Superior All Aluminium Solutions for the HVAC&R Industry

Sapa Precision Tubing (PT) is the world leader in supplying Aluminium tubing for heat transfer applications. The tubes as are normally thin walled round tubes either extruded or extruded and drawn or flat multi port extruded tubes for mechanically assembled or brazed heat exchanger applications, respectively. Wall thickness and number of port holes make these tubes and the requirements quite different compared to standard extruded products In the recent years Sapa has made a significant effort to expand the market by entering into the HVAC&R market (Heat, Ventilation, Air Conditioning and Refrigeration) The HVAC&R segment has traditionally and still are been dominated copper tubing but the market is rapidly changing. However, the conversion from Cu to Al as the material of choice poses significant technical challenges or requirements: 1 Competitive/superior tube product quality is needed; 2 Cost efficient and competitive tube manufacturing processes is needed Sapa Precision Tubing together with Sintef and NTNU is leading this development. The aim is to develop all aluminium heat exchanger solutions with superior corrosion resistance as this will represent a significant step change. So far the project has been looking both on tubes for mechanically assembled heat exchangers and brazed heat exchangers. For the first time a Zn coating process for round tubes has been developed. By using a so called SWAAT test which is a very aggressive cyclic corrosion test with synthetic sea water, we have been able to improve the corrosion resistance of standard 3003 tube which in itself has a poor corrosion resistance. While standard blank or uncoated 3003 round tube with a wall thickness of 0.6 mm fails after 15 days Zn coated according to our process will last ~40 days. Thus, we have an improvement of 300-500 percent. Further improvements are now ongoing in terms of developing a new coating application process. A pilot line has been started up (June 2016) an initial trials looks very promising. The achievements so far has resulted in a significant interest from the market. Regular production of 100 metric tons of Zn coated round tube per month is now being supplied. qualification/implementation is already ongoing with other customers. This is all representing new volume and new business for Precision Tubing. The plan is now to approach new customers with the material from the pilot line in the fall of 2016

Hydro Aluminium Precision Tubing (PT) is the world leader in supplying thin walled extruded tubing in Aluminium. Wall thickness and number of port holes make these tubes and the requirements quite different compared to standard extruded products. The main market today is the automotive industry. In an effort to expand the HVAC&R market (Heat, Ventilation, Air Conditioning and Refrigeration) is identified as a huge business potential by Hydro. The HVAC&R segment is today dominated by Copper tubing. It is t he intention of Hydro to enter into this market and replace Copper with Aluminium. The conversion from Cu to Al as the material of choice poses significant technical challenges: 1 Competitive/superior tube product quality; 2 Cost efficient and competi tive tube manufacturing processes HAPT is leading this development, but more fundamental research is needed. The major innovative step in this project is to use the strength of Hydro as a fully integrated aluminium company together with the fundamental research capabilities at SINTEF and NTNU to develop all aluminium heat exchanger solutions with superior corrosion resistance as this will represent a significant step change. The required durability and overall corrosion resistance will be obtained by modification of the external surface of the aluminium tubes without reducing the thermal performance and the brazeability of the heat exchanger system. Compared to the current automotive requirements, the HVAC&R aluminium heat exchanger system has to be improved by a factor 5 to 10 in terms of corrosion resistance. Special attention will therefore be given to fundamental R&D activity in the field of: 1. In line/continuous tube surface layer formation/coating with additional corrosion protection 2.Tube alloys with superior corrosion resistance of the tube core which at the same time are compatible with the surface coating and the heat exchanger manufacturing process.