Air ducts and siding made of metal.
Does emf radiation penatrate metal siding.
Electromagnetic radiation can be blocked by any conducting material as the free electrons moving in the material adjust to neutralize the field see wikipedia faraday cage or faraday shield.
We are simply showing that skin is a good absorber of microwave radiation and that very little of ambient level microwaves.
Radio frequency radiation is blocked by many materials.
Another common material for constructing homes and commercial properties is brick.
Rf and microwave emf radiation travel in straight lines.
Metal is fantastic for shielding purposes.
Frequently asked questions about electromagnetic shielding.
Just ask anyone that has put a metal roof on their home and tries to get a cell phone signal.
They prevent beneficial energies coming from outside from entering the home.
Therefore you are only protected if there is a material capable of blocking the radiation directly between you and the source of the radiation.
Copper conducts best but aluminum almost as well and steel a little less.
A thick brick wall will stop most of it a metal sheet will stop it completely.
However you do need to remember that although aluminum does block emf radiation it does not absorb it.
Does brick block emf.
The same kind of problems can happen with metallic shielding if not installed carefully.
An ideal faraday cage is enclosed in metal conductive material on all 6 sides including the floor.
The tests used one to three bricks and the results show that bricks were less effective in blocking emfs at a lower frequency.
A 95 enclosure will still allow electro magnetic radiation to get in provided that the opening is larger than the wavelength of the radiation.
This can cause high levels of electric and magnetic radiation in a house possibly even shocking the people living there.
Aluminum foil and ordinary aluminum window screens make good radiation shields.
I suspect they are effective but there are a great many other benefits to metal roofing here.
Of course more intense doses such as putting a cellphone right up to your head will cause the radiation to penetrate deeper.
Nothing blocks low frequency emf.
There are more subtle reasons for not having metal roofing or siding particularly aluminum siding.
It is defined as the depth at which the intensity of the radiation inside the material falls to 1 e about 37 of its original value at or more properly just beneath the surface.
Metals do have an odor to them especially raw plates of steel and aluminum.
It is very difficult to isolate all metal electrical boxes from the metal siding but if that can be successfully done then it is not a problem from an emf standpoint.
