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Should we convert from steam to hot water

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Andrew Hagen_2
Andrew Hagen_2 Member Posts: 236
Repairing a malfunctioning system is almost always the best bang for the buck, whether it's steam or hot water.

A perfectly functioning steam system will never be as efficient as a perfectly functioning mod/con low temp hot water system. Estimating the difference can only be done on a case-by-case basis due to the infinite number of variables involved.

Retrofitting steam to hot water has many potential pitfalls as mentioned above. With a one-pipe system, retrofit to hot water probably means replacement of the entire system. Your radiators may or may not be of a design compatible with hot water, and after 100 years of breathing steam may or may not hold water. This type of conversion does not simply involve replacing the steam boiler with a mod/con and then it's 95.1% efficient.

To save fuel, attack in this order:

1. Make sure the system is functioning properly, or at least the best it can.
2. Reduce the heat loss.
3. Make system upgrades. If the boiler is decades old, plan for replacement.

It is not inexpensive to make an older home energy efficient, and fuel bills can eat you alive. I would rather invest that money, that would have gone to fuel, in upgrades to the property as opposed to upgrades to the utility's pocketbook.

In any case, finding a heating contractor that will perform an objective analysis of the system is one of your first steps.

Comments

  • john_170
    john_170 Member Posts: 4
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    Seeking Advice - Should we convert from steam to hot water???

    My wife and I just purchased an older home (1900's)with a one pipe steam system. Only one wall has insulation and it was recommended that we have insulation blown in and switch to hot water. Once there is more isullation the radiators may even be too large. We are being told that it will be more efficient, we could have zones, have greater options with our current radiators (reduce the size, do baseboard) and gain space in our basement. The ballpark estimate is 15-30K for the conversion. I would really appreciate any thoughts or experiences on whether the end result is worth the cost. We do plan on staying in house for many years to come. Thanks.
  • Brad White_9
    Brad White_9 Member Posts: 2,440
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    Put your money

    into improving the envelope and keep the steam. Unless everything is falling apart (I doubt it), there is a certain joy in steam. This from a hydronic (hot water heating) junkie.

    To convert for a perceived efficiency gain is hardly ever worth it. Too many systems have been tossed for great expense and no real gains. Much can be done to achieve individual zone control (TRV vent valves for example).

    If your radiators are too large, that is not the worst thing. Sure, it is darn nice to have them match their room's best new smaller heat loss but they hold heat so nicely and heat so rapidly...

    I say, make your steam system it's personal best! Assure yourself that the near-boiler piping is correct, your mains and radiators are properly vented, your piping insulated, your pressure controls set as low as possible, your pets spayed or neutered... all good things!
  • chuck_6
    chuck_6 Member Posts: 107
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    I agree with Brad

    John:

    Brad knows what he is talking about. Stick with the one-pipe steam and have insulation blown into the rest of the walls. Properly venting the mains and radiators will most likely make your system work better. I prefer Gorton vents. Measure the length of your mains and the diameter of the pipe. If you do, Steamhead will probably respond and tell you what you need. You can also speak to Ken Kunz at Gorton. His number is (908) 276-1323. Vents are a lot less expensive than an entire system and you can put them on yourself. Steamhead, Ken and others can tell you which vent to put on radiators.

    Chuck
  • Larry C_9
    Larry C_9 Member Posts: 7
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    Tighten the building envelope.

    Home owner here.

    In my opinion, the money priority is this:
    First, tune up the existing functional steam system.
    Second, tighten the building envelope.
    Third, get a heatloss calculation done for the building.

    THEN, decide if a new CORRECTLY SIZED heating plant is required.

    Use the "Find a Professional" link in the upper Left of the page to locate a steam heating contractor in your area. If nobody listed, come back here and give tell us where you are located, and somebody should give you some names.

    Good Luck and good heating.
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
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    From Another \"Hot Water Junkie\"

    Keep the steam and improve the insulation/weatherization of the shell as much as practical.

    Find a good steam man to get your system in top-notch shape and you can expect it to stay that way for decades with minimal maintenance and surprisingly high efficiency.

    To aid you both in your quest for a "good steam man" and to better understand your system, I highly recommend that you buy the book "So We've Got Steam Heat" available here by the owner of the website. For much more depth, order "The Lost Art of Steam Heating" as well. Spend some time reading and examining your system and you'll be able to determine if potential contractors really "know" steam as well as understand the routine, simple maintenance that will keep a one-pipe steam system in top-notch shape.
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
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    Keep the steam

    for all the reasons given elsewhere in this thread.
    Aside from insulating the building itself, the steam mains should also be well insulated and have proper air vents on their ends. Measure the length and diameter of each main and tell us what vent is on it. We can tell you what you need.

