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Sizing up STEAM

NickM
NickM Member Posts: 25
I manage a 37 unit, 5 story, unit brick building built in the '40's.  The present boiler is a Weil Mclain 88 series with 9 sections (installed in the late 80's) controlled by a Heat Timer. I took a survey of the radiators and came up with 3400 sq ft of radiation. I also noticed that the steam pressure was reading 5 lbs this morning (if that means anything)

The problem is the apartments are too hot (some measuring in the high 80's) and we burn way too much oil.  I have had Heat Timer look at the system on three occasions  in the last two years and they say that the equipment  is operating perfect.  I have had six professional boiler guys look at  and installed many new parts and pieces.  This year three sections failed (rotted at the top) and we replaced them.  Two Pro boiler men told me to replace the boiler because the increased efficiency will pay for itself in two years.   Pro # 1 says the boiler is too small and we need a larger  unit.  Pro # 2 says the boiler is too big.

Help. please

What size boiler is correct ?

Is the efficiency that much better ??

Is there anything I can do to control the boiler I have ???? 

Regards

Nick

Comments

  • Charlie from wmass
    Charlie from wmass Member Posts: 4,314
    edited January 2011
    588 Weil if your size you stated is correct.

    and the system can use the standard pick up factor for you piping. The near boiler piping is critical with boilers as modern as the one you have. Also water should be tested for chemical composition as chlorides are linked to some boiler failures. The 88 can also have a dual fuel burner that fires either gas or oil depending on which will give you more bang for your buck that month.

    If height is an issue but length is not a 1080 Weil will also work.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
  • Rod
    Rod Posts: 2,067
    System Type

    Hi- What type of steam system is it- one or two pipe? Where are you located? As Charlie mentioned some areas have problems with chlorides in the water- notably south Boston for one.

    - Rod
  • Dave in QCA
    Dave in QCA Member Posts: 1,784
    WM 588 Rating

    The Weil-McLain 588 is rated for 3521 sq ft.  It is one of the most efficient Steam Boilers on the market.

    Premature Rotting of the sections can be caused by high chloride levels.  Some local water is higher than others, but no matter where you live, the level will climb if you are loosing steam or condensate.

    Also, it appears that in areas that are prone to high chloride problems, one approach is to get a larger than necessary boiler, but down fire it to the level that is matched to the radiation.  The high chloride problem manifests itself on boilers that have pins for aiding the heat exchange.  The pins just above the water line cause the iron to get excessively hot at that location, and the intense heat combined with the elevated chlorides in the water cause a reaction called graphitic corrosion.  It seems that when a boiler is fired at lower than design conditions, the pins at the water line to not get nearly as hot.



    As for your temperature control, it appears that you need to continue to tune your heat timer control.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,314
    You said you have a 9 section?

    That is rated 7358 square feet of steam unless the R model which is still over 6000. The boiler must be very down fired if the building is not getting bounced around when it tries to force all that steam into the system.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    edited January 2011
    37 unit steam improvements

    that pressure is much too high. for any pressure over a few ounces, the money spent on maintaining it at that pressure, goes straight to hugo chavez, and you know what he would like to do with the money!

    as i have said before, these heat-timer/tekmar controllers cannot compensate for a system with "deferred maintenance". i recommend the following steps:

    1.put on a good low pressure gauge [gaugestore.com 0-15 ounces]; with a pair of vaporstats [0-16 ounces]. the second vaporstat will control the hi-lo-hi on the burner.

    2.increase the venting of the system. put on enough large main vents [plus one] to reduce the back-pressure during the initial air removal to 2 ounces. set the vaporstat to go to low fire at 6 ounces. your risers may have vents at the top, or they may loop back down to be vented in the basement. the gauge will show you what is still in need of more venting.

    3.if replacing the boiler, you may want to read the excellent boilerpro article about undersizing the boiler, which only along with increased venting can reduce fuel consumption. i will try to find a link too it. get a meter on your makeup feed water so you know how much new water is being added.--nbc

    here it is:

    http://www.heatinghelp.com/article/11/Hot-Tech-Tips/1551/Taking-Another-Look-at-Steam-Boiler-Sizing-Methods-by-Dave-Boilerpro-Bunnell
  • Dave in QCA
    Dave in QCA Member Posts: 1,784
    Don't know what I was thinkin!

    Sorry, don't know why I thought you said 5 sections.  And, if it is an older model 88, it is not as efficient as the new ones, which have been completely redesigned, so my earlier post is pretty much worthless, except for comments on chlorides.

    Your present 988 boiler is about twice the size as you need.  If it is not leaking at the moment, you might look into having it downfired to match the load + 34% for piping and pickup.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • NickM
    NickM Member Posts: 25
    Dazed and confused

    OK from what I have read, the boiler is too big and this is resulting in the excessive burning of fuel oil.... correct ?

    Here is today's million dollar question,  can I remove sections from the 9 and get a more efficient boiler ?

    And what is down firing ? what do I tell my boiler Pros to do ?

    I have attached a photo of my monster.

