Insulation debate

FireDoug

Let me start off with an apology first.  This was probably debated before and may continue on for some time.  I did insulate all of my one pipe steam piping in the basement including mains,return and runs to the rads.  My question is, Do you save fuel with fully insulated piping as opposed to heating the mass of the floor and joists when un-insulated pipes?  The basement was very warm, now its much cooler.  Also for the first time, I'm keeping the t-stat set at 70 degrees 24/7, although this year was a tough one in CT.

Doug

David Nadle

Is the basement inhabited?

I say put the heat where the people are. Insulate.

Roma

INSULATE

I just had my asbestos removed and reinsulated my pipes.  I used fiberglass insulation from idccorp.com.  I used 1.5 inch thick on any pipe up to 2inches in size and 2" thick insulation on any pipe 2.5inches or bigger.  I definetely noticed a huge difference in the basement being much cooler and the pipes staying hotter for almost an hour or so.  The fiberglass insulation is about an rfactor of 4 per inch while the asbestos was about 2 rfactor per inch.  I had my pipes exposed for about 2 days before I reinsullated the pipes.  It was cold weather those 2 days and my boiler seemed to never shut off.  My basement was hot and my house was cold.  This is now reversed since I insulated the pipes.

Brad White

Insulating steam piping does

several wonderful things. The first, as David noted, is that it keeps you from heating a space you do not inhabit. (If you DO want to heat the basement, do it on your terms, not incidental to a boiler running.)



The second but probably most important function is the speed at which your generated steam gets to your radiators. My last steam system (I sold the place in 1983 and wish I knew then what I know now), had bare pipe when I bought it. Cold start to hot radiators was nearly 40 minutes. Once I insulated just the mains and most run-outs that was cut in half.



A third function is a potential one- noise. A bare pipe will collect condensate and generate it at a rate six times faster than a properly insulated pipe. That sudden collapse can cause banging, water hammer, panting (the ebb and flow from vacuum to full to vacuum again).



Use not less than one inch thickness, although model energy codes in most states stipulate 1.5" thickness for up to 2" piping. Do that if you can afford it.



So yes you will save energy but insulation is just one part of an overall strategy.



But unless your basement temperature was a degree higher than your living space, your gain to your floors would be minimal. A very inefficient form of radiant floor heating at that.



Put another way, if your basement WERE warm enough to heat your first floor, you also were heating the ground surrounding your home and just whom does that benefit?  If the basement is now cooler, your delta-T to the outside is also. Your floor losses might increase a bit (maybe 3 BTUH per SF with a ten degree temperature difference). Over 1,000 SF, that is a small radiators worth.