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need ideas for steam to gas hot water heating system using mod-com boiler

fenkel
fenkel Member Posts: 135
edited March 2020 in Radiant Heating
I need a cost effective boiler and setup for converting a old steam system to hot water using the existing radiators and piping. current steam system is a two pipe system..
I have done several by removing all the old steam system and replacing system with pex for pipes, fin tube for omitters and mod-con boilers for heat source and use indirect water heaters. But cost are very high..
I do a heat loss calculation and size boiler accordingly, I have been using indirect water heaters, but this has added about $1500 to $2000 to my costs.. so been pondering the use of a combi boiler. (water temp of incoming water is 38 degrees during the winter months...)
I can't use a non mod-con boiler, because the home doesn't have a chimney.
- Would want to be cost effective at the same have a reasonable longevity with the system..
-house is approximately 1100 squarefeet, three bedroom and one bathroom,
so i would plan for up to six people using bathroom ..
Any thoughts woulds be helpful..
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Comments

  • Steamhead
    Steamhead Member Posts: 15,342
    Don't do it. If there are any weak points in the piping or radiators, the fact that hot water needs over 10 times the pressure of steam to operate WILL cause leaks at these points, which you will then be responsible for fixing. Our company won't touch a system in this condition.

    Also, sizing the boiler is not enough. Since hot-water radiators can only give off 2/3 the heat of steam ones, it's quite possible they either 1- won't heat the rooms properly or 2- will need water above condensing temperature for much of the season.

    Your best bet is to fix the existing system. If the radiators have traps at the return connections, this is a Vapor system, which was the Cadillac of heating in its day and is still one of the best out there.

    Where is this system located?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    mattmia2
  • mattmia2
    mattmia2 Member Posts: 5,534
    Where was the old boiler venting if there is no chimney?

    You would have a hard time making enough hot water with a combi or tankless at 38 degree incoming water(although it is possible if you are ok with around 1-2 gpm and you have a large heat output of the boiler). Even with an indirect look carefully at the first draw tables(especially look at what boiler output that rating is for), you might need a much larger tank than you would think.
  • hot_rod
    hot_rod Member Posts: 16,320
    Also consider panel rads instead of fin tube for the conversion, lower operating temperatures are possible.

    On the domestic side, most combis are rated at a 77° rise, so that cold winter 38° would lift to 115°, plenty for showering etc. use a dishwasher with a boost feature for 140F at that appliance.

    Depending on the efficiency of the home, you may have a very load heat load, 25K or less. But 120- 150,000 for the DHW side.

    1 temperature system, TRVs on all rads, a buffer may be an option to lessen cycling on load load days.that has some mass.

    Some ideas here for lowering SWT retrofits.

    https://www.caleffi.com/usa/en-us/news/ushering-25th-edition-idronicstm
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    mattmia2
  • fenkel
    fenkel Member Posts: 135
    City provide the steam, so no boiler in home.
    City has sold out their interest to a bigger power coop.they decided to shut the boiler down..
    Location:northern minnesota.
    All residents have to convert..
    My heat loss was 64k btus at coldest day..
    Would be using an 80k boiler and adjust the output down to about 85 to 90%..
    Would be using an indirect water heater with around 45 to 50 gallons..
    Hot rod..ive given some thought to panel rads, but price point is high .. im not using any kind of a manifold, so the rads are in series..
    Most of the other contractors are using the existing system and then hooking up a boiler to it.. most are using combi boilers..
    Bosch, Navien, Lockinvar seem to be the most common boilers used.
    Ive seen a few htp ufts, but heard that they are discontinued. Also noticed some westinghouse boiler from menards..
  • fenkel
    fenkel Member Posts: 135
    Hotrod. I have a hard copy of the link you posted called idronics..
    Refer to it often..
  • mattmia2
    mattmia2 Member Posts: 5,534
    I don' believe the HTP UFT is discontinued but @Ironman would know. It is a good and inexpensive boiler if applied correctly.

    You're going to get much better efficiency with something like panel rads or radiant baseboard that you can design to work at lower temps. Fintube is cheap to install but usually isn't very efficient to run.

    Panel radiators with diverter valves that direct some flow to the radiator and some through the loop maybe with TRV actuators is an option to avoid home run piping.

    There are numerous panel radiator piping options.

