Replace steam with Steam or Hydronic Boiler?

Christian Egli

To save on heating fuel, about the only things you can do are: add more insulation, decrease the size of the home, lower the thermostat, move to Florida, and lastly, buy a sweater.

Sounds helpful, no?

Changing the method of heating yields only dubious changes in efficiencies. A forced air guy will tell you a furnace is the way to go; I will tell you steam is the way to go, you're lucky you've already got something top-notch. At best, the differences could be marginal in view of what insulation will do.

In other words, a conversion will never yield the savings you dream of. What will get you a good way along though, is a complete system survey and trap maintenance.

If you have steam, your system has probably been ignored for a long time just because it never stopped working. Meanwhile some traps have probably become defective. The traps are the only moving things that need maintenance and they make the difference between good and bad heat flow throughout your home.

The best part, trap maintenance and boiler tune up is much cheaper than a conversion, and you avoid the many possible disasters with a rip-through-your-home renovation project.

If you're also thinking about adding AC, think ductless split units.

Best of luck

Tom_31

Steam or hydronics

In a residence, what is the best route to take to save fuel keeping in mind the payback period when faced with the choice of replacing a steam boiler with new steam, or a new hydronic system?

Joe Grosso

Keep the steam

With a new and properly-installed boiler, insulated pipes and any steam-distribution problems fixed (which is rather easy to do) a steam system will give the same comfort and approach the efficiency of hot-water. And if there is an extended power or fuel failure causing the building to cool down, a steam system won't freeze up like hot-water will. Most of a steam system drains completely dry when the system is off and cold- the exceptions are the wet returns in the basement and the boiler itself.

And by keeping the steam, you won't set yourself up for a host of pitfalls a conversion might have- go here for more:

http://www.heatinghelp.com/newsletter.cfm?Id=22

If you can take some pics of your system- boiler, some radiators, basement piping etc- we can give you some more specifics. What type of boiler do you have now? And where are you located? Betcha there's a real good steam man near you- if you're in the Baltimore area, e-mail me.

Robert O'Connor_12

Steam or...

Stick with steam. Forced water is more efficient, however the time it would take to re-coup your installation cost would make it cost prohibitive. Get a quality higher efficiency steamer, fix your system troubles and enjoy!

Robert O'Connor/NJ

Constantin

I'd have a contractor check it both ways...

...like others have said, steam systems can be efficient when maintained properly, just like most heating systems. Are there inherent physical reasons for forced-water systems to be potentially more economical to run than a steamer? Sure. Are those differences large enough to warrant ripping out steam systems for the sake of efficiency? Not yet, to my knowledge.

So, I'd have your contractor look into the matter by pricing it out. If you're about to undertake a gut job and all the walls will be open, etc. then the marginal cost difference comes down somewhat. If the current steam pipes are in the open and the missus wants them inside walls for decorative purposes, the margin comes down again, etc.

It also matters what is happening insulation-wise inside the home and the emitters you'd use for a forced-water system. Sometimes, steam radiators can be converted to forced water but only a detailed survey will tell you. If the home has been insulated since the steam system was put in, the present radiators might do just fine on a forced-water system to keep the place warm.

The savings also depend a good bit on the boiler itself. Gas boilers now come in low-mass, condensing, modulating varieties whose marginal cost over "standard" boilers is repaid in a matter of years. On the oil side, there is only one condensing boiler (at a fixed 75kBTU/hr capacity), and no modulating burners for the residential market. Thus, if oil is your choice of heating fuel, then switching between steam and forced water won't make that much of a difference.

Anyway, it all starts with a heat loss calculation and understanding what you have vs. what you want to have. For example, it is quite likely that you'll benefit a great deal more from installing high-quality storms and wall-cavity insulation than from switching heating systems.

Tom_31

Condensing Oil boiler

What is this condensing oil boiler!

Constantin

Monitor FCX

The Monitor FCX is manufactured in Europe with a Heatwise burner from Long Island. By all accounts it is a great unit which will happily fire regular #2 heating oil all day. Tom at BNL loves his unit and everyone I have met at MPI struck me as stellar as well.

While it is unlikely that the FCX will ever be able to benefit from a modulating burner due to its design, you cannot argue with the efficiency that the unit brings to bear. With take-offs for an indirect tank as well as a heating system, plumbing this boiler in ought to be simple. However, to really reap the benefits of condensing oil boilers, you have to have return water temperatures well south of 110°F, IIRC.

If my heat loss had been in its territory, I would have seriously considered getting one. However, at decision time I would have had to buy two...

Joe Grosso

Some more steam links

These are some older posts from the Wall, and describe the savings possible by keeping the steam:

From Dean- he saved a bunch and pays less for fuel than his neighbors with scorched-air and hot-water:

http://forums.invision.net/Thread.cfm?CFApp=2&&Message_ID=171303&_#Message171303

A not-so-rough comparison of steam vs. scorched-air in similar houses:

http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=25079&mc=7

One of my jobs:

http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=22035&mc=22

The results of insulating an attic:

http://forums.invision.net/Thread.cfm?CFApp=2&&Message_ID=149824&_#Message149824

Hope these help!