conversion from one pipe steam to hot water

billchat

I would like to convert a gas one pipe steam system serving a 2 family 2 story to a hot water heat system or at a minimum separate the system into providing both apartments with separate heating and t-stat. Would it be easier to keep 1st floor on steam and add a new gas hot water for 2nd floor or add 2 new systems. What about chimney sizing?  A second thought what about adding low ambient Slim heat pumps units on 2nd floor and leave existing steam as backup? thoughts 

mcsteamy

It would be easiest...

and cheapest and allow for A/C to just rip out the whole thing and install forced air if you want separate systems.  (Heresy, I know).  



I looked into converting single pipe steam to hot water once. It is ridiculously expensive and generally not recommended.  First, you need to make sure your radiators have a connection along the top.  Old single pipe steam rads don't.  If they do, you need to pressure test all the rads and ensure no leaks.  Then you will need to run PEX throughout the whole building to the radiators, rip out the steam boiler, and install two new hot water radiators. 



Whatever money you think you will save by doing this, you probably won't.  If the idea is to send the tenants the heat bills, you're going to give up the money on rent instead.  If its an issue with your advertised rate, just advertise a lower and then tack on a heating charge.  Put TRVs on the overheating radiators, spend money on insulation, and call it good.  You'll come out way ahead. 



I know people that did a conversion once.  They spent enough to cover the heat bills for 10 years, and saved about 10% a year when all was said and done.  Waste of their time.

JohnNY

Converting?

It's not so much a "conversion", but more a complete installation from scratch of a hydronic heating system since: A. you can maybe re-use your steam radiators, but you probably shouldn't, and B. you can maybe re-purpose your boiler but you probably shouldn't; and finally C. you'd benefit by putting in all new properly sized risers regardless.

What's left? Nothing.



Going from 1-pipe steam to hot water means a new system entirely.



Don't let that scare you away if that's what you want. Companies like mine and others do it all the time.

Steamhead

All you need to do

with the piping is run a new set of mains and returns in the basement to serve one of the floors. Since almost all of these systems have separate risers for first and second floor radiators, this would avoid making any changes in the units themselves.



Then install two properly-sized boilers, vent both sets of mains properly and you're done.



Steam is a better solution than hot-water in this situation, since if the tenant doesn't pay the utility bills and they get shut off, the pipes won't freeze and damage the building.

jumper

is this common?

>> Since almost all of these systems have separate risers for first and second floor radiators, this would avoid making any changes in the units themselves.

Steamhead

Pretty much every one I've seen

had the first-floor rads on separate runouts and risers from the steam mains. It was common, however, to put third-floor rads (when used) on the same risers as second-floor rads. 

nicholas bonham-carter

1-pipe problems

I assume from your post that your building has been having high fuel bills, and perhaps complaints about uneven heat from the tenants. Why not make the present system work as it did when first installed? The original owners would not have tolerated those conditions, and would have called the steam expert to restore the system to original operation.

Why not send some pictures of the boiler, and radiators here and we will help diagnose the source of the problem.--NBC