    Getting a vent up through the building and installing a steam boiler still might be the most economical option.
  • fenkel
    fenkel Member Posts: 135
    Mattmai2...
    My locally distributor for htp states the uft has been discontinued and replaced with the elite ultra..
    Its not a firetube boiler..it uses the goavoni( sp) stlye of heat exchangers. They claim to have increased the size of the tubing in exchanger...supposed to reduce plugging that hampered the old munchkin boiler..
    Also htp was purchased by a firm from europe, trying to get a market foothold here in the states.
    I likethe htp uft boiler, installed over 25 of then last year.in fact have one on my current home and have solar worked into it for heating domestic hot water...
    Gotta say that out of the box, the htp had alot of features on programming that made installs easy..
    Plus, most needed almost little to no gas adjustments to get them to operating specs..
    And the techs have been for the most part pretty good.
    Like others have stated, read and follow the instruction in the manual..
  • Steamhead
    Steamhead Member Posts: 15,342
    mattmia2 said:

    Getting a vent up through the building and installing a steam boiler still might be the most economical option.

    Or sidewall venting using a power venter..........

    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    mattmia2
  • mattmia2
    mattmia2 Member Posts: 5,534
    the uft has a 10:1 turndown ratio, the eft is 5:1. I'm not sure i see what features you get for roughly twice the cost.
  • fenkel
    fenkel Member Posts: 135
    Which manufactures make steam boilers that can be vented thru the wall?
  • fenkel
    fenkel Member Posts: 135
    Heres the sales brochure for the replacement to the htp uft boiler.
  • Steamhead
    Steamhead Member Posts: 15,342
    fenkel said:

    Which manufactures make steam boilers that can be vented thru the wall?

    Burnham has the Independence PV. But pretty much any boiler can use a power-venter. Just make sure you have a proper sidewall venting location that meets Code.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    kcoppmattmia2
  • fenkel
    fenkel Member Posts: 135
    Ill have to check with the inspector on these.... Not sure that they will allow you to use internal air for make up...
    They're dam heavy as well.....
    wonder if you can brake them down to haul in?
    Stairs might be a huge issue moving these in..
    i also think they have a minimum afue % to get city financing..
    ( could be a deal breaker )
  • HVACNUT
    HVACNUT Member Posts: 4,594
    Look up the Energy Kinetics EK- 1 Frontier gas. Non condensing but should be acceptable to the board for its efficiency. See BNL testing.
    One option is sitting the boiler on a suppled pedestal with a 40 gallon water heater underneath.

    From what @Steamhead wrote though, steam to water sounds scary if you don't replace all the piping.
  • fenkel
    fenkel Member Posts: 135
    Not sure on the Energy Kinetics boiler.... would have to see one in action...
    Again, these appear to be quite heavy,
    What about cost and parts availability?
    The previous owner of my HVAC business would always say
    " why buy caddies when fords will do"
  • mattmia2
    mattmia2 Member Posts: 5,534
    Any steam boiler is going to be pretty heavy.

    The power venter gives you a lot more boiler options, I thought of that after my comment about might be cheaper to add a vent up through the building. The first part is to find out what their efficiency spec is. Converting to hot water or replacing the heat emitters is going to be enormously expensive.
  • fenkel
    fenkel Member Posts: 135
    Your correct on expense to replace pipe and basboards, but the condition of pipe is at best fair..
    Ive done mostly compete removal and replacements of existing ,using modcons..
    Ive tried to put a slant fin power vent unit into a place, put getting into the basement was a nightmare.. couldnt make the turn on the landing.
    I even brought a powered stepping two wheeler to get it in..still had to take the boiler apart to get it in.
    Im limited in manpower..have just 4 employees and parttime office staff.
    2 of my techs just do service calls.
    ( mostly rental maintenance).
    That leaves 2 to install and i try to be there as much as possible, but have to do sales and client relationships..
    The reason ive started thus chat is/was to get some good imput on how to do it and do it right and at the same be cost efficient to both me and the home owner..
    I understand that it would be best to replace the whole system, but thats expensive.. these system need to be price point systems..
    Ive been giving some thought to doing a system for cost and try to use the existing rads and piping...

    I might just pick up a westinghouse boiler from thebig box store and try it.
    Id do a p/s header and then do a room by room heatloss verses what the the current rad can put out and see what happens..
    I was surprise to find a version in a navien boiler manual on line..
  • Jon_blaney
    Jon_blaney Member Posts: 273
    How about some kind of external boiler room addition.
  • mattmia2
    mattmia2 Member Posts: 5,534
    Hiring movers to move the boiler in to the basement could be part of your quote.
    Canucker
  • hot_rod
    hot_rod Member Posts: 16,320
    Are the steam radiators a single connection? Sections connected across the top? Them may not work on forced hydronic for both Steamheads reasons and flow passage.

    If you are considering reusing the steam radiators, there are valves available to convert single opening radiators.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    mattmia2SuperTech
  • fenkel
    fenkel Member Posts: 135
    HotRod..
    system has two pipes, one on bottom of rad with a trap, and one on top for fill, top has a valve..
    see pdf for possible systems , which would work better?
  • Ironman
    Ironman Member Posts: 6,868
    If the UFT has been discontinued, it's news to me. They're still on the website for HTP and I haven't heard anything about discontinuing them.

