New Heating System Planned??

Paul MacDougall

You could investigate a mod/con boiler and retrofitting the steam radiators for a two pipe hot water system. It is possibble to fish 1/2 pex lines (feed and return) to each radiator from a manifold station. Add some TRV and a wilo pump and you would have a great little system. Just a thought. I'm in the Boston area if you want to shoot me an e-mail with any more questions.

Jack_33

Upgrade to Very Old System

We presently live in a 1947 small (1300 sq. ft) cape located outside of Boston.
The present one pipe and original steam boiler system (no heat upstairs) is original to the house. Over the past few years I have been improving upon the entire envelope and that continues.
We are now at the stage of looking into the heating system. Where to start? What to look into? I would prefer to replace the existing system with a much more efficient hot water based system. Why not?
I am wrong in thinking that the present heating system from 1947 from the huge boiler to the pipes designed for that system cannot or should not be replaced?
Thanks.

Bob Gagnon plumbing and heating

Replace the Boiler

But keep the steam. Steam heat is very comfortable and efficient when installed properly.

Thanks, Bob Gagnon

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Rick_91

Bob with all due respect

Efficient compared to what? A campfire? A hypocaust? Certainly not as efficient as any Mod/Con gas or Buderus G125BE oil. These are really very, very, very comfortable and efficient when installed properly.

Please explain how using energy to heat water to 212'F to where it changes to steam is as efficient as running temperatures at 120'F

Thanks!

Kool Rod

David- I'm a homeowner with an old steam system and was faced with the same questions. A lot of people were telling me that steam was "old fashioned" and that I needed to "modernize" and "go green".

I ended up staying with steam as I thought that the payback with installing a new system just wasn't there. Steam is very simple and reasonably maintained, very long lasting. My boiler was 70+ years when I replaced it. I also think that from a economy standpoint steam, in reality, now rates very high. The boiler may not be quite as efficient,(though the new 3 pass steam boilers, like Burnham Mega Steam, are surprisingly efficient) as modcons, though on the other hand it uses a lot less electricity as there are no pumps etc., needs a lot less maintenance and has a extremely good track record for longevity.

My steam system went 80+ years with minor maintenance and yours (from 1947) has gone 62 years. Are "Pex" and Modcons going to last as long? There are serious questions whether some modcons will make it through 10 years. Use the Search feature on this site and use in the Query box, the word "Modcon" and in the author box the name "Perry" and you will find a very interesting discussion on modcons; questioning how long they will last.

There is also an electronics issue as all these "modern" systems run by computer "black boxes". Are there going to be replacement electronic components available in ten years or am I going to then have then buy a new boiler just because I can't get replacement computer parts?

I think if I were you I'd seriously consider staying with steam as it has proven longevity and as you're just replacing the boiler, the monetary outlay is the minimum.

I think the modcon boiler is a very good concept. However, I don't think it's development has reached the levels of maintenance, reliability and longevity yet to the point where I would consider having one. I have no interest in being a "pioneer" and paying the cost of failed "experiments"! A good example of these "experiments" are some of the class action "pex" lawsuits which are going on now.

I guess what I'm saying is just be careful and don't get taken in by the hype and buzz words flying around like: "Green", "Modern", "Efficient". Any system you are considering needs to be carefully considered and researched
with regards to total economy - Installation costs, fuel, electricity, maintenance, longevity and payback.

- Rod

Edit: I should have mentioned that you can run a hot water leg off your steam boiler which might be an option for you in adding heat to the new "areas" of your house if running steam pipes is inconvenient.

Rick_91

This question hasn't been answered

Please explain how using energy to heat water to 212'F to where it changes to steam is as efficient as running temperatures at 120'F?

Hi Perry! I mean Kool Rod

Bob Bona_4

typical.

Guy comes here bluntly stating that he prefers to switch to hot water. He has no heat at this time on the second floor. He has bang-bang one zone. He has to watch water levels, blowdowns,and prepare to replace wet return lines at some point. Typical 40's steam system in a cape. This is 2009 now.

