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Help sizing for new Steam Boiler (replacement)

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Hello,

I am in the process of pricing out new boilers to replace my old Weil-Mclain EG50 steam boiler, currently rated at 142,000 BTU ouput. I feel that the current boiler is oversized and would like to purchase a smaller, more suitable boiler to my application.

It is a one-pipe steam system which currently has 7 radiators in the house and I have calculated the the sq. feet of steam as 240 sq feet of steam which multiplied by 240 gives me 57,600 BTU (76,608 with the pickup factor).

I am toying with the idea adding another small radiator which would add an additional 22 sq. feet of steam bringing my total to 262 sq. feet of steam and multiplied by 240 would give me 62,880 BTU (83,630 with the pickup factor).

The model that I was recommended is the Weil-Mclain EG35 which is rated as:
Maximum Input Capacity (BTU)100000 BTU
DOE Heating Capacity (BTU)83000 BTU
Net I=B=R Capacity (BTU)62000 BTU
Efficiency (%)82.9 %

Do you think this is a suitable choice or is it too much or too little for my needs? Any help/recommendations would be appreciated, Thanks!

Comments

  • KC_Jones
    KC_Jones Member Posts: 5,742
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    If you look up the ratings for those boilers there is a column that says Steam (sq ft) you compare that number to the EDR calculations you came up with. Unless you have some weird unusual system you compare these numbers directly no need to do the additional BTU calculations. I would say you are good to go on that EG 35, it's rated for 258 which is just a hair under your final 262 number, but close enough. The pick up factor is already calculated on those sq ft ratings.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • erobinson85
    erobinson85 Member Posts: 19
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    Thank you for the quick response KC! I have an additional question. I have attached a picture of my current boiler piping. I was told this was not a "true/traditional" hartford loop setup but does it make sense to make changes to the header setup? I will be replacing the current sections of copper (riser, equalizer, and return) with black steel pipe and insulating everything when finished. My thought is that since it has been this way, that it would make sense to keep it the same but with updating to black steel pipe instead of copper. Looking for any thoughts/recommendations as to what is the best way to do it.

    Thanks!
  • KC_Jones
    KC_Jones Member Posts: 5,742
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    You want recommendations on what "the best" is? Just to be clear there can be a fairly significant difference between "the best" and "enough". Since you are putting in a fairly small boiler the minimum spec in the Weil Mclain manual would most likely perform adequately...maybe. If you want to step it up the first thing you could do is up the pipe size. A single riser in the full 3" into a 3" header then the main takeoffs from there. If you wanted to go "over the top" you would use both tappings on the boiler in 2" and into a 3" header either standard header or a drop header. There are many options for this and it usually comes down to money and what you are getting for it. Are you doing the install yourself or are you paying someone? I can't make out everything in your current piping, but for my money I would tear it back to the mains and do it over. It will be cleaner that way and will allow you to lay it out anyway you want, otherwise you have to work around that header which could actually make it harder. Is there a radiator valve on the equalizer end of the header? I would also suggest redoing some of your return piping to add valves for maintenance. The copper below the water line isn't a problem and can actually help keep things cleaner. I am sure you will get other opinions on this. If you do any piping above manufacturer spec (highly recommended) and you are sized almost perfect (as you are) this should be a very nice system when complete.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • Fred
    Fred Member Posts: 8,542
    edited December 2015
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    What KC said and BTW, your Hartford loop looks fine as long as it enters the equalizer a couple inches below the normal water line, in the boiler. Not sure what was meant by it not being "traditional" ??
  • erobinson85
    erobinson85 Member Posts: 19
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    Thanks again for the quick responses. I will be assisting a plumber friend of mine with the install. I am new to steam heating and am trying to educate myself as best as possible so that I know what I am working with and how to best maintain it.

    KC, to answer your questions there is a valve at the equalizer end of the header. I do agree that a 3" riser is definitely the way to go. I know its not a great picture, I can try to post a better one later tonight. What would you do differently as far as the header goes? My initial thought was to try and change as little as possible, but if it would improve the functionality of the system I am open to whatever makes sense.

