Embodied energies. Window frames are made from extruded aluminum. It is argued that making them instead from extruded PVC would be more environmentally friendly (meaning that less embodied energy is...

Embodied energies. Window frames are made from extruded aluminum. It is argued that making them instead from extruded PVC would be more environmentally friendly (meaning that less embodied energy is involved). If the section shape and thickness of the aluminum and the PVC windows are the same, and both are made from virgin material, is the claim justified? You will find embodied energies and densities for the two materials in the data sheets of Chapter 15. Use the mean values of the ranges given there.