Steam Pipe Insulation versus Asbestos air cell insulation

Rom

Good day.  I am redoing my basement and my steam heat pipes are exposed.  Some of the asbestos aircell insulation is gone.  I would like to replace it with a safer fiberglass pipe insulation.  I have been trying to find out the r value of the existing asbestos aircell pipe wrap material (with no luck).  I am trying to see what thickness fiberglass pipe insulation I should put back in place of the asbestos.  Also, do I need to insulate the returns as well.

Brad White

Regardless

of what the asbestos gave you, the appropriate size for steam piping would be 1.5" thickness for all piping up to 2" size. Over 2" and up to 4", use 2" thickness insulation. That is from ASHRAE 90.1 as a model energy code used my many but not all jurisdictions.



That said, as a practical matter knowing what people tend to do in the privacy of their own homes, use not less than 1" thickness. Forget the 1/2" stuff from the home stores. But if you can, do use the code thicknesses at least for the near-boiler piping and include the fittings.



I would also insulate the returns. This helps preserve them long-term and of course prevents contact burns. But the low-hanging fruit: Header, supply mains, then runout branches and risers, then fittings. Once you get that done, keep going on the returns.



My $0.02

Brad

Roma

thanks for your info

I just re did all the pipes with the 2 inch and 1.5 inch fieberglass pipe wrap and zeston fittings for the tees.  Seems to be keeping all the heat in the pipes as the basement is considerably cooler as it used to be the hottest part of my home.

Brad White

That insulation should also cause

a more rapid heating of your radiators and quiet down any banging you had due to collapsing steam in transit. Nice weekend project and I am glad you spent more for the thicker stuff. You can sleep well on that decision.