    Fred, it does enter the equalizer 2 inches below the water line. I'm not sure what was meant be not being traditional either so I was hoping someone could shed light on that. But if you say it looks correct to you then sounds good to me.
  • Fred
    Fred Member Posts: 8,542
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    The Hartford loop is fine. If it were me, I would take that valve off of the end of that header and put a plug in there, at a minimum. It serves no purpose and it is just a potential for some leaking at some point down the road. Eliminating that issue now makes sense.
  • KC_Jones
    KC_Jones Member Posts: 5,742
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    KC, to answer your questions there is a valve at the equalizer end of the header. I do agree that a 3" riser is definitely the way to go. I know its not a great picture, I can try to post a better one later tonight. What would you do differently as far as the header goes? My initial thought was to try and change as little as possible, but if it would improve the functionality of the system I am open to whatever makes sense.

    What is the valve for? I can't imagine anything that needs to be there with a valve?! Just to be clear I was outlining options on all possible scenarios and what Hat said is right on in your situation. Mostly it comes down to money and what you want to do. I go over the top right wrong or indifferent, it's the way I am. a 3" riser into that header wouldn't make any sense. If that existing header is indeed 2 1/2" then the biggest riser you should do is 2 1/2", 2" is minimum spec on the boiler you are installing. I will reiterate adding some valving on the low end for maintenance. If you haven't seen it yet here is a nice video outlining near boiler piping.
    https://heatinghelp.com/systems-help-center/near-boiler-piping-video/
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • erobinson85
    erobinson85 Member Posts: 19
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    I honestly have no idea why there would be a valve there, I thought it was a bit odd as well. I will post some additional pictures when I get home later and confirm the measurements of the header. I will also check out the video. Thanks KC and Fred.
  • erobinson85
    erobinson85 Member Posts: 19
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    KC, I just watched the video and have one additional question. They show the "King Valve" located on the main coming off the header. Since i have 2 mains coming off my header, would I need 2 King valves, one on each main?

  • KC_Jones
    KC_Jones Member Posts: 5,742
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    The king valves are an added extra, you don't necessarily need them. Some of us have them some don't. I think it's one of those things you might not ever need them, but if you do need them and don't have them....well you know how that can go. If you want them then yes one on each main. I only have one year of service with my new boiler and I have them, but haven't needed them yet. You might get other opinions. I am of the opinion that you almost can't have too many valves for servicing.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • erobinson85
    erobinson85 Member Posts: 19
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    KC_Jones said:

    The king valves are an added extra, you don't necessarily need them. Some of us have them some don't. I think it's one of those things you might not ever need them, but if you do need them and don't have them....well you know how that can go. If you want them then yes one on each main. I only have one year of service with my new boiler and I have them, but haven't needed them yet. You might get other opinions. I am of the opinion that you almost can't have too many valves for servicing.

    I took some additional pictures so that you can get a better idea of the boiler piping. (I forgot to measure the size of the header so I will do that tonight). If you can give me recommendations on a better way to route the header pipes that would be great.

    I also attached a better picture of the valve that is at the equalizer end of the header pipe. It actually looks like there is a both a relief valve and a radiator valve (not sure why) but if you think it is best to remove both and cap it off, I will do that.

    I had some additional questions about air vents. I currently have Hoffman 1a adjustable air vents on the majority of my radiators and I think it may be a good time to replace them since they appear to be pretty old and could use an update. Would you recommend staying with this type of valve or someone else recommended Gorton valves instead. What are your thoughts?

    Lastly, I have attached a picture of the air vent that is at the end of the longer of the 2 mains (the shorter main does not have one). Would it make sense to replace this at the same time also? If so, any recommendations?

