converting steam to hydronic

Brad White_9

Converting a steam system to hot water is sort of like converting to Judaism. It requires study and a wee bit of cutting :)


Ahem.


It is possible of course but like any endeavor, you have to do it right.

The manner of piping has to be appropriate to the application; I could not tell you that monoflo, series loop, reverse return, etc. are the right thing to do without seeing the job. Call those the details of means and methods; all can work.

Are you planning on keeping the boiler and converting it to hot water? If you are replacing it, not performing a "gender change", you might as well put in a mod-con boiler. Then the need for a bypass and shock protection goes away.

Cast iron is worth keeping, almost always. KNOW THINE EDR and thy heat loss, yeay verily... you may be surprised to find that there is abundant radiator surface that will allow use with hot water. If the house was insulated, then ever more so. But know and compare both before you decide. Keep the cast iron if you possibly can and put TRV's on them. Do not mix copper fin tube with cast iron on the same zone.

Fin-tube is good to wash the perimeter with a film of warm air but it is a convector, not a radiator... They generally require warmer water because of this fact, so are not specifically as efficient. Remember, you may have plenty of radiator surface right there already. Use it, please.

You may consider a homerun system using PEX-AL-PEX rather than copper or steel. Some pipe options are yours if you will only try them.

Heat output for steam as you know is 240 BTUH per EDR in a 70 degree room. With 170 degree average water (180 in, 160 out) this drops to 150 BTUH per EDR. The output drops 20 BTUH per EDR for every ten degrees drop in average water temperature. You may find that you have enough radiation to heat the house with 150 degree water, who knows? (You will.)

Hope this helps

Brad

Saggs

I'm sure this has been beaten to death but couldn't get the Search to work. Is it realistic to convert an existing 2 pipe steam system to hydronic if the old black iron pipe was removed and the lg radiators piped in series or mono-flow to zone them properly? How much less is the heat output of water vs steam? I know I would have to put in a bypass loop of some sort to prevent boiler shock. I'm thinking it may be cheaper and more effective for the HO to go w/ baseboard. All things being equal, is base board more efficient than Lg. cast iron radiators? I really appreciate any help-Thx

Steamhead (in transit)

And with all that labor

the ROI is still rather small.

If this is a 2-pipe system it's probably some sort of Vapor system. Vapor was the Cadillac of heating in its day and is still one of the most efficient systems out there. With a new boiler, proper air venting and completely functioning traps, it'll work great.

Have you located any manufacturer's info on the system components (valves, traps etc) that could help us ID the system and get more specific?

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Brad White_9

Absolutely.

I should have prefaced my comments that my assumption is that the system is otherwise on it's way out and you are at a crossroads. I would not advocate changing out a steam system for the sake of energy efficiency alone.

I would strongly advise that if it is working steam, work with it in all the good ways advocated here. If you must change to HW, do so with respect for the radiators, please.

Thanks for the tap, Frank.

Christian Egli_2

This is art

Brad, you're particularly inspired today. This wee bit of cutting brings in just the right amount of fear anyone should contemplate before the conversion.

Maybe the best signal to wait for is the apparition of the black mold, then whether it is the Virgin Mary or Elvis, we'll know what to do. That post of yours was great as well.

Great fun. Thanks for the knowledge.

To put it all together, in music no less, here is a (apparently one of very few and old) recording of the head soloist singer of the Sistine chapel. Well, perhaps you can guess what happened to Moreschi. Popes have since banned this procedure.

Click further on the Ave Maria, 1.6M, then listen, it's quite moving.

1904 Recording of Alessandro Moreschi singing

The same link to paste

http://www.archive.org/details/AlessandroMoreschi

Brad White_71

I had to LOL, Christian....

Leave it to you to find a 1904 original pilot recording of "The (Castrato) Sopranos" by Alessadro(Alessandra?)Moreschi. You are unbelievable! And your writing is something to which I certainly aspire.

The recording indeed was quite moving, as were my hands as they went to protective posture evident in every briss I've attended.

Thanks for the, ah, tip.

(:^)>

Brad

Saggs

Thanks for the inspiring replys.. The HO has a 30 yr old peerless boiler- not sure who manufactuered the traps, I'll check. His big yank is the lack of hot water coming from the coil and having to leave the boiler on all summer. Maybe a gas water heater and a newer more eff. boiler w/ steam would be the way to go. Any reccommendations?

Brad White_71

Lack of domestic water

You may want to see recent threads on indirect water heaters which seem to have a plurality in favor of them, or at least for general information.

I surmise that after 30 years that in-boiler coil is full of minerals. An indirect can be run off of the boiler below the waterline but it may reduce the apparent EDR (quench the steam) if it runs during steaming and the sizing is tight.

Nothing wrong with a separate DHW heater though, especially if you are firing with oil, higher mass and older equipment.

My $0.02

Brad

Steamhead (in transit)

For what it's worth

I have a 40-gallon Phase 3 indirect running off a W-M 268 that two teenagers haven't been able to run out yet. I think this is the way to go.

No need to convert the whole system to solve a DHW problem.

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Saggs

Can you give me advice on a good 5 section oil fired steam boiler w/ good efficiency? I think you're right about the phase 3 below water line. Can this or should this be a cold start boiler? Or is that inefficient w/ a steam system?

Steamhead (in transit)

Have you measured

the radiation for a total Square Feet EDR figure?

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