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Steam System Renovations and Savings

Dan Foley
Dan Foley Member Posts: 1,258
I will start a new thread rather than tack onto a previous thread that went astray.

We have worked on the steam and DHW system in a 47 unit apartment building in DC. It was built in 1901. It is heated by a one-pipe steam heating system. When we first got involved seven or eight years ago, their annual gas bill was $78k annually for heat, DHW and cooking.

We have since made the following changes in this order:

1. Added/repaired and balanced main venting system.
2. Replaced all radiator vents (done by maintenance staff, not us)
2. Replaced clogged wet returns.
3. Flushed out approximately 20 loop seals. Several were completely clogged with rust and sediment. These risers had no heat at all.
4. Replaced the existing 40+ year old boiler with a W-M LGB, approx. 2.5M BTU/hr.
5. Replaced broken Heat-Timer with tekmar 279 control with indoor feedback.

The above work was done over a three-year period. I anticipated that the six-figure sum for the above work would be offset by fuel savings over a ten-year period. Instead, the work paid for itself in four years. In 2013 the annual gas bill was $38k. The fuel savings do not take into account the even heat and tenant comfort provided by the upgrades and repairs.

The annual gas bill includes DHW which was provided by a 380k BTU tank-style water heater connected to a 500 gal. storage tank. In addition to the inefficiency of this set-up, the tank would fail every two to three years and replaced at a significant cost. This past summer we replaced the DHW system with two 500k BTU condensing boilers and four 120 gal. SS storage tanks. I expect to see the annual fuel savings to drop accordingly.

All fuel savings were documented by Jim Wood, chairman of the building and grounds committee at The Mendota Apartment building.

The following are editorial features on the project for additional reading if so inclined:

http://www.foleymechanical.com/wp-content/uploads/2016/10/Foley_Mendota_Plumbing_Perspective.pdf

http://www.foleymechanical.com/wp-content/uploads/2016/10/Foley_Mendota_Mechanical_Hub.pdf

http://www.foleymechanical.com/wp-content/uploads/2014/12/phc11_2014.pdf

http://www.foleymechanical.com/wp-content/uploads/2016/05/phc_5_2016.pdf


In my opinion, it is typically easier, with greater savings, fixing, repairing and upgrading an existing steam system rather than converting it to hot water. I also understand there are many ways to do a job and respect the opinions of those who would have done it differently. I know what works for me and my company.


- DF
IronmanNew England SteamWorksErin Holohan HaskellTurbo Dave

Comments

  • Canucker
    Canucker Member Posts: 722
    @Dan Foley Do you have data regarding any 2 pipe steam systems you have done similar work to? Could you compare the % difference it would have taken to switch those to a hw system compared to just repairing the existing?
    You can have it good, fast or cheap. Pick two
  • vaporvac
    vaporvac Member Posts: 1,520
    @Dan Foley , I know you didn't want to hijack the other thread, but it might be useful for the OP to have a link to your numbers.

    I'm not the least bit surprised with your results. My upgrades ie.new twinned boilers and pipe insulation added in unheated garage, have reduced my monthly bills significantly ie at least 30%, but nearer to 50% sometimes. This is with the temp set higher than before and without major resets. However, it doesn't even begin to take into account the amazing added comfort and silence. Before my only choice was to lower the Tstat if I wanted savings and why not. I was uncomfortable whatever the setting.
    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,453
    Nice job. Looks like a home run to me. Can't beat half the fuel savings!! The original boilers are really old, brick set, and appear to be brick supported but don't appear to be hung from steel beams as was usually the case
  • Steamhead
    Steamhead Member Posts: 16,796
    Nice job!
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Abracadabra
    Abracadabra Member Posts: 1,948
    "The boiler was sized to the connected radiation using a 1.5 pick-up factor."

    ??

    Why 1.5? Uninsulated mains?
  • Dan Foley
    Dan Foley Member Posts: 1,258
    edited October 2016
    @Canucker I have renovated many 2-pipe systems, both commercial and residential, but I do not have hard data on savings.