    Thanks
  • Fred
    Fred Member Posts: 8,542
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    Your new boiler will have a tapping on it for the Pressure Relief Valve that comes with the new boiler. The exsisting Header looks fine, however I would remove that Valve and that old relief valve. It almost looks like some old Blow down mechinism, from days long gone. It serves no purpose today.
    Hoffman 1A vents are good vents and very reliable. They are convienient because thay are adjustable and you don't have to buy different sizes to accommodate radiator size/distance from the boiler. Some people say they click a lot but I haven't had that problem. The Gorton is a great vent also but you do have to size them. They are not adjustable
    That vent on the end of your main is way to small. The rule of thumb is the equalivent of one Gorton #2 vent for every 20 feet of 2" main. It takes about 3 Gorton #1's to equal a Gorton #2 and 15 to 20 of those that are currently on that main to equal a Gorton #2. The short main should also be vented. Vent anywhere after the last radiator run out off of the main or, if need be, somewhere on the dry return at the end of the main.
  • erobinson85
    erobinson85 Member Posts: 19
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    Fred said:

    Your new boiler will have a tapping on it for the Pressure Relief Valve that comes with the new boiler. The exsisting Header looks fine, however I would remove that Valve and that old relief valve. It almost looks like some old Blow down mechinism, from days long gone. It serves no purpose today.

    The short main should also be vented. Vent anywhere after the last radiator run out off of the main or, if need be, somewhere on the dry return at the end of the main.

    Thanks Fred I will take your advice and remove the valve and relief from the end of the main.

    Do you see on the fitting above the riser, there is another nipple sticking out that is capped off? Do you know what this might be for or if that should be removed also?

    Also, I have attached another picture showing the end of the shorter main, where would I put the vent on that side?
  • Fred
    Fred Member Posts: 8,542
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    I did notice that nipple and cap on the other end of that Header. It also, serves no purpose but I didn't mention it because it is capped and not hurting anything. You can take it off and plug that opening as well. Makes for a little neater job.
    On your short return, you probably need to replace that elbow with a Tee and reduce it down for the Vent and put a 45 on there so that the new vent is upright. Not too many options there.
  • erobinson85
    erobinson85 Member Posts: 19
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    Fred said:


    On your short return, you probably need to replace that elbow with a Tee and reduce it down for the Vent and put a 45 on there so that the new vent is upright. Not too many options there.

    I apologize for the hiatus, I have been away for the holidays. I have installed my new boiler and the system seems to be functioning very well so far, especially in the frigid temperatures that we've currently been having in NJ. I would like to still upgrade the main venting if possible. Fred, you mentioned replacing the elbow on the short main with a Tee in order to add the vent in that location. From what I can tell there is no "easy" way to get that elbow off, do you have any recommendations?

