Best reflector for behind radiators

[Z]

I am doing a 'service' on the GCH system this week drain, flush and inhibit, hoover out of boiler, thermocouple replacement, rel-ag pipes and insulation/ heat reflectors at radiators.

The pipe is copper microbore and copper 15/22mm.

I have the Sheffield Insulations/ Kitsons catalogues but they don't state mu values for many products.

What are the products with best mu values for pipe/tube insulation? What are the products with best mu values for insulating behind radiators?

Cost is not the object.

It doesn't have to be Sheffield or Kitsons, just the best.

[N. Thornton]

Radiators dont radiate, they convect. So foil is surely of little use. Bubble wrap or other insulation does reduce heat loss.

OTOH if youre selling, buyers want to see foil - so the best would be foil lined bubble wrap.

Regards, NT

[Ed Sirett]

The typical emmissivity of even white gloss painted radiators is around

90%+. The heat transfer by radiation is highly dependant on the absolute temperature and emmissivity whilst the heat transfer by convection is still dependant on the temperature difference and the design (fins or not).

I remember reading that for a non-finned model at 75C the transfer by radiation into a room at 20C is somewhere around 1/3 of the total.

The shiny foils helps the insulation keep a little cooler.

[Z]

In article , N. Thornton writes

They don't entirely convect. There is some radiation and conduction as well.

I'm not selling, I just want the best insulation behind the radiators and around the pipes.

[N. Thornton]

Have you looked at solid wall insulation sheets? Preferably something foil lined. That would give you much more thickness than the bubble plastic film type. Names like celotex, kingspan come to mind.

Regards, NT