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    BEST WAY TO PIPE A 2 PIPE STEAM CONVERSION TO A 3 ZONE HOT WATER (16 Posts)

  • JEFF5255 JEFF5255 @ 10:41 AM
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    BEST WAY TO PIPE A 2 PIPE STEAM CONVERSION TO A 3 ZONE HOT WATER

    I'M LOOKING FOR HELP ON THE BEST WAY TO REPIPE A 2 PIPE STEAM SYSTEM TO A 3 ZONE HOT WATER SYSTEM. I DO HAVE 2 PIPE HOT WATER RADIATORS EXISTING AT THE HOME AND FROM PAST BLOGS UNDERSTAND THAT I WILL NEED TO REMOVE THE GUTS FROM THE EXISTING STEAM TRAPS. I'M AT THE POINT NOW WHERE I NEED TO FIGURE OUT THE BEST PIPING PLAN. I'VE HEARD THAT A REVERSE RETURN CAN WORK BUT A MONOFLOW SYSTEM WOULD BE BETTER. IS THERE ANY PIPING DIAGRAMS OUT THERE TO HELP WITH THIS??
    MY EMAIL IS janopolsky@24hrsinc.com
    THANK YOU
    JEFF
  • Steamhead Steamhead @ 11:07 AM
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    Best way

    is not to convert it at all- unless you like living dangerously.

    A conversion will raise the system's operating pressure over ten times. This WILL uncover any weak points in the piping and radiators, causing leaks which may damage the building.

    Also, any given radiator on hot-water will only give off roughly 2/3 of the heat it will deliver with steam. The ability to use smaller radiators for the same heat load was one of steam's many advantages. If you convert, you run the risk of not being able to heat the building during really cold weather.

    And if you plan to use a condensing boiler, it will not condense in all but the mildest weather, since you have to get the radiators so hot to provide any heat at all.

    Keep the steam and use thermostatic radiator valves. It's just as effective, and a LOT less risky and expensive.
    "Reducing our country's energy consumption, one system at a time"

    Steam, Vapor & Hot-Water Heating Specialists

    Oil & Gas Burner Service

    Baltimore, MD (USA) and consulting anywhere.
  • nicholas bonham-carter nicholas bonham-carter @ 11:11 AM
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    Hot water conversion

    What's wrong with keeping the steam?
    If you convert to hat water, your system could suddenly be exposed to pressures 30 times higher than those it was originally designed for, so a complete repiping will be necessary.
    You could instead concentrate on making the steam work properly with thermostatic radiator valves to control the heat in each room.--NBC
  • Jamie Hall Jamie Hall @ 12:12 PM
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    Considering that

    restoring a two pipe steam system to its original operating condition is going to cost a good bit less than any possible conversion, and that a two pipe steam system with thermostatic valves will do everything that a hydronic system will...

    And will do it, if you spring for a modern boiler, at an efficiency which is only slightly less than a mod-con with all the computer bells and whistles correctly applied and maintained....

    Why are you doing this?  It's going to cost you money which you will never get back.  It's going to take more maintenance.  Why?
    Jamie

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Jamie Hall Jamie Hall @ 12:14 PM
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    I might add

    that you mention taking the innards out of the traps.  It is quite likely that you will have to change out all the valves as well, as they may have orifices or throttling elements which are fine for steam but can't be present for hot water.

    Assuming, of course, that the radiators can take the pressure...
    Jamie

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • JEFF5255 JEFF5255 @ 7:35 AM
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    Why we are Converting steam to hot water

    Thank you all for your responses.
    I do understand the risks here and have conveyed them to the homeowner.
    I have to be honest about this job, I too have my doubts and reservations about taking this on but my partner is an ultimate optimist and always welcomes challenges. He's also a great salesman! At this point in time he has basically committed to the customer that although there are some risks, he assured him it can be done and we are the company to do it. So I'm basically trying to plan and deliver the job the best way I can.
    The reason we have agreed to take on this job as I described it was for a couple of reasons. 1. The customer just bought the house and does not want to heat with oil. The home currently has gas so he realizes immediate and long term savings by switching over. He is also energy conscious and figures if he's going to switch the he wants the highest efficient equipment. 2. The home is 3 stories and he is actually planning on renting each floor out as separate apartments and wants each tenant to have there own thermostat, i.e: the reason I'm looking for the best practice with the piping of the 3 separate zones.
    3. The home was built in 1916 and he wants to keep the original radiators to retain the original vintage look in home. He was not interested in baseboard which we offered as an option.
    Believe me I've already talked to my partner about walking away from this one but like I said
    He welcomes the challenge and has already committed to the sale.
    Before we start I plan on carefully reviewing all the possible "what if's" and possible challenges that are in front of us with the customer and if pipes and radiators leak under the new pressure there will be extra charges to fix them. (By the way, The 1st step we planed on doing was to pressurize the system and test for leaks before we start to check the integrity of the of piping and radiators an know upfront what we are dealing with.) I'm also doing a radiator load rating for hot water and comparing it to the heat loss calc to confirm that the radiators have the ability to handle the heating needs with the lower net output running on hot water rather than steam.
    So at this point we've basically got both feet in and if everything checks out I want to be sure to run my 3 new zones with the best practice for the new hot water zone so that it work best and every radiator works properly.
    Thanks again for your help!
  • moneypitfeeder moneypitfeeder @ 7:49 PM
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    I find this whole post disturbing...