    The UFT is a very popular boiler with a great price. I can't imagine that they'd be discontinued for the Elite which is much more expensive. And the Elite now comes in a fire tube version.

    Maybe your distributor is blowing smoke because they no longer carry the UFT?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    mattmia2
  • mikeg2015
    mikeg2015 Member Posts: 1,187
    Steam boilers aren’t “that” heavy. Got a 200k boiler into the basement myself using an appliance dolly. Just went one step at a time.

    83% vs realistically 93% for a mod con if you have to run higher water temps in colder weather. Plus the additional electricity for pumps and inducer.

    No frozen piping risk either.
  • fenkel
    fenkel Member Posts: 135
    Ironman, my distributor, place several orders with htp that wouldn't fill. My distrubtor states the elite ultra is the replacement for the uft boiler..
    He calims htp was purchased by a new group called Ariston..
    Even homedepot doesn't carry the uft
    Boiler any longer, homedepot now replaced it with the elite version..
    The elite ultra is not a firetube version.. the elite is...the elite is about a grand more in price and is only 5:1 mods..
    the real question is: why was it discontinued if its so good?
    We did alot of retros with them and they all have been pretty good.. even the gas adjustments where small..
    Only issue was one of the installs, we had too many elbows and had a condensate problem.. my installer used the old intake and exhaust system..
    ....anyhow.
    I really liked the price point on the ufts...
    mattmia2
  • fenkel
    fenkel Member Posts: 135
    Mikeg2015, they are heavy when your in your 60's and have been swinging pipe wenches for the last 40 years..even my installers are getting up there in age, ones 68 and still working.. he's good for about 5 hours aday, but spot on all the time.
    The main issue with putting in a steam boiler is, the homes have no previous boiler..long story short, the city had amain boiler that provided steam to over 1000 homes and businesses, even the schools where on the steam line..any how its just not a retrofit. Alot of radiators dont have traps. It appears the homeowners would use the rads as a trap, by only opening the incoming valve a small amount.. makinng the radiator hot at the top and cold at the bottom..as you feel acros the radiator it woild go from.hot to cold..kind of a "poor mans trap" even at the end of the hot steam line , a pipe would run from the ceiling in basemen to floor and then wouls attack to the return line..it woild fill with water..
    The steam would then head to a steam meter ( utility owned) and then run to the drain and out into the sewer system.
  • Steamhead
    Steamhead Member Posts: 15,342
    Basically a Tudor system. This is the simplest of all steam systems as it only has two moving parts, other than those on the boiler.

    From your posts, it sounds to me like you are not interested at all in anything except tearing out and replacing steam systems- true?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • hot_rod
    hot_rod Member Posts: 16,320
    fenkel said:

    HotRod..
    system has two pipes, one on bottom of rad with a trap, and one on top for fill, top has a valve..
    see pdf for possible systems , which would work better?

    Both are reverse return #2 uses less piping. Reverse return allows the system to be somewhat self balancing. the first radiator supplied is the last returned. So all radiators see about the same piping distance and near equal flow.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • fenkel
    fenkel Member Posts: 135
    Steamhead..
    No want to use as much of existing system as possible to convert to hot water boiler system.. just want to do it correctly...
  • Steamhead
    Steamhead Member Posts: 15,342
    In other words, the Caddy instead of the Ford as your old boss said.

    We've dealt with this before, where people push hot-water conversions, trying to say they're more efficient than a properly-operating steam system:

    https://forum.heatinghelp.com/discussion/145002/actual-savings-over-steam-heating
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • bburd
    bburd Member Posts: 332
    There used to be a small district steam system serving the far edge of West Philadelphia, from the late 19th century. The system was shut down and abandoned in the 1970s because the underground piping was old, leaking and too expensive to replace.

    Most of the houses got individual gas fired steam boilers. Since there were no chimneys, metal gas vent piping was run up the rear exterior wall, terminating several feet above the roof. This was before power venting was common.

    Bburd
  • fenkel
    fenkel Member Posts: 135
    steamhead, I'm not pushing anything on my clients. I started this form to learn more about using the old system and retro fitting it correctly.. I've only had one client ask for a steam boiler installation. all want a cheap conversion...
    The economy in the area is not that great, with the average age of a homeowners is almost 60. houses sell for as low as 40k, lots are the size of a postage stamp. If you lucky enough to have a garage in the back yard , its about 20 feet from the backdoor and it opens up almost on the alley. I have a hard time telling a client that i need 30k plus to do a system... Other contractors are using the old rads and pipes and still asking up to 14k.
    My father was an mechanical engineer and he says don't use the old system... do complete systems..
    That's what we've been doing..
    FYI:75% of the system used the old pipe system, about 10% switched to forced air/ ac system, heatpump, the rest electric, oil, propane boilers and complete retrofitts .
    So, why its wrong to learn more about this? I'm just trying to justify this to myself and to my clients..
    BillyO
  • Ironman
    Ironman Member Posts: 6,868
    fenkel said:

    Ironman, my distributor, place several orders with htp that wouldn't fill. My distrubtor states the elite ultra is the replacement for the uft boiler..

