Hi all I'm doing a project for energy efficient buildings with thermal insulation.(Just a leisure project and im not technically that strong!) This is about thermal radiation shielding. My understanding is that Aluminium has higher reflectivity (Hence lower emissivity ) so that it will reflect all the heat due to radiation to the source itself. Is there any other property for aluminium that makes it a radiation shield? Or can I use a steel sheet with aluminium painting to achieve the same effect.(Though Weight will be more but cost will be less).