    Also, where are you located? Chances are we know a steam man in your area....

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  • john_170
    john_170 Member Posts: 4
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    The input is very much appreciated and I will take some measurements. We are on long Island, any recommendations for an A/C specialist as well.
  • ScottMP
    ScottMP Member Posts: 5,884
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    John

    I'm going to buck the the trend here.

    First I TOTALLY agree with putting the first money into the structure and the envelope. No doubt about it, loosing energy out the window and walls dosn't help no matter What system you have.

    Now, steam heat is neat and can be quite and those nice hot radiators are comforting. BUT ... you can't have radiant heat in your bathroom or kitchen. You can't have an indirect hot water heater. Hot water boilers can have much higher efficientys than steam. Zoning which will allow you more comfort and control of your home is difficult at best with steam. You can also get rid of those old pealing bulky cast iron radiators that are a piece of furniture in your room.

    Hot water heat offers much more flexbilty.

    If your doing it for the payback ... it won't happen in at least ten years or so (maybe sooner if the system is really in bad shape). If your doing for any of the reasons I mentioned above and you feel that saving fuel is important to you, then keep an open mind.

    I know, I just went against the Steam Maffia but there it is !

    Scott

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  • Brad White_9
    Brad White_9 Member Posts: 2,440
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    Message from the Steam Mafia

    Yo, Milne...

    Radiant is always possible especially in those small areas, using a heat exchanger or indirect as a buffer and the distribution. Not a problem, done all the time. I just cannot see a rip-out as a means of saving money absent some extraordinary circumstances.

    I still love you.

    Now, John- Long Island? Matt Mad Dog!!! (three exclamation points, please) Sweeney of Triple Crown P&H in Floral Park is tops, not to the exclusion of others. Matt wanted to know steam so installed his own house system from scratch.
  • Noel
    Noel Member Posts: 177
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    You CAN have radiant and Indirect DHW with steam

    Here's how you might do this, if so inclined. This IS allowed by boiler manufacturers and indirect manufacturers, but check with the specific companies for piping diagrams.

    Slant/Fin and SuperStor both use this diagram.

    Noel
  • ScottMP
    ScottMP Member Posts: 5,884
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    You Talkin to ME

    Brad, ever see a heat exchanger after a couple of years of rust and condensate ??? HUH ???

    I just don't think its scarilegious to do.

    I gave a customer a new boiler, panel radiators, radaint, an indirect HWH, constant circ with TRV's and a Comfortable House with more control over their inviroment.

    Scott



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  • ScottMP
    ScottMP Member Posts: 5,884
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    Boy the Hornets are stirred up now,

    and Noels Siding with Brad :)

    I've done it also Noel, I just don't think its the best way to go.

    Scott

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  • chuck_6
    chuck_6 Member Posts: 107
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    Call Matt Sweeney - Long Island Heating pro

    John:

    Call Matt Sweeney (Mad Dog) at Triple Crown. He is a steam specialist. A lot of your problems are probably caused by poor venting. You want to vent your mains and radiators properly. Also, insulate your pipes. Matt can help you, and speak to Gorton in New Jersey as well. You may need to experiment somewhat with the venting, but you are much better off fixing your steam system than ripping it out and putting in something else.

    Chuck
  • Dave Yates (GrandPAH)_1
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    70%

    Fugettaboutit, been there too Scotto. When it's right, it's right & savings can hit the 70% mark. Done several wid a modcon & da customers is nuttin short of happy.

    Den again, when youse is called in to doctor an old steamer what been abused by the last guys what yused da doorway method for sizing & youse gets da opportunidy tu du whuts needed, dey gets a quality install steam boiler hooked up tu der one pipe system whats now quiet as a choich mouse & deys happy tu.

    Dats why de needed a pro - to make da call.
  • Mark Hunt
    Mark Hunt Member Posts: 4,909
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    I am with Scott on this


    We all sing the praises of Mod/cons and how efficient they are. That is true, they are efficient.

    The OP was 100% correct. Once he insulates that building and "buttons up the envelope", his existing system will be more over-sized than it surely is already. Short-cycling anyone? How much more money would it cost for him to buy new radiators that match the NEW heat loss, replace the old rads and down-size the boiler??

