I was watching the movie “Signs” the other day and there is a scene where some of the characters are wearing foil hats to prevent the invading aliens from reading their minds. Sounds crazy doesn’t it? Maybe not… It reminded me of how SCIF barriers are used to block radio frequencies in a wide range of applications.
It is a well-known fact that aluminum is an excellent reflector of radio waves. The use of a conductive material like aluminum to prevent interference from radio waves is known as “shielding.” It is used in many electronic devices, electrical musical instruments, microwaves, medical and laboratory equipment, radio and television broadcast equipment, and more. This shield prevents any radio waves bouncing around in the air from interfering with the proper operation of the given device. This is what the characters in “Signs” were trying to accomplish by wearing the foil hats.
The U.S. Department of Defense uses the same principle to isolate rooms in which classified information is discussed. These rooms are known as Sensitive Compartmented Information Facilities (SCIF), and are designed to prevent surveillance and leakage of sensitive data. Among other things, these rooms are essentially wrapped in foil.
To prove the effectiveness of aluminum to shield radio waves I decided to conduct an experiment. At my desk I get pretty good signal on my cell phone, 4 bars. Even if my phone is in my pocket or in a drawer it always rings. For my experiment I wrapped my phone in SCIF radiant barrier, being sure to fold over all of the edges. Then I called it from a different phone.
This shows how effective SCIF barriers are at blocking radio frequencies. However in order to block these frequencies it is important that a SCIF room is completely sealed to prevent any leakage. I found this to be true because my phone still rang when the foil was not completely folded over.
There is no need to worry if you are adding radiant barrier to your attic. Installing perforated radiant barrier in your attic won’t have an adverse effect on your cell phone reception, provided you have good signal to begin with. The reason is because the signal can still get out of the house through the walls and windows.
This is why SCIF requirements are so stringent; it is extremely important that the entire room is shielded thoroughly to block any radio interference. This would also lead us to the conclusion that a hat of foil really would do little if aliens really were trying to read our thoughts…
To learn more about SCIF barriers and attic foil visit www.ecofoil.com or call 888-349-3645.