Throughout the fall and winter months homeowners are concerned about managing their heating costs among all of the other holiday worries.  We find that most of our customers concentrate on insulating their steam or hot water heating "supply lines".  The obvious energy loss is radiating out of the supply lines so insulating those pipes first should be the priority, however your steam boiler pipe insulation project doesn't end there.  You also need to insulate steam condensate return line pipes for hot water.  Why you ask?

Reasons to Insulate Steam Condensate Return Line Pipes:

1.  Increase Efficiency:  Insulating the condensate or hot water return lines reduces heat loss from the water returning to the boiler.  The hotter the water returning to the boiler is, the quicker it is to convert back to steam, which takes less energy to accomplish.

2.  Reduce "Hammering" Noise:  Heating systems may produce a "knocking" or "hammer" noise during operation (most common during heat up or cool down).  This loud banging noise can be a result of many factors, one of which is lack of proper fiberglass pipe insulation.  If you don't insulate steam condensate return line pipes, the piping will be cold and when the extremely hot condensate hits the cold piping you will hear those loud bangs.

3.  Freeze Protection:  Most homeowners recognize that a water line located in a crawlspace can potentially freeze.  What most fail to realize is that heat return pipes are full of water as well! If you go away for a long weekend and turn the heat down too low, those return lines can freeze!

4.  Protect the Actual Pipe: You may ask yourself how installing pipe insulation on the outside of a pipe can protect the inside of the pipe.  If heating return pipes are bare, the colder the condensate will get before returning to the boiler.  The colder the condensate water is at point of reboil the more carbon dioxide it absorbs.  This in turn causes the creation of carbonic acid which corrodes the pipe from within.

In conclusion, you need to insulate steam condensate return line pipes to increase your energy efficiency among other benefits.  The next question would be how much insulation is enough on a return line pipe?  Due to the lower temperature of the return when compared to the supply, you can usually reduce the thickness of the pipe insulation.  If you are using 1", 1-1/2", or 2" thick pipe insulation on the supply lines you can reduce the thickness to 1" on the return.