Remove redundant steam mains?

Patrick_North

<span style="font-size:12pt">know, I know- “if it ain’t broke…”</span>

<span style="font-size:12pt"> </span>

<span style="font-size:12pt">I have one pipe steam and not one but two main “loops” around the basement (two go left, two go right). This was done originally to separate the first and second/third heating plants- the house was an upstairs/downstairs duplex and had two boilers. </span>

<span style="font-size:12pt">Now we have a single boiler (new) and occupy the entire house. I plan at <em>some point</em> to consolidate the mains into a single loop. This will save loads of room in the basement if/when it’s finished as a gameroom, and it will allow me to fixed an unorthodox header (search “funky Header” if you want the gory details.) that is likely affecting efficiency to some degree.</span>

<span style="font-size:12pt">This rationale aside, does anyone have opinions on whether this project should be done sooner than later? I imagine I’m losing some efficiency by heating up and distributing steam over at least twice as much 2 ½” main as is necessary. </span>

<span style="font-size:12pt">We’ve got a long list of home improvements to tackle- just trying to prioritize.</span>

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<span style="font-size:12pt">Thanks for any thoughts,</span>

<span style="font-size:12pt">Patrick</span>

Nick_C

My thoughts

You won't save much, if any, on efficiency.  The boiler will continue to burn the same amount of oil/gas per minute and, my guess, is that you won't be running the boiler for any less time after the retrofit, particularly if those mains are well insulated at the moment.  You will likely need to replace those loops with bigger pipe (assuming they were sized correctly to begin with).  So, if you have two mains of 2.5", you may need to replace them with a single 3.5" main.  That 3.5" mass won't be equal to the mass of 2 x 2.5" pipes, but it ain't gonna be far off.

Do this for aestetics and other reasons, not for expected energy savings.

Also, if you do this, start your calculations from scratch.  Use a properly sized main loop with real returns and parallel flow.  You'll be thankful you did.

Unknown

Mains

With the caveat that I'm not a steam pro, I've read somewhere that you are now better off with several short mains rather than one long main.  Long mains go back to the coal days with the constant heat output and today, with the on /off heat output of the modern boiler, shorter multiple mains are more desirable from an efficiency standpoint.

I'm a person that likes to leave all their options open and with that it mind you might want to consider preserving the extra piping if there was ever a chance you might want to convert the house back to apartments.

- Rod

Patrick_North

More info

A couple of mitigating factors:

1. As I read LAOSH, the 2 1/2" mains will still be ample, given the connected load of around 550 EDR, split over two mains. (Does make me wonder if there's benefit in upsizing to 3".)
2. I won't be trading four short mains for two long ones- I'll actually end up with two mains shorter than any of the four I have now.
3. This won't be a duplex again, at least not while I'm above ground

Still sound like a low priority item?

Thanks for the input,

Patrick

RAF

You might

You might want to price out the fittings and pipe before you tear anything out.