    Even then, the new system will still be over-sized for the majority of the heating season. How does that lower dependency on foreign fuels and/or lessen a persons carbon footprint?

    Mark H

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  • Dave Yates (GrandPAH)_1
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    loves it he does

    Modcons love oversized cast iron radiators. While everything looks exactly the same upstairs (although with new valves), downstairs there's a heating plant that gently sips at energy while gently warming the water coursing through the old gal's veins.

    Proper homework tells the tale of future savings potential and if a conversion is possible.

  • john_170
    john_170 Member Posts: 4
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    Will do. We do plan an expansion so i'm not sure if that would be an issue for keeping the steam -- I could live with recessed radiators and forgo the radiant in the new room, the new room would be wood floor and not tile. If we insulate and tune the exisitng one-pipe steam system, is it really such an issue that the radiators would be oversized? Would we have to replace them?
  • Brad White_9
    Brad White_9 Member Posts: 2,440
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    In a perfect world... Maybe

    The ideal is to down-size your radiators to your newly improved lower heat loss. No one ever seems too but they talk about it a lot!

    Understand that the boiler is sized to your connected radiation so if over-sized for an uninsulated house, you will be that much more over-sized as must be your boiler. That is the down-side of all this.

    It all depends.

    The advice to get you to replace with a Mod-Con HW boiler is worth looking at. Crunch the numbers including total cost to re-pipe, the works. If you can keep the radiators (clean them inside and out) you have an asset that mirrors the original architecture and can add value in lower water temperatures.

    Key is, it all depends. Just do not throw out the steam for the sake of HW being the only answer.
  • J.C.A._3
    J.C.A._3 Member Posts: 2,981
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    Torn Between 2 love(s)...

    All great points raised here this afternoon/evening !

    I'm just going to throw a bit of "knowledge" into the ring.

    Without going into some great detail....MY sucess rate in converting radiators from Steam to Hot Water....is about 70%...and I've been at it for a while.So, the added cost of "replacement radiation" (to put it mildly...would be a WAG figure!),also has to be incorporated into the fold.

    SO...without further ado....Will the savings of the conversion MAKE the end cost worthwile in... THE TIME YOU PLAN ON SPENDING IN THE HOME?(caps mine)

    Big decision?...You bet!

    This is the thing that I would be asking straight up front.

    Now...if it were me, and I planned to stay there until they planted me/burned me up....I would DEFINATELY consider the change. Reasons... Fuel ain't getting any CHEAPER!!! Unless the "cold fusion folks" spring a TRUE surprise on us tomorrow...I'm thinking that the only way a fuel bill is going...is up!

    Would I be vested into making 215° water for the long term?,if I planned on staying there for a LONG time?
    Methinks NOT!(Remember...I just quit smoking 2 weeks ago...and if I get hit by a truck tomorrow...I'm gonna be pissed!...but they promise me.... I'm going to live longer now! Sorry..I had to throw that in there!)

    Will there EVER be a resurgance in Vaccuum steam systems? Again...Methinks NOT!I wish ...cause it worked, but noone remembers how! Sorry to the "Steam Gods" ! With the temps limited to 140°(in Europe right now..)...as a MAXIMUM...the RADIATORS will probably work well...but making steam at that temp requires too much of either, height...or too low a pressure...and building at 45,000ft just ain't going to cut it!(yet!)

    My boss...I think I'll keep him!

    Chris
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
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    Missing the point here

    There has NEVER been an apples-to-apples comparison- at least not that I can find, and I've been looking for a long time- of the relative efficiencies of transporting BTUs by steam as opposed to hot water in a heating system. The European practice of limiting radiator design temperature to 140 degrees to match their mod/con boilers does not mean that steam could not be as efficient at moving BTUs as hot-water. Remember, a pound of steam can move 970 BTUs- a pound of hot-water can only move 20-40 BTUs or so depending on the system's delta-T.

    Comparing an old steam system that has been neglected since October 1929 with a new hot-water system is not a valid basis for comparison. This is one of the things we could never get out of John Ruhnke when he went on his kill-all-steam-systems kick: what condition were the steam systems in before his friend/acquaintance/whatever converted them? Also, what problems did they encounter?

    Numbers, people.... we need meaningful numbers, and they aren't there. WAGs (thanks, Chris!) don't cut it. Neither do wildly trumpeted claims of lower fuel consumption unless we know what they started with. There is no room for used-car salesmen here.

    The experience I've had shows that if a steam system is using more fuel than a hot-water system would, there is something about that steam system that needs repair. And at All Steamed Up, Inc., we have numbers to back up our claims of reduced fuel consumption from repairing steam systems.

