This can actually be beneficial if your router is right at the corner of your house. The foil acts as a reflector for some of the radiation that would’ve been wasted, and thus improves the signal quality within your house.
To actually be beneficial as a reflector, the foil would need to be a specific distance from the antenna, which should be a certain fraction of the wavelength. Source: I used to make parabolic reflectors out of milk cartons about twenty years ago.
This can actually be beneficial if your router is right at the corner of your house. The foil acts as a reflector for some of the radiation that would’ve been wasted, and thus improves the signal quality within your house.
To actually be beneficial as a reflector, the foil would need to be a specific distance from the antenna, which should be a certain fraction of the wavelength. Source: I used to make parabolic reflectors out of milk cartons about twenty years ago.
This is basic interference physics.
I am 80% sure this is a net loss with modern mu-mimo radios, and it will absolutely trash your phy rate