    Thanks for the help -- all of you guys are great, 

    GOD BLESS AMERICA
  • NickM
    NickM Member Posts: 25
    Is this what I tell my PRO

    I read you responce, thanks for taking the time to help,  but is that exactly what I should tell my boiler Pro to do and he will understand , or is it above his head also ?

    I put a water meter on it several years ago and monitor it all the time We add very little water, ( after I fixed all the condensate lines)

    Thanks
  • NickM
    NickM Member Posts: 25
    DOWN FIRED

    What and how do I Downfire the boiler ?

    Thanks for the help
  • Gordo
    Gordo Member Posts: 852
    edited January 2011
    A Good Oil Burner Man

    Should be able to change the nozzles (there are 3 in that burner) to down-fire that boiler.  That should be done with the proper nozzles and with combustion test equipment and not "by eye". 



    That burner also looks capable firing low-high-low.



    Set it up to run at high fire until 4-8 oz/in2 or so with a vaporstat, then have it drop to low fire for the rest of the burn/heat cycle.  One psi should be too much.



    The above assumes that the system is properly vented, and by that I mean a mess of Gorton #2s and not just a lonely Hoffman 4a "quick-vent" somewhere at the end.



    Don't cheap out on the venting.



    I'd hire a good steam man to go over your system.  It don't sound like you've found one yet. 



    I'd insulate that header and any bare steam pipe.



    Good Luck!
    All Steamed Up, Inc.
    "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.
    https://heatinghelp.com/find-a-contractor/detail/all-steamed-up-inc
  • BobC
    BobC Member Posts: 5,470
    Reduce nozzle size

    I'm not a pro but my understanding is down firing  (reducing the nozzle size) by more than 25% is not productive. The burner has to be adjusted to run correctly at the reduced rate.



    My small boiler (a Burnham V75) has been down fired by 30% and I'm beginning to think I may have to go back up a bit.



    good luck,



    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
  • Rod
    Rod Posts: 2,067
    Boiler Problems

    Hi Nick-  One of the first things that would concern me when I read your post is the comments by your "pros". One says too big and the other one says too small. I'm just a homeowner and not a pro but I'm quite confident I can figure out the proper size of a boiler to match a existing steam system. Since one or more obviously don't know what they are talking about I'd go very slow on making any big changes like removing sections or down firing at least until I understood the whole problem. Earlier I asked where you are located as someone here maybe able to recommend a good steam pro to you. You might also look at the top of this page in the "Find a Contractor" section. Scroll down past the zip code section to your State and see if a pro is located near you. There are some very good steam pros listed there and since your "pros" are giving you conflicting advice, I'd seek a third opinion. You might also call Weil McLain and contact the factory rep. for your area as he might be able to put you on to someone with more steam experience especially in your size boiler.



    You haven't told us much more about your system. Is it a one pipe or two pipe system?

    Are just a few units overheating or are there a lot?   Your steam system should be running at 2 PSI or under. The Empire State building  http://en.wikipedia.org/wiki/Empire_State_Building (scroll down to the Architecture section for steam specs)

     runs at 2 PSI or under, so your system running at 5 PSI is too much. This can cause over heating and can also wreck your vents.

    I would also think that a boiler that size would be able to be configured with a multi stage burner so I would investigate that. Weil McLain should be able to give you advice on burners and what configurations are feasible.

    - Rod
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,314
    Nick I hate to say this but

    If you need to be here your boiler guy is not a pro. On the top of the page is a find a pro function. There must be a steam guy who does not need his hand held near you.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
  • jpf321
    jpf321 Member Posts: 1,568
    NBC .. typo?

    0-15oz??? do you mean lbs? and perhaps even 0-5lbs?
    1-pipe Homeowner - Queens, NYC

    NEW: SlantFin Intrepid TR-30 + Tankless + Riello 40-F5 @ 0.85gph | OLD: Fitzgibbons 402 boiler + Beckett "SR" Oil Gun @ 1.75gph

    installed: 0-20oz/si gauge | vaporstat | hour-meter | gortons on all rads | 1pc G#2 + 1pc G#1 on each of 2 mains

    Connected EDR load: 371 sf venting load: 2.95cfm vent capacity: 4.62cfm
    my NEW system pics | my OLD system pics
  • NickM
    NickM Member Posts: 25
    Finding the Pro

    The building is located in Mount Vernon NY (not exactly a nesting spot for the rich and famous)

    The system is two pipe and the water is treated every year

    Typical radiator is a single tube  -- pictured below  and all of them get very hot

    I have wasted lots of time and money trying to find a "Pro".  I am almost positive that if I use the words "downfire" to 3 out of 5 that they will start babbling and spew nonsense.    I will call  those listed on  FIND A CONTRACTOR  (3)  - but the descriptions indicate that they are geared to residential..... 

    If anyone has a contact  or company with experience in this I would surely give them a call.

    AGAIN - Thank you all for extending me your time and knowledge 
  • NickM
    NickM Member Posts: 25
    Insulating

    How do I insulate the Header --

    Is there a method or product you can recommend ?

    Thanks again
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,314
    I spent last January in White plains

    just north of you. It was a bit smaller of a building as it only had a 680 weil installed when it called for a 480. Did they only use one riser off that boiler?
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
This discussion has been closed.