    In fact, we just got some more numbers: On the Calvert Court job featured in our Find a Professional ad, the rate of gas consumption at the end of the season (and some more tweaks we made over the winter) was down to 4.97 therms per degree-day. This compares quite favorably with the rate at which they were burning gas when we first started working on that system in the fall of 2005, which was 7.8 T/DD (a reduction of 36% from that figure) and with the rate of 5.3 T/DD at the end of last season (a reduction of 6%). Note that these figures also include domestic hot water which is relatively constant month-to-month and year-to-year. I doubt very seriously whether greater savings would have been possible by converting to hot-water, especially when you figure in all the disruption to the building, drilling holes, patching holes, etc. etc. etc.

    The other thing is, it IS possible to achieve 90+% steam boiler efficiency. Hot-water boilers do NOT have a monopoly on high efficiency. Hoval does it in the U.K. and Gasmaster does it in Canada, and those are just the two I know of- there are probably others I haven't had time to search out yet. Yet the ONLY American boiler manufacturer that has made any advance in steam-boiler efficiency is Burnham, which deserves much credit for doing so. 86% AFUE is a good start, and the Mega-Steam will take its rightful place as the present steamer of choice (especially if they offer it with a gas burner), but the millions of steam systems in America demand more-efficient steam boilers. The silence from ECR, Mestek, Peerless, Weil-McLain and others on this subject is positively deafening. Maybe when I get rich I should buy a boiler company and bring some of these things to market ;-)

    We need to keep pushing for higher-efficiency equipment on steam as well as hot-water. High-efficiency steam boiler technology exists, let's get it into steam-heated American homes.





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  • Rick_65
    Rick_65 Member Posts: 4
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    Here's the proof

    ASHRAE study changing steam boilers and cast iron water boilers to condensing boilers. No building improvements and no change in the controls scheme. Avg of 68% over steam system and 49% over cast iron boiler water systems.
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
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    I think not

    This appears to be the same article Ruhnke tried to cite. It leaves important questions unanswered.

    From my earlier post:

    "what condition were the steam systems in before (they) converted them? Also, what problems did they encounter?"

    It does say that at least in some cases, the existing steam boilers were started and stopped MANUALLY. That alone blows the comparison out of the water (no pun intended) since the new hot-water systems had up-to-date, functioning controls. But no mention is made of problems with existing boilers and burners, inoperative zone valves, bad traps, missing insulation and other things that would reduce the efficiency of the existing steam systems. So the too-good-to-be-true numbers they try to foist upon us mean little, if anything.

    It is also a valid point that many of the systems in question were located in schools. Anyone who has worked on school heating systems knows they are typically neglected until they fail completely. I'd bet money that the steam systems were near the point of total failure, certainly not operating at peak efficiency.

    Which brings up another point: If the steam systems suffered this kind of neglect, how will the hot-water systems cope with it? Especially the mod-con boilers? It would be interesting to go back there in a few years and see what's going on. I'd bet they have serious problems from poor maintenance.

    There is also no mention made of what happened when they pressurized the old piping and radiation with hot water. It's hard to believe nothing leaked, but since they avoided the topic we'll probably never know.

    This report has more holes in it than a Swiss cheese. It would be interesting to see who actually funded it. I see it as nothing more than a piece of puffery intended to stimulate mod-con sales. Now, I'm not against mod-cons, but this is not the way to promote them.

    When my company quotes savings figures, we can tell the whole story: this is what we did, this is how much was saved, these were the problems that came up, this is how we solved them, and nothing is hidden. We respect all of you way too much to do otherwise. I expect nothing less from industry organizations, ASHRAE included. ASHRAE ought to be ashamed of itself for allowing such an unscientific puff piece like this to see print.

    John, keep your steam. Have Matt take a look at it.

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  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
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    Was the steam system working

    as well as it could?...Who underwrote the study? I suspect a bias against The Steam.

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  • Uni R_3
    Uni R_3 Member Posts: 299
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  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
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    What type of system

    was the MZ in question installed in? What was the maximum design water temperature? Did they actually reach that water temperature during testing? What type of controls were used?

    Uni, I know it looks impressive, but...... we need to know the rest of the story.

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  • Uni R_3
    Uni R_3 Member Posts: 299
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    Not so much on the MZ side of life...

