The old radiators I had was marked on the radiator housing with the vendor who had made them. Those vendors were since long time ago out of business or bought by other vendors. This made information about the old radiators hard to find. I had found a number of very helpful persons in VVS-varuhuset in Malmoe but not even they could help me by finding the old data for the radiators.
However, luckily enough, old things sometimes become modern, so I did find information about newly produced copies of my old radiators. I have to assume the copies are about as good as the originals.
For the copies, the vendor did supply tables about the radiator. I had two types of radiators, the Duplex and the Rex kind. The Duplex radiator had a data description as below:
Power in Watt at delta t