Selecting the correct material is vital for thermal efficiency and longevity. Aluminum radiators are preferred for their high thermal conductivity and lightweight properties, making them ideal for modern HVAC systems. Cast iron radiators offer superior heat retention and are best for traditional heating systems, though they have a slower response time. For automotive or heavy machinery, copper-brass radiators provide excellent corrosion resistance and repairability, while aluminum-plastic combinations are the standard for cost-effective, high-performance cooling in modern vehicles.