    More the loss in overall efficiency of conventional boilers as the outside temperatures rise. That's where the savings on a condensing boiler are the highest.
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
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    OK, so

    where is the chart showing the conventional boiler's performance? The MZ chart would mean much more if the conventional boiler chart was there to compare it to. And of course we'd want to know what model the conventional boiler was.

    And I'd still want to know the details of the system used in the tests. This would establish that the boilers performed in this way under these conditions.

    Remember, Gordo and I are the guys who "tested" the Gerber Viper toilet in our shop before we recommended it ;-)

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  • Uni R_3
    Uni R_3 Member Posts: 299
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    The blue line...

    The blue line represents the efficiency of a conventional boiler as the temperature increases. Obviously, it will go down as the temps rise, but how close is this graph to reality?
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
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    OK, I see the line

    and now that I've looked at the main Web page, I see that the two asterisks denote the curve for the conventional boiler, but they still don't tell you anything about system design other than this:

    "Note: This chart portrays the fuel use of a typical standard fin-tube baseboard heated residential system, presuming that the conventional cast-iron boiler is perfectly sized according to the IBR method."

    or anything about the conventional boiler used for reference, on the site:

    http://www.energysmartcanada.com/monitor.html

    If you have a way of finding this out, please do so. I'm sure everyone in this thread would like to know. It's hard to say how realisitic the chart is until we know how they arrived at the numbers we see there.



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  • ScottMP
    ScottMP Member Posts: 5,884
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    Steamhead

    87 % is great for a buner to be at, just how well does that energy transfer to the rooms ?

    Heat water to 140 in a small S.S or aluminum block. How much energy did you use to do that ?

    Now heat a big block of cast iron with a 6/7" flue in an atmospheric boiler. How much energy did you use ?

    I don't need charts to know that.

    Helping some one who can't afford or dosn't want to change their systems is fine. Saying its just as effecient as a 95% mod/con and that zoning and reset dosn't matter, dosn't make sense to me.

    Just how much did you charge those people to make all those "corrections" ?

    I have a friend who has a 1957 T-Bird, thats neat also. He dosn't use it everyday.

    We're all here to agree to disagree ... I don't see it.

    Scott

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  • Dave Yates (GrandPAH)_1
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    circle the wagons

    We're in the market for a new car. Mileage is an important consideration. The Prius is on my list, but I read an article regarding the stated mileage claims that was, shall we say, unflattering. I'd looked at it on-line, which led to a local dealer contacting me by e-mail. So, I replied back and asked them two fairly direct questions regarding what I'd read. Instead of answers, they have replied back with ad fluff. Having been ignored for two weeks, they finally got around to asking if I’d made a buying decision and was there anything else they could do to help? "Sure is - answer my original questions." The silence has been deafening!

    My point is this: we’re all missing the point! You can generate charts and graphs till the cows come home but, just like the EPA mileage guestimates, it’s how you drive the car – or boiler – that will determine the outcome. And, that’s where we sell ourselves so short in this industry, IMHO. The skills we bring to complete the picture – building the system – determine the final efficiency, or mileage rate.

    We’ve all see hi-eff products installed in such a manner that we know their final eff is sub-par. Yet, there’s an energy use sticker on the furnace, boiler, water heater, etc, appliance that tells the consumer what to expect.


  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
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    The amount of water to be heated

    is the factor that balances this out.

    Take the Mega-Steam 629. This boiler has a Net rating of 151,000 BTUH or 629 square feet. The water content of this boiler, according to Burnham, is 24.1 gallons when filled to the waterline. Aside from whatever is in the wet returns, or false water line or feed tank (if used), this is the only water in the system. Period.

    Looking thru some of my mod/con literature, I find water contents from 3-6 gallons. But that is not the total amount of water in the hot-water system that must be heated- the total could easily be 20-30 times that, depending on how the system is piped (and we can lay out a system and figure its water content if we wish). So there is much less water to be heated in a steam system than in a circulating water system.

    Then there is the number of BTUs that a pound of steam can move as opposed to hot-water. A pound of steam can move 970 BTUs, but a pound of water is far less capable and depends on the system's delta-T. I'll be generous and assume a 35-degree delta-T, which gives water a carrying capacity of 35 BTUs per pound. BTW, a pound of water is roughly equal to a pint.

    So if we have a load, say, of 151,000 BTU per hour, we can move that number of BTUs with 155.7 pounds of steam, which we can make with 155.7 pounds of water or about 19.5 gallons of water in a Mega-Steam 629 if my math is correct. With hot-water at a 35-degree delta-T, we'd need to move 4314.3 pounds of water, or about 539.3 gallons if my math is correct. That's 27.7 times the amount of water to be heated in a hot-water system as opposed to a steam system.

