Aluminum coils are considered environmentally friendly for several reasons. They are highly recyclable, with the recycling process requiring significantly less energy compared to producing new aluminum. This reduces greenhouse gas emissions and conserves resources. Additionally, aluminum is a non-toxic material that does not leach harmful substances into the environment. However, the environmental impact also depends on the production process, which can consume energy and generate emissions. Overall, when properly recycled, aluminum coils have a lower environmental footprint than many other materials.