I'm trying to decide whether or not it would be beneficial to insulate the black pipe, or at least the hotter outgoing pipe from the furnace, in order to force the heat to the radiators more quickly and decrease the firing cycle. I live in an old 3 story row house with 12 old free standing cast iron radiators which are connected to a 100,000 BTU natural gas furnace in the basement. The heated water travels over a vast network of black pipe in the basement ceiling through pipe diameters ranging from 2.3" OD to roughly 1" OD. Given the large volume of water in the basement pipes alone, I'm thinking it would be wise to block the heat with perhaps fiberglass, foam tubes or some other material. The temp in the basement is often about the same as the first floor in the winter!
Would insulation work well in this situation, and, if so, what would be the best type and R value for the job? Thank you!