    Another factor is that the electricity used to operate hot-water circulators adds to the cost of operation. In many major metropolitan areas, electric rates have or can be expected to double or triple in the next few years as greedy, unregulated utilities continue to stick it to us. Though circulators are certainly getting more efficient, they still need ever-more-expensive electricity to run. If the steam system is gravity-return, it needs no pump at all. This shows another advantage for steam- fewer moving parts.

    More important than the cost of the job is the return on their investment. Where else do you find 36% ROI these days? And even if one could show a marginally higher overall system efficiciency, the ratio of investment amount to ROI would not be nearly as good.

    And I know your buddy's T-bird is pretty easy to fix if it breaks down.

    "Steamhead- El Capo del Vapore" (couldn't resist, Brad)

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  • Mark Hunt
    Mark Hunt Member Posts: 4,909
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    Yes.......but


    you HAVE to make steam every time the boiler fires AND the boiler will fire at full linear bore. Doesn't matter what the actual need is, the boiler is "floored".

    I wish this discussion were happening at a Wetstock where we could all sit face to face. This way there would be no chance of misinterpreting what someone says/types.

    Keeping that in mind Frank..........

    Do you or would ever offer a steam system to a person building a new home? Would you tell someone that a new steam system is as efficient as any other system available?

    Full disclosure here.......I have not torn out a steam system in over 20 years. The few that I did happened when I worked for a forced air company VERY early in my career.

    Mark H



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  • Uni R_2
    Uni R_2 Member Posts: 589
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    It's not steam that's inefficient, it's the boiler...

    "So if we have a load, say, of 151,000 BTU per hour, we can move that number of BTUs with 155.7 pounds of steam, which we can make with 155.7 pounds of water or about 19.5 gallons of water in a Mega-Steam 629 if my math is correct. With hot-water at a 35-degree delta-T, we'd need to move 4314.3 pounds of water, or about 539.3 gallons if my math is correct. That's 27.7 times the amount of water to be heated in a hot-water system as opposed to a steam system."

    Both are still netting 151,000 BTUs of heat into the envelope. The difference in efficiencies is the heat that leaks up out of the flue and other losses of converted heat that don't add anything inside the envelope along with missing the opportunity of converting more heat through using combustion right into the condensing range.
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
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    Regarding

    "AND the boiler will fire at full linear bore. Doesn't matter what the actual need is, the boiler is "floored"

    Not necessarily. If the steam boiler has a lo-hi-lo or modulating burner, it will mimic the old coal fire and tailor the steam output to the load, just like a modulating hot-water boiler. We switched a (significantly oversized) W-M LGB on a large Broomell system to lo-hi-lo with a switch point of 2 ounces and the owner reported a 40% savings on his gas consunption.

    "Do you or would ever offer a steam system to a person building a new home?"

    Done it! The home was being gut-rehabbed. We (my old company, that is) built a new one-pipe steam system from scratch, starting with a full heat-loss calc. The home was insulated anfd weatherstripped to the hilt and had all new windows, so the system was "right-sized" from the get-go. I don't have access to their fuel-consumption records, unfortunately.

    In any situation where there is a significant chance of an extended power or fuel interruption, a steam system is a natural fit because it won't suffer the same extent of freezing damage that a hot-water system will (OK, we can add antifreeze to a hot-water system, but that introduces cross-contamination, maintenence and environmental issues). As our energy situation deteriorates, this will apply to more and more parts of the country. We've all been thru hot-water system freeze-ups- they aren't pretty. So the "life-cycle costs" of steam systems are reduced because they would suffer much less damage in this situation.

    Speaking of life-cycle costs, which are an integral part of the overall efficiency question, a cast-iron boiler can be expected to last over 20 years with proper care. Some people say a mod-con will probably not last nearly that long. If a mod-con is installed in a low-temp system where it condenses all the time, it might recoup enough over its allegedly shorter lifespan to offset the cost of another mod-con and the labor to replace it again. Time will tell and we're watching.

    So yes- there are situations where steam would offer lower cost of ownership.

    And, if designed properly, a steam system (in a small building, that is) can be built with just four moving parts. Two air vents, a pressure limit control and a low-water cutoff. I think that's an all-time low in today's world, and certainly makes for greater reliability. Using TRVs would increase the number of moving parts, but that is true for any system, and the energy savings would justify them.



