraday cages will block out radio frequency electromagnetic radiation. The frequencies that will be blocked have no known health effect on the human body. Other than psychological, a Faraday cage will have no effect whatsoever on your health.