Refurbishing old single-glaze unmilled alu frame windows from the 1970s is generally said to mean
- caulking gaps to the roof cavity in the architraves so as to cut heat loss from living space to the roof cavity ;
- weatherizing around the edges with e.g. products by Raven;
- adding some sort of pane insulation such as window film by Enerlogic or 30 mm bubble wrap over a thin water film. Been there, done that.
But those alu frames are still conducting heat past any pane insulation and weatherizing out to the cold night air, are they not.
I have read that modern alu frames all have thermal breaks in a sandwich construction to stop that heat loss.
So is there a product e.g. silvered adhesive heat insulation tape that can be stuck to the inside of old alu frames to bring them up to the modern performance level?