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  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
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    Ahhh, but

    you're heating less water. In the above example, the steam system is only heating 19.5 gallons of water. The hot-water system is heating 539.3 gallons- albeit to a lower temperature- and then it has to pump the water.

    So which takes less energy to do?

    I don't think there's much difference when you factor everything in.

    Gotta run- we just got a blown water heater call.

    "Steamhead"

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  • Wally_3
    Wally_3 Member Posts: 1
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    keep your one pipe steam

    A lot of posts already - here's some thoughts from a homeowner with single pipe steam.

    Who said to replace your steam with hot water? I'm betting it was the "inspector" who did the inspection prior to the house sale? Not to speak ill of them, but they all have their own pet peeves so you shouldn't assume that every recommendation they make is worth following.

    After you put in new windows and insulation your radiators will be over-sized. So what?

    Listen. In any room, the radiator was designed to match the heat loss from that room on a "design day" that represents something close to the worst conditions (or at least the worst "normal" conditions). So, the radiator was sized so that it could keep up on a windy, bitterly cold night in February. At Thanksgiving, when it is 45 F outside, the radiator is oversized. On anything but the coldest days of the year it is oversized. No big deal.

    What will have an effect on your system is whether the loads in all rooms change by about the same when you put in new windows and insulation. A room with two outside walls and four windows will very likely see much more improvement in heat losses than a room wiht one outside wall and one window. This will tend to unbalance the heat. Some rooms will be too hot while others might be too cold. To remedy this you (or a good steam-head) has to choose proper sized vents for the radiators to make it all work. Once in a while this doesn't work sufficiently. In that case, thermostatic vent valves can be installed (I put them on all of my second floor rads and they are great). You need to replace the vents on your system anyway - they don't last forever and it is a safe bet that the previous owner didn't do it.

    As far as your fuel bill is concerned, switching to hot water isn't likely to save you much. All other things being equal (which they rarely are) the boiler (whether steam or hot water) has to replace all of the BTU's (all of the heat energy) lost by the house. If your boiler and radiators are over-sized, then the boiler might run for 15 minutes and then be off for 45 minutes. If you re-sized your radiators (whether steam or hot water) and put in a smaller boiler, your boiler would need to run longer - maybe on for 25 minutes and off for 35. Either way, over the course of a day the boiler has to replace all of the heat lost so there is little savings in going to a smaller boiler versus a bigger boiler.

    Of course, there are some subtle differences and you might realize a small savings on a smaller boiler - but a boiler that is 25% smaller will NOT be 25% cheaper to run. Mostly, it will just run about 25% longer.

    Some might argue that a big steam boiler takes more heat to warm up and that this heat is wasted. This is maybe true, and maybe not. In my house, the heat from the boiler and whatever exposed piping (it is mostly insulated) is the only heat source in the basement. We do laundry down there and the kids watch TV and play nintendo in the basement - so for me this isn't wasted heat. If the boiler wasn't heating the basement I would have to add radiation in the basement.

    As far as space in the basement goes you will save a bit of space. It hardly seems worth $15,000 - $30,000 to get a few additional square feet in the basement. Two years ago I added a master bedroom and bath for $30,000. You could replace the old steam boiler with a new steam boiler for much less and save almost as much space. This is particularly true if the old boiler was converted from coal - these are big. You would also save more space if you change from oil to gas and get rid of the oil tank.

    There are some good things about hot water and if your system was completely falling apart, I would recommend hot water. Hot water allows for more options, more easily. By the way, in-floor radiant, especially under tile, is awesome. You can do more zoning with hot water, but with thermostatic vent valves you can do ALMOST as well with steam. A really well-designed hot water system (with outdoor temp reset) would be more comfortable because the heat would be more even. The best, most comfortable, heat doesn't cycle - it is even. You can't do that with steam - steam is either on or off. But a run-of-the-mill hot water system will cycle - you don't get the improvement unless you put in a more sophisticated system.

    20 years ago, the home inspector recommended to my wife and I that we replace the old, oil-fired boiler with a new gas boiler and that we put in hot water heat. My father - in - law, who was working at that time as a building code inspector in PA, told us that we should rip out everything and but in baseboard electric. I asked the inspector why. He pretty much said that the system was old, oil is dirty and that gas was "better." The system was, and is, old - and now, so am I. Oil is not dirty (unless you spill it on yourself) and since he never qualified "better" I have no idea if gas is better. On averge, gas has been more expensive than oil although right now gas is, I think, cheaper than oil. I didn't even bother asking my father-in-law for his explanation.

