The problem comes from the large interstitual spaces between the pieces.
Packing peanuts attic insulation.
Air with very small temperature gradients will start to float through the peanut pack and transfer heat from the warm surface to colder zones with little resistance.
New packing peanuts are made from a type of corn starch.
If they get wet they ll dissolve and they re made to be highly biodegradable so they ll break down pretty quickly anyway.
Osborn a former associate editor replies.
We found millions of packing peanuts loose in the attic presumably intended to function as insulation.
Plastic peanuts hold air that helps cushion whatever is being shipped.
Has anyone ever seen this before.
The older kind might work okay.
In a wall cavity they would offer little resistance to air movement so they would be of limited r value.
The very reason why plastic peanuts work well as packing makes them a bad choice for wall insulation.
Most packing peanuts are made of polystyrene.
The r value of polystyrene is about 4 0 per inch.
I m not convinced that it s effective or even safe.
Good insulation works by trapping air.