    Thanks
  • Fred
    Fred Member Posts: 8,542
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    Any chance of drilling and tapping that elbow to mount a vent? You might also be able to drill that short nipple just before the elbow and weld a Thread-o-let onto that nipple to mount a vent. Given the current cold spell, if it's heating pretty well, I would wait until the weather breaks to mess with the main/return.
  • erobinson85
    erobinson85 Member Posts: 19
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    Yeah I don't think I would be doing it anytime soon since it is working fine and I definitely don't want any down-time during this cold we're having. Drilling and tapping seems like a good possibility, so I would just drill and tap it to 3/4" to be able to attach a nipple to raise the vent up?
  • Fred
    Fred Member Posts: 8,542
    edited January 2016
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    That is correct. 1/2" may be enough if you don't intend to put more than 2 Gorton #2's at that location.
  • erobinson85
    erobinson85 Member Posts: 19
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    Thanks Fed. Another thought I had, would it make sense to drill and tap the top of the main itself instead of the elbow? I saw somewhere that the vents should be 15 or so inches back from the end of the main and the only way to do that would be to drill into the main itself.
  • Fred
    Fred Member Posts: 8,542
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    Ideally the vent should be about 15" or so from the drop to the wet return. You can drill the pipe but I'm concerned that the pipe wall may not be thick enough to tap it for the vent. That's why I suggested the Thread-o-let, if drilling into the pipe itself. So many of us have vent's at that elbow that I think you will be fine as long as you don't have a lot of water hammer, which can damage the vents at that location. I think you'll be fine.
  • erobinson85
    erobinson85 Member Posts: 19
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    Do you have any pictures of an elbow drilled with a vent attached?
  • Fred
    Fred Member Posts: 8,542
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    I don't but I'm sure others on here do. In my case, there is not an elbow at that drop to the wet return, It is a TEE and that is original to the house, which is 114 years old.
  • erobinson85
    erobinson85 Member Posts: 19
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    Oh ok no problem. Do you have a picture of yours that I could see just for reference?
  • Fred
    Fred Member Posts: 8,542
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    Take a look at this thread. It has a picture of a Hoffman #75 at the end of the main, on a TEE, where it drops to the wet return. Mine is set up the same way except I built an antler and have multiple 75's on it.
    http://forum.heatinghelp.com/discussion/155243/steam-heat-weil-mclain-boiler#latest
  • erobinson85
    erobinson85 Member Posts: 19
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    Got it, thanks! Is there a name for those types of elbows that have the 3/4'' outlet on them as well?
  • Fred
    Fred Member Posts: 8,542
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    They are just reducing elbows, 1-1/2 X 1-1/2 X 3/4 or 1-1/4 X 1-1/4 X 3/4 or whatever size you need.
    If need be, you can buy a standard Tee (same size at all three openings) and a bushing to take it down to 3/4"
  • Jamie Hall
    Jamie Hall Member Posts: 23,442
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    Sizing a steam boiler is remarkably easy, and you have already done part of the work. What you need to do is to find the "EDR" of each of those radiators, including the baseboard units, and add them up. That's your total EDR. The correct boiler size is the one with that EDR rating, plus or minus 10%. It is highly unlikely that that basement zone will need to be figured into the boiler rating, unless it is really big.

    Unless you are really handy, however, it is usually best to have a professional who is knowledgeable about steam heat do the whole job -- purchase, install, and start-up. That way you get a job where the installer knows and likes to work with the equipment.

    It is, however, essential that you find someone who knows steam heat. It is remarkably easy to take a fine boiler, correctly sized, and come up with horrible results because of a poor installation.

    You might try the "Find a Contractor" tab on this site, or if you tell us where you are located we may know someone who works in your area.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    mortgagemagic
  • Abracadabra
    Abracadabra Member Posts: 1,948
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    @mortgagemagic Posting this message multiple times will not help you get a better or faster response. I've refrained from responding because I've seen your message posted several times. All 5 of your first messages are the same exact message.
    mortgagemagic
  • BobC
    BobC Member Posts: 5,479
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    How high are those radiators and how many columns or tubes in each section? You need to know what the EDR of all the radiators is before you can select what size boiler you need. Is the base board in the cellar fed off a water loop from that steam boiler and is there a pump?

    As to cost we don't discuss pricing because of the wide disparity of labor rates across the country. That said what were they going to do besides replacing the boiler? Were they going to do any repiping?

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
    mortgagemagic
  • Jamie Hall
    Jamie Hall Member Posts: 23,442
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    OK. Fair enough. Take a deep breath and relax.

    First off, a leaking steam boiler does need to be replaced. Leaks do not get better with time. However, unless it is making a pond out of your basement, it is also not a do it yesterday catastrophe. If it still makes steam, you have time to do it right.

    The various pros who have measured the radiators are doing things the right way around. If you like, you might give use the actual height and width of all the radiators or, as I said in my post above, you can look it up and add it up.

    Also as I said above, the only way to properly size a steam boiler is to add up the radiation and base the size on that. The size of the house has nothing to do with it. Chances are very good that unless someone has gotten creative and removed radiators, you have enough.

    Now. We don't discuss price on this site -- as has been said, it's not fair to anyone. I will say this, though: some of the variation in price you are seeing may be variations in what the pro. is proposing to do. It is not always sufficient to merely swap out boilers -- these things aren't tires on a 2004 Honda Civic -- and some of the pros may have noticed other work which needs to be done. I wouldn't be surprised.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Erin Holohan Haskell