    So, I kept my old converted-from-coal-to-oil-fired-boiler. I adjusted the pressure on the boiler (learning the design pressures for the system from Dan's Lost Art book was worth the price of the book itself - no worth 10 times the price of the book - just this one little thing!). I replaced my vents and put in thermostatic vents on my second floor rads. I replaced windows in most of the house. I put a second vent on a troublesome radiator. I am perfectly happy with my single pipe steam.

    Anecdotally, my fuel bills are less than those of my neighbors. Not a lot less, and it is hard to tell how much is due to my temperature settings and my new windows, but the point is that with an old system I'm doing pretty well.

    Put in new windows and insulation and tune up your steam system or get a good steamhead to tune it up for you. Buy Dan's book. In fact, there should be a law that any home with steam heat must have a copy of Lost Art. Good luck.

    Wally
  • Christian Egli_2
    Christian Egli_2 Member Posts: 812
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    Keep steam if you have it. You're lucky.

    In total frankness, the proper maintenance of any home and the proper operation of any heating system will produce costs for comfort that mostly should be similar, but there are tiny differences... one often bandied around is that hot water heats a home with more efficiency than hot air does. The difference is tiny and in abstraction it is very true. So far so good.

    Well, if you all agree that hot water is more efficient than warm air, then work your mind around the next comparison and you'll find it beyond reasonable doubt that hotter yet steam works with even more efficiency than the hot water or either the warm air. It is all very obvious.

    All this is also only partially related to what goes up the flue, if the chimney were the only source of all our efficiency problems, then hot air should always - which it is not - be the hands down winner: large temperature gradient on air and lowest possible operating temperatures for maximum condensing... and yet, the oldest steam system like Wally's above outdoes all this.

    My personal experiences in buildings with hot air, hot water and hot steam have been revealing to me. This includes one building whose perfectly good system was half converted to water, all done super professionally and at the greatest cost. Watching the converted hot water side drown itself in massive energy inertia inefficiencies leaves me in distress. Light footed steam is always there with just what's needed and just on time. Nothing wasted. (This of course does not mean a properly designed hot water system won't work, quite the opposite. Neither does it mean steam is always perfect; there are many solutions to many problems within which electric ceilings and forced air furnaces are often just the right thing.)

    You don't believe me yet?

    Today, as we speak, the steam cycle is massively being installed everywhere - everywhere - and we never doubt it's efficiency and effectiveness: the air conditioner, the heat pump and the geothermal connections all operate on the vapor cycle we all believe in so strongly. It's all just a boiler, a condenser and a thermostatic trap, just like in the old powerful steam mansion. What's the secret to super SEER efficiencies? Smart thermostatic valves and oversized evaporators. What's the secret to steam heat efficiency? Thermostatic traps (vents) and boilers with sufficient heating surface for the fire. Exactly nothing new.

    Big old radiators simply had some difficulty making it through the Jetson age where we were supposed to all wear tin foil suits. Smash the fish bowl helmet and it becomes actually quite comfortable sitting by the radiator. Or smash anything that's just old. Moving away from the TV set also helps.

    ^ Just examples

    Steam and a comeback? It never left. Industrial uses scream steam efficiency. The city of Nashville just recently added a district steam system. In Nashville also, the cavernous Opryland Hotel is snaked with huge steam pipes. Chicago's new McCormick Place is steam. Note, old phase one is steam, phase two is hot water and now phase three is back to steam, hmmm... The city of Paris figured low temperature water loops would be the future back in 1984, grand expansion schemes were plotted, a test subdivision was built and... the futuristic thinking quickly withdrew back to steam. The idea ended in 1996 with a re-conversion to steam. Of the 435 kilometer of growing steam pipes below Paris, there is only 2.8 kilometers left of the warm water. Hmmmm... Paris has been doing it for 80 years, New York has been at it much longer. New York is steaming hot.

    ^ Just numbers

    How many hot water installs are put in every day? not many. How many steam installs? even less. Does it mean either one is bad considering we put in so many combined AC and warm air systems every day? Absolutely not. Another thing that is for sure is that trying to expand the hot water market share by nibbling away at the steam sector is no way to open up huge fields of opportunities, rather, it is a self destructing gamble that opens the trap for bitter resentments on conversion jobs gone bad as most do.

    Success is found in decoupling the patched up furnace of the combined heating and cooling schemes. Two tasks that have nothing in common and benefit greatly from being handled each as a separate design. Winter steam plus summer AC for dehumidified air is the winning combo in my book.
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