The cresendo starts. "Keep the steam!" Like the conversion will come out of whomever wants the OP to keep the steam's pocket. He. Wants. To. Convert. It's his money, let him spend it on what he wants.

And, what he wants is a modern hot water boiler driving a manifold system, 1/2" pex piped to new heat emitters- panel, cast iron, even fin tube bb. Zones upstairs, first floor, and possibly the office/rumpus room in the basement, now that the clunky low hanging steam piping will be gone. Hot water production is now a breeze. Room by room TRV's would be icing on the cake.

It's his money.

Bob Bona_4

fear mongering

does not help.

Perry, to his credit, had quite a dissertation on metallurgy as it applied to boiler blocks. I read every word of it, I admit.

But,to speculate on boiler longevity and arbitrarily suggest a boiler lifespan is not productive nor useful IMO. I'm trusting the mfr's I have been dealing with for the last 20 years to give me a product that I can depend on lasting at least 12-15 years. If not, then something is seriously wrong with this world, and my faith in this trade would be very shaken. This is disregarding abnormal site conditions such as suspect water quality, lack of maintainence, air pollutants, poor piping practices at the boiler, etc..

I have taken years to find a PEX product I can trust, whether it be flying across the country to it's point of origin, talking and listening to guys all over the world about what's working, and what isn't. I use these products day in and day out, and have many, many jobs behind me that has proven that the direction I'm taking is the right one. I would not call this "experimentation".

Rod, with all respect, you are dissing the very products I use on a daily basis-believe in-because they work. Further, I would not want to taint a prospective client with internet speculation.

Rick_91

I agree with Bob

You said and I quote

"I think the modcon boiler is a very good concept. However, I don't think it's development has reached the levels of maintenance, reliability and longevity yet to the point where I would consider having one. I have no interest in being a "pioneer" and paying the cost of failed "experiments"!

I think most of Europe, HTP, Buderus, Viessmann, Triangle Tube, Burnham and everybody else thinks that statement doesn't hold water (maybe steam)

I too am interested in how it can be efficient heating water to steam instead of the traditional low temps of a condensing boiler. Can a steam-head explain that?

Charlie from wmass

If a mod con is used on a non low temp designed system the reality of 90 percent plus efficiency is not there. Steam also does not use anywhere near the electrical consumption of steam. The parts are simple and the piping if done well can be zoned by the room with out the tear out of a radiant system. I see way too many alleged radiant systems that cost a fortune to maintain. If done well either one can heat well and quietly. One just needs to realise what is involved and what the options are. I am waiting for the system 200 guys to chime in now how their boiler is better than any mod con. 300 guys 1300 ways to do the job. One will be right for this home owner. And as a end note I still like perimeter base board the best.

Kool Rod

I'm not really quite sure how to answer you as I don't wish to turn this into a debate. The bottom line in what I was trying to say is that if one is buying any heating system you need to carefully investigate all the parameters: costs of hardware and installation, costs of fuel, electricity, maintenance and payback longevity.

On Modcons - I would pay particular attention to what Perry said in his "dissertation". I have some experience with metal corrosion in a marine environment, enough to know that Perry is quite qualified on the subject of metal corrosion so I would take anything he said on that subject seriously.

Bob, I'm not dissing the products you use everyday mainly because I don't know what exactly you use and even if I did,
I probably wouldn't be qualified to judge them. What I do know is there are a lot of inferior products out there, especially some of the stuff now coming in from overseas and I know people ("pioneers") who were "burned" by them. As you said yourself, it took you years to find a pex product you trusted. And that is what it all boils down to: The tremendous importance of getting a competent experienced pro, like yourself and the others on this board, to guide you through the "caveat emptor" heating world. Someone who knows and uses the "right" Pex.

