
What is the best material to use to diffuse heat from upper heating elements in an oven?
My wife got a new bread oven that works great for regular bread but has issues when she’s making something large and tall. The shape of the upper heating elements (green arrow) is visible in what she is baking, in the form of a darker line. I want to get a sheet of metal and install it under the elements to help diffuse the heat more evenly.
My question is, what is the better to use, steel or aluminum? And any specific type? I’m not trying to block the heat, but help it radiate down more evenly.