    Hi, I'm a homeowner, who has been burned in the past by some well paid knuckleheads. After reading your reason for conversion, I have to say I'm at a loss. I don't mean to bash anyone here, however all I hear from your response is that you the steam pro, has not educated your salesman how to appropriately sell a steam job. If I were "your" homeowner, I would be terribly mad to read this post a year after the installation to find out I could have paid less to have my original system properly vented, insulated, & with new boiler(es), less downtime (probably than a new hot water conversion), no "new" expensive radiators, no possible floor/wall damage if any lines can't hold pressure...etc etc. I honestly think your best option is to have a conversation with your really great salesman, and tell him to fix this, and at least offer the homeowner the honest evaluation that his/her steam system can be made green, possibly greener than all the materials, upkeep, etc needed for a conversion. Just my 2 cents.
    steam newbie
  • nicholas bonham-carter nicholas bonham-carter @ 10:45 AM
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    Sales opportunity

    This would be a perfect opportunity to install 3 boilers, so each apartment could have its own.--NBC
  • Jamie Hall Jamie Hall @ 12:22 PM
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    Oh dear...

    Sounds to me as though your client might be a good candidate for buying this bridge I have for sale in New York -- cash only, of course.

    By the time parasitic losses in hydronic systems are taken into account, he will save almost nothing in terms of efficiency; if he were really "green" he'd stick with steam.  Which can be zoned very happily -- or as NBC suggested, use three small boilers, which would work even better.

    However, it sounds as though you have gotten yourself into a nice hole, and what is needed is a way to dig yourself out of it at with a minimum of damage to you and your company.  Which I can understand; I've had some very odd clients in my day as well.

    That said.

    In terms of prep work.  First, pressure test all your radiators.  Sell the ones that fail to a good steam man who needs them; fixing the leaks isn't going to be worth it.  Then drill and tap the survivors for air release bleeders and install them.  Find new or used matching radiators to replace the leakers.

    Replace all the valves with hot water valves; see if you can sell the steam valves to someone who needs them (particularly if they are any of the several vapour system valves!).  You can keep the trap bodies, but as you say, remove the guts. 

    I'd plan on scrapping all the old piping, even if it doesn't leak.  The odds of it being arranged to work three separate zones separated by floor are slim to none, and you might just as well do the whole thing while you're at it.

    Now.  I'm not a hydronics guy, so take my comments on this aspect with a large dose of salt.  I would pipe it reverse return, primary/secondary, with individual circulators for each zone.  Why?  I think it would be much easier to balance the heat within the zones that way using your nice new hot water valves.

    I'd also write a cost plus contract on this one; there are just too many booby traps in there.

    Good luck...
    Jamie

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Jamie Hall Jamie Hall @ 9:37 PM
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    Rereading the thread

    this evening, I completely agree with what moneypitfeeder has said.

    You have gotten yourself into a very bad position on this job -- certainly one which I would want no part of whatsoever.

    And I honestly and truly do wish you luck in digging yourself out of it, and hope it doesn't come back to bite you.
    Jamie

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Eastman Eastman @ 12:20 AM
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    zones

    how could the op efficiently zone the steam system

    trvs cant call for heat

    apologies for my failing keyboard
  • Eastman Eastman @ 12:25 AM
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    also

    some rads are not good candidates for conversion because they are not connected accross the top. i dont think that was mentioned but seems pretty important.
  • Eastman Eastman @ 12:27 AM
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    3 boilers

    why

    that seems like such a waste, can't see any positives.
  • ChicagoCooperator ChicagoCooperator @ 1:47 PM
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    Postive for Landlord

    It means that each tenant pays their own heat and the LL has less responsibility for providing it (other than equipment can do it). Agreed, though, it's a not a great idea. 
  • Eastman Eastman @ 3:14 PM
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    incentives

    if the renter pays, then there is no direct incentive to improve the efficiency of the heating system or building envelope.
  • EzzyT EzzyT @ 2:36 AM
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    Don't do the conversion

    I've had clientele in the past ask me to do that because they read some where or someone suggested to them that it could be done and those knuckleheads told them that steam is out dated and inefficient. Clearly those so called heating guys don't know jack.
    In the long run those clientele where not really ready for the cost and amount of work it would take to it. I suggested they stay with steam and spend the money to upgrade the system change some bad traps convert from oil to gas upgrade the main venting and insulate the piping. Won't you know they had one of those knuckleheads do the job and it done wrong exposed so many more problems for the homeowner. In the end the whole system had to be ripped out and installed from scratch and had to move out of there house while pretty much the entire house needed to be gutted. So as we all are saying huge mistakes to take on a job like that but good luck
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