Shiny paint as an insulator.

Shalom

Something that was brought up in a recent thread reminded me of this:

I remember my grandfather ע״ה always fixing stuff around the house, basically he was his own handyman. One of his "bibles" was a handyman's handbook called something like "First Aid for the Ailing House". In this book, I vaguely remember (it's not around now) where it mentions that you should never paint radiators with reflective paint, because it could cut down the radiated heat by 50%, and if you did, just repainting them with regular house paint should restore them to normal.

If this is true, how come we don't all paint our steam mains with shiny paint as an extra layer of insulation? Something like this for instance. Or you could use something like an automotive engine paint; I bet exhaust manifolds get way hotter than a steam pipe could possibly get at 1 PSI.

KC_Jones

I could be wrong here, but once you cover the pipes with insulation I don't think the paint has an effect anymore. If it's covered with insulation you have effectively stopped or dramatically reduced the radiant and taken the paint out of the equation.

Larry_52

Reflective coatings lower radiation, once the pipe is in contact with something radiation is less of the heat xfr versus conduction. Insulation lowers both the radiant and conductive heat. Painting the surface lowers radiant loss but does not stop conduction to air which causes convection.

bob_46

Try this .......https://heatinghelp.com/heating-museum/does-the-color-of-a-radiator-matter/