Heya, id like a little help calculating the efficiency of some steam heat exchangers. They are used in industrial dryers, steam goes through the radiator and then air is blowed to it in order to heat the fabric. Currently my radiators are made from carbon steel tubes and fins, it has 78 flat tubes of 1 ¾” x 64” so if i calculate my area not considering the fins i get: 1 ¾”/12 x 1 ¾”/12 x 64”/12 x 78 = 121 square feet. Im planning on having them made from cooper tubes and aluminum fins due to better availability in my area and better thermal conductivity of those materials. Since the cooper tubes are circular the new design will have 144 tubes of 5/8” x 64” so my new area not considering the fins should be something like this: 144 tubes x 5/8”/12 x 3.1416 x 64”/12= 126 square feet. My questions are basically if those calculations of the area (excluding the fins) are correct and how can i calculate how much more efficient will the cooper radiator be vs the carbon steel radiator in steam usage. I know cooper has a thermal conductivity of around 400 w/(m.k) and carbon steel is around 43 w/(m.k). Should i just multiply that by the area? or how do i proceed? Heres a picture on the actual radiator im using at the moment. https://i.imgur.com/czaSy.jpg Thanks in advance! PS: I have never worked with anything similar to this so pardon my ignorance on the subject.