    He calims htp was purchased by a new group called Ariston..

    Even homedepot doesn't carry the uft

    Boiler any longer, homedepot now replaced it with the elite version..

    The elite ultra is not a firetube version.. the elite is...the elite is about a grand more in price and is only 5:1 mods..

    the real question is: why was it discontinued if its so good?

    We did alot of retros with them and they all have been pretty good.. even the gas adjustments where small..

    Only issue was one of the installs, we had too many elbows and had a condensate problem.. my installer used the old intake and exhaust system..

    ....anyhow.

    I really liked the price point on the ufts...

    IDK where you're getting your info, but I just got off the phone with HTP and I was told that the UFT is NOT discontinued and there are NO plans to do so.

    Their website still shows it available and so does HD's for the Westinghouse version.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    mattmia2
  • Steamhead
    Steamhead Member Posts: 15,342
    edited March 2020
    fenkel said:

    steamhead, I'm not pushing anything on my clients. I started this form to learn more about using the old system and retro fitting it correctly.. I've only had one client ask for a steam boiler installation. all want a cheap conversion...
    The economy in the area is not that great, with the average age of a homeowners is almost 60. houses sell for as low as 40k, lots are the size of a postage stamp. If you lucky enough to have a garage in the back yard , its about 20 feet from the backdoor and it opens up almost on the alley. I have a hard time telling a client that i need 30k plus to do a system... Other contractors are using the old rads and pipes and still asking up to 14k.
    My father was an mechanical engineer and he says don't use the old system... do complete systems..
    That's what we've been doing..
    FYI:75% of the system used the old pipe system, about 10% switched to forced air/ ac system, heatpump, the rest electric, oil, propane boilers and complete retrofitts .
    So, why its wrong to learn more about this? I'm just trying to justify this to myself and to my clients..

    First of all, we do NOT discuss actual prices on this forum. See https://heatinghelp.com/forum-user-manual

    Second, I agree with your father as far as conversions, but we replace steam boilers all the time with no issues regarding existing piping. So, how is a steam boiler installation more expensive than a complete tear-out and replacement?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    mattmia2Dan FoleyBillyO
  • HVACNUT
    HVACNUT Member Posts: 4,594
    Can I ask why, if everyone knew this change was coming down the pyke, wasn't there a plan in place? Is every owner on their own to figure out what to do?
  • fenkel
    fenkel Member Posts: 135
    Hvacnut, homeowners are on their own.
    steam might be turned off this fall..
    But do have a nice loan program for all that convert to gas...
  • EzzyT
    EzzyT Member Posts: 1,201
    @fenkel the UFT hasn’t been discontinued and as @Ironman has mentioned there in no plans of to discontinue the UFT boiler line.
    The Elite Ultra is 11:1 turndown ration not 5:1.
    BillyOmattmia2
  • mattmia2
    mattmia2 Member Posts: 5,534
    Perhaps there is some reason they are discontinuing Canadian distribution?
  • HVACNUT
    HVACNUT Member Posts: 4,594
    > @fenkel said:
    > Hvacnut, homeowners are on their own.
    > steam might be turned off this fall..
    > But do have a nice loan program for all that convert to gas...

    Can you provide a layout or blueprint copy of your apartment? Maybe we can help more if we can see more.

    If everyone is on their own, multiplied by X apartments, how many different designs and applications will there be?
    Again, it seems someone, the board, the city, the state, really dropped the ball as far as planning and coordination.

    Back when I did HVAC installations, condos, tract homes, strip stores, had 3 or four models. Left end, middle, right end. You could go into building 1, apartment 1 and find the exact same setup as apartment 1 in buildings 2,3,4...
    I'm out of my depth on your situation but as a service guy, I don't think I would like your building very much once 100 different contractors were in there doing their own thing.
    You're all under the same roof and things should be uniform.
    Easier said than done I guess.
  • PerryHolzman
    PerryHolzman Member Posts: 234
    How about you talking to the neighboring buildings and look at building a dual boiler steam system that supplies several buildings (you may need an outbuilding). I think that would be cheaper than converting every building individually.

    Perry
    HVACNUT
  • fenkel
    fenkel Member Posts: 135
    Perry, great idea..but surrounding homes and units have been converted from steam to gas...
    Over 1/ 2 of city residents are off the steam line now...
    Im.checking into steam boilers now, the first distributor will not carry them, the second said he doesnt carry them,but will check on availability.. both said very small market here..
    So up in the air now...