Steam to Hot water boiler trim?


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Old 05-12-08, 06:42 AM
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Steam to Hot water boiler trim?

My steam boiler is a 3 years old dunkirk PVSB -5D. and thinking about making it a water boiler. its currently a 1 pipe system to each radiator and wonder if if i can use the exsisting piping(+ add a return) or should i use new smaller diameter pipe. i'm doing reasearch to find out if i should take on this summer project. thanks
 
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Old 05-12-08, 07:55 AM
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Some believe converting steam to water is a daring conversion due to leaks. Follow the list below.
1.Run your system up to 10 psi and search for steam leaks.
2.Are the radiators nippled at the top?
3.Can you remove the plugs on the end of the radiator for returns?
4.Check with the boiler manufacturer if they have a steam to water conversion kit for the boiler.
5.Is it possible to do a reversed return system in your home?

Why not improve your steam system?
1.Vent the mains faster
2.Verify the radiator vents are working properly.
3.Check you pressure control is not above 2 psi or 1.5psi dependent on the control
4.Are all mains and near boiler piping insulated?
5.Was the boiler combustion tested?
6.Verify the near boiler piping is correct to verify dry steam
7.Verify the water is not surging or foaming

Was the boiler sized properly? If not it is still going to be inefficient when it is converted to a water boiler. If converting make sure you use a boiler bypass and not a system bypass.
 
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Old 05-12-08, 07:01 PM
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I don't like residential steam heat but changing an existing system to hot water is a HUGE project.

What do you hope to accomplish?
 
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Old 05-16-08, 10:15 AM
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well- hot water is better heat i think. flowing to/thru all the radiators. more efficent also. radiators stay warmer longer.. wondering if i can use the old 2 "steam piping and just add return line? i dont know if i want to take on this project yet or leave well enough alone..
 
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Old 05-17-08, 04:06 PM
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I'll certainly agree that hot water heating systems are better than steam for several reasons. Yes, if properly designed they can also be more efficient.

However, the heat output of your radiators will be far less with 180 degree (or less) water than they will be with 215 degree steam. Much of the heat released from a steam radiator is due to the condensing of the steam to water which releases 970.3 BTUs per pound of steam condensed back to water. You won't get that with a hot water system so unless you have plans to augment your existing radiators with more heat emitters you will be far short of the requirements of the house.

Using the existing 2-inch steam piping along with the existing radiators will mean that your system will have a huge amount of water in comparison to a modern boiler. This will require a "boiler protection" circuit on the boiler and will cause your system to be slow in reacting to temperature changes.

If it were my system I would probably scrap everything and start from the beginning with radiant floors, panels or baseboard convectors.
 
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Old 05-18-08, 10:18 AM
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I'm gonna leave the steam system intact. maybe adjust the steam valves for more even heating. but i'd like to add an indirect hot water tank to my steam boiler tho. i heard it can be done.
 
 

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