- Rod

John Mills_4

Good points here

While we dry heads don't deal with mod-cons, we deal with high end forced air products. Too many times we've pulled out a 60% furnace that the customer had 25 years and all they did is change a thermocouple or 2 only to put in a boiler only to find that a very expensive board or variable speed motor goes out in a few years. Fortunately everything forced air comes with at least 5, some 10 year parts warranty but customer still pays labor. Or out of the 5 year parts warranty if a customer has to pay $1200 for a variable speed blower motor change, you will have 1 mad customer on your hands. That's why our extended warranty sell rate is pushing 90%

So if someone takes out a steamer at 80% and spends a fortune going forced hot water with a mod-con only to have one of the expensive components go our in a few years, what is that doing to the payback? All these components stuffed in that little boiler are pricey and since many are made in some 3rd world country to keep the price down, may not be all that reliable.

Family home folks lived in for 35 years. The old boiler in 33 years needed 1 pump motor and 1 gas vavle. In 13 months of the new one, had a no heat. Hot surface ignitor out. Fortunately I was home and could change for the minor cost of the part.

Steamhead (in transit)

The myth

that hot-water systems are always more efficient than steam systems refuses to die. As I read David's original post, what stands out is that he's looking for better efficiency.

The fact is, as far as we know, there has never been a scientific, apples-to-apples comparison of the relative efficiencies of transporting BTUs by steam as opposed to hot-water. So the guys who continue to post that hot-water is the more-efficient system are simply expressing their opinions. We have asked many times to see the data that backs up their opinion; so far we haven't seen it.

And please don't bring up that article about the school system that replaced some steam systems which were on the verge of total collapse with new, state-of-the-art hot-water. That was as flawed a comparison as all the rest I've seen. I'd like to see how those new systems work after being neglected the way the old steam systems were. I doubt it'll be pretty.

I think that most of us would agree that a boiler should last more than 5 years. As we've seen, some mod-cons don't. And don't forget, 90%+ efficiency IS possible on a steam boiler. It's been done, but of course not in America.

David, it all comes down to how much money you want to spend and how much disruption to the house you can tolerate. A complete tear-out and replacement is a very expensive, messy process, and is not to be taken lightly. But it should be possible to add steam radiators to your second floor without too much trouble. The existing steam pipes and radiators are probably in very good condition, and would last for many more years. With a new boiler, and new wet return lines if needed, that system would last a long time. If you have a source of used radiators, you could even downsize the amount of radiation in each room and install a smaller boiler when you replace.

And you'd have a good, reliable system that would would be much, much less likely to freeze up in an extended power or fuel failure, the way hot-water can.

BTW, check out www.steamradiators.com for some very nice, modern steam radiators.

"Steamhead"

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Steamhead (in transit)

It's easy

as I see it: First, in a steam system there is much less water to be heated. Second, the delta-T at the radiation is higher than when low-temperature water is used, which balances out the higher delta-T at the boiler. Assuming the system is well insulated- which ALL systems should be regardless of type- the relative efficiencies should be pretty close.

Unfortunately, until we have a proper comparison, this is little more than an opinion.

"Steamhead"

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mark ransley

New pipes and radiators for HW, alot of money payback is maybe to long. New steam boiler, less money. Do you have AC and ducts.

Buzz G.

Steam vs HW

is not as big a question for this person as whether he can be more efficient. He may or may not need a new boiler. He definitely wants heat upstairs. Adding some radiation there should be feasible. How come no one has had him calculate his home's heat loss and see what his needs are? It would seem that would still be first since he says that he has improved the envelope. Once he knows his needs then he can pick the irradiation for the upstairs and calculate how big is his BTU requirement. Then he can decide how to meet that requirement.

ttekushan_3

Haven't really had time to dedicate

to this thread. In a systems approach the boiler is but one component. The drastic difference in how each heating medium works disaffirms the concept of boiler temperature being the only difference between systems. Boiler temperature alone detrimentally oversimplifies the model almost to the point of uselessness. Emitters are hotter as well and and even though supply piping is also hotter, the return piping carries virtually no heat energy at all.