    @EBEBRATT-Ed The original coal-fired boiler is still in place and set on brick (no steel beams). The building was built around it.

    @Steamhead Thanks, Frank

    @Abracadabra The boiler was sized using the method outlined by The Master in Lost Art. The two 6" mains in the basement have been re-insulated with fiberglass. One loop is approximately 180' long. The other loop is approximately 300' long. The 20+ risers are not insulated and run seven stories up un-insulated masonry outside walls. There is a significant pick-up factor in this system.
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,513
    Dan, this one has been a great story from the start. Thanks so much for including all of us in the adventure!
    Retired and loving it.
    Solid_Fuel_Man
  • Canucker
    Canucker Member Posts: 722
    Too bad @Dan Foley . It would be interesting to hear from someone who had eyes on the old system as to what it would have taken to complete a conversion and the possible added cost to complete it properly, even as a hypothetical exercise.
    You can have it good, fast or cheap. Pick two
  • Canucker
    Canucker Member Posts: 722

    Canucker said:

    Too bad @Dan Foley . It would be interesting to hear from someone who had eyes on the old system as to what it would have taken to complete a conversion and the possible added cost to complete it properly, even as a hypothetical exercise.

    Since it is a one pipe system, there really isn't much of a discussion as to whether the added cost is worthwhile. Without the piping, it would never make any sense.

    In fact, drawing a conclusion that rebuilding an existing one pipe steam system is more efficient and less costly than a HW conversion really cannot be substantiated as I don't believe anyone would attempt such a conversion in the first place.
    Agreed. That's why I inquired about any 2 pipe systems he had rescued in an earlier post
    You can have it good, fast or cheap. Pick two
  • Steamhead
    Steamhead Member Posts: 16,796
    Canucker said:

    Too bad @Dan Foley . It would be interesting to hear from someone who had eyes on the old system as to what it would have taken to complete a conversion and the possible added cost to complete it properly, even as a hypothetical exercise.

    I think he's already covered that:
    Dan Foley said:

    ......... The 20+ risers are not insulated and run seven stories up un-insulated masonry outside walls.

    Not insulated and on outside walls- sounds like they could freeze in cold enough weather if someone filled them with water. This tends to attract lawyers.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • BobC
    BobC Member Posts: 5,476
    And we all know how expensive lawyer repellent is.

    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
  • Mad Dog_2
    Mad Dog_2 Member Posts: 6,831
    Way to Go Foley! Mad Dog
  • Steam
    Steam Member Posts: 45
    Awesome job! Really outstanding savings on the project.

    Love the coal boilers. They are brick set HRT boilers. The one on the left has stationary grates (probably original setup for both). The boiler on the right looks to have been modified at some point. No upper fire doors, only lower doors. What is under the steel plate? Underfeed stoker?

    You can't tell if the boiler was supported by steel beams by looking at the front of the boilers. You have to look at the sides. There would be two steel I beams along each side of the boiler, and they would be secured to another beam that would go over the top of the boiler, where tension rods would extend down and attach to the lugs. Hrt boilers below 54" in many cases had to be supported by the same outside suspension setting with no less then two steel supports on each side per boiler rules. That is not to say boilers werent constructed in weird ways, even ppl using wood beams to support the boiler :00

    The walls of a strictly brick boiler were prone to crack and suffer air leakage and loose efficiency. To try and remedy this, they used double wall construction, with asbestos blanket in that airspace, which helped relieve alot of the expansion and contraction and helped, but the best construction was the outside suspension setting.

    Even the hrt's with overhang fronts used the outside suspension boiler setting, supported at 4 points.

    When you open the fire door, you should see the dead plate at the front before the stationary grates, and looking back the bridge wall. Throwing green coal on the deadplate would help deive off volatile's resulting in reduced smoke (when burning bituminous). Don't throw coal passed the bridge wall!