Fact is, there's nothing green about central heating. One hundred percent of the flame's heat goes outside. We just like to see as much of it as is practical hang around indoors for as long as possible. To suggest that the linch pin of the entire system comes down to several percent efficiency in fuel-to-heat delivered in the boiler without knowing anything else about a heating system's design and control, envelope ventilation and insulation (including radiant barriers) seems a little absurd to me.

In other threads I've gone to great length in going over the giant difference in the dynamic nature of steam and other media. This includes some discussion of how thoroughly a steam heat exchanger actively couples to a room's conditions. Proof of this is near perfect extraction of all enthalpy at a radiator. Delta T may tell you something at the boiler, but nothing of the one-way heat transaction that's occurred in the space to be heated, let alone any dynamic self balancing of heat output without the aid of feedback controls. There are plenty of examples of systems that have utilized these characteristics to full advantage and reaped the benefits in operating economy. Other compelling designs exist that do away with large pipe sizes and most traps, etc., virtually doing away with the pick up factor in a steam boiler's sizing. Add full modulation, and, as they say, "now we're cooking with gas!"

Getting tired now. I've been working hard fine tuning old school and church steam heating systems so their fuel use is reduced to the levels projected by other contractors in their proposals for complete conversion to hot water heating. The clients love the results. I'm sure the prevailing industry would hate them. Anecdotally, other contractors who have returned to see if the clients are ready to make the big change yet are swiftly sent out the door with a "no way, not anymore" response. heh heh. :-)

Terry

Jack_33

Upgrade to Very Old System

Thank you all for your responses, much appreciated.

Am I wrong in understanding that the pipes used in our presently old system were designed with our huge boiler in mind?

Can only a replacement of a new boiler be done and not replace the old pipes as well?



Thanks again.

ttekushan_3

pipes

If you change out the system, start fresh. Don't apply the high pressure of water heating to those pipes. Steam operates at very low pressures and have never stressed them.

My suggestion is, whatever you do, have a competent firm do the heat loss calcs, system design and installation. No matter what medium you use, the implementation will make or break it.

If you expand on the steam, I'd keep the piping and change out the old radiators to smaller ones to reflect the improved insulation you've installed. If the new radiators are half the size, then you could add radiators to the existing piping and still be within the capacity of the existing mains. The usual difficulty is finding someone who can implement this competently. There's that word "competent" again.

Terry

Bob Gagnon plumbing and heating

Mod Con Dude

I have many customers with steam and they have very low fuel bills. One way you can save with steam is on set back. You turn the heat down to 50 down stairs at night and it will come up quickly in the morning, same thing when you are at work. With radiant you are going to keep the heat on all day and night, both floors. I would run a baseboard loop up to the second floor and maybe another one for the living room and bath for temperate weather. You would rip up all the floors and install radiant ?? What would that cost. Older houses are not insulated that well and leak a lot of air, would you rip out all the walls and reinsulate?Would you replace all the leaky windows too? Are you sure radiant would keep up? That along with the increased maintenance and replacement cost for the mid con might never pay back. Starting off new I would install radiant but steam just seems to fit an older house, it is very comfortable and radiators also give you radiant heat. If you have to replace your mod cons every 12 years or so that alone may never pay back fuel savings, whan a good American Made cast iron boiler will probably last 30 or 40 years- or more.

Signed, The Best Heating System for the House Dude.

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Kool Rod

David - The pipes were originally designed to get the required amount of steam to each radiator. They are not designed to size of the boiler.

In mine and in most cases the only new piping done is in the immediate vicinity of the new boiler as the new boiler inlets / outlets naturally aren't in quite the same position as the ones on the old boiler. The biggest efficiency benefit you have already done and that is in insulating your house.

- Rod

bb_11

Find A Pro

David:

Click on the find a pro link and enter your zip code. Have someone come out and look at your house. The total picture needs to be looked at before you make a change.

Have an estimate for an upgraded steam boiler, and a new hydronic boiler and see what the differences in price. As stated above, there may be more work required to change over to a hydronic system, which of course means more $$$$ out of your pocket.

bb