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Higher Efficiency Pumps & Motors?

Tremolux Member Posts: 28
After wandering through the wilderness of "renewable energy", we've reluctantly concluded that there isn't any way , in our particular circumstances, to do it on a cost effective basis. ( Too much shade for solar, not enough wind, etc. etc. )

So, we're back to square-one with the original heating system: hot water & radiators.

Most of the radiators are cracked and need replacement, but the pipes are holding pressure. The old gas boiler ( Hydro Therm ) is at least 25 years old, probably more.

( We'll ask about high-E boilers & replacement radiators in a later post, after further online research. )

Right now, we're looking for little tweaks that could improve overall efficiency.

The electrical pump and motor that circulates the hot water must be a technology as old, if not older, than the boiler itself. Have there been any significant improvements?

If more efficient and/or more durable combinations are available, are they supplied by the boiler manufacturers, or are they a 3rd party option? Any suggestions would be appreciated.


  • Tremolux
    Tremolux Member Posts: 28
    edited August 2010
    Will this one work?

    Since there was *zero* response to our question, we did some online research and found a possible solution: grundfos pumps.

    This "Alpha" model appears to fit on a residential boiler.



    How do we determine what capacity range / flow rate to use?

    Or is that necessary since the Alpha pump adjusts automatically?

  • Slimpickins
    Slimpickins Member Posts: 327
    re: Will this one work?

  • hot_rod
    hot_rod Member Posts: 18,279
    grab the pump curves

    from that B&G and the Alpha to see how they match up. Assuming the B&G was sized to the application, heating OK?

    I have had several of the Alpha's running in my shop, both the first and second version. They perform as promised and reduced energy consumption at least 50%. confirmed with a "Kill o Watt" meter.

    I also have had one on my solar drainback system, seeing some fairly high operating temperatures, no problem.

    Wilo also has some delta p circs worth looking into. B&G offers ECM pumps also. I think B&G will approach this with ECM without the delta T or P function for a lower cost option.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Higher Efficiency Pumps & Motors

    Can you let me know the model number of the B & G?  Even a number of the casting and motor Hp would help.  Then I can do a cross reference to either a WILO ECO or Stratos, both will offer at least 50% electrical energy savings (as well as lower fuel consumption and lower system noise).  I can get pretty close to the flow if you can send me the boiler output too.

    You can E Mail me directly at [email protected] with this information as well as any additional information you might require.
  • Tremolux
    Tremolux Member Posts: 28
    edited September 2010
    Boiler & Pump Specs - etc.

    The pump motor says: "Bell & Gossett Booster" - Series 100 - A98.

    Below, in a separate box, it says "18" and next to that "225" with a "degree" circle.

    It also says: 1/12 H.P. - 1725 RPM - 1 PH - 60 CY.

    The pump itself has a casting mark that seems to say "P00351". ( Hard to read )

    The boiler is a Hydro Therm Model R210B "Low Pressure Boiler". Serial # RJ1333

    Input 210K BTU/hr - DOE Heating Capacity 164K BTU/hr -

    Net IBR Rating 142,600 BTU/hr

    One calculation, done by a "green consultant" with a blower door and room dimensions, said the heating load was 150K BTU/hr and that the boiler was undersized. We haven't a clue how well the old boiler heated the house, but it appears to have been very inefficient. It's a quirky, 2 story brick house, with three separate units, 3500 sq. ft. brick. The two upstairs units were used as rentals. The previous owner was a recluse with "mental issues" who allowed the water and gas to be turned off for two years while he continued to live there alone. The last records available from the gas utility showed four months, November to February, started over $400 and topped off at $670 per month!

    ( Another calculation will be done by an actual HVAC contractor, but they will base it on the number of windows and the outside dimensions. )

    The interior of the attic has been coated with foam, and many air leaks filled, but low-E storm windows haven't been fitted yet.
  • Higher Efficiency Pumps & Motors

    The Series 100 has a rather flat curve but based on the size of your boiler and description I guessing you would need about about 10 to 12 USGPM.  The Hydrotherm is a low friction loss Cast Iron type so the head required for the circ to produce would be about 8 to 10 feet.

    Our ECM solution is a WILO ECO 16 FX and is a direct bolt in replacement.  This is assuming you have a zoned system and are not a mono-flow T type.

    What it will do for you is slow the flow (BTU train) down at low load conditions, drastically reducing boiler cycling while providing a more efficient delta T (allowing the btu's to "get on the train" at the boiler and "off the train" at the heat emitters).

    If you give me your location I can direct you to a local wholesaler (these are now stocked all over the USA).

    I have attached information for you to review...
  • CC.Rob
    CC.Rob Member Posts: 128

    Household energy starts with conservation, then efficiency. If you've looked at renewables, and are now considering heating system, that implies that you have already done all the totally unsexy but utterly critical improvements to the building envelope.

    A useful way to think about this is the efficiency pyramid:


    Start at the bottom and work your way up. It's a useful and practical model. I do take some exception to the text of the article, however. In many places renewables are heavily subsidized which makes their economics a lot better and thus would move them down the pyramid. But as a general guide this is a great place to start. Note that heating systems come after a lot of other conservation and efficiency work.
  • Heat Loads

    150,000 btu/hr load sounds really high,  especially with a foamed attic.  To get an idea of the absolute maximum size of the boiler, measure the installed radiation.  The boiler does not need to be any bigger than what the radiators can put out plus some for the piping that heats the basement usually.  Also, if you have the fuel usage and average outdoor temps for the house, you can work backwards from them to see what the actual usage was for the existing boiler at a given outdoor temperature.  If the natural gas costs there are similiar to here, I would estimate the heat load to be about 100,000 btu/hr.   With the upgrades it sounds like you are making, that load will continue to drop.  My 105 year old 3,000 sq ft frame, with 800 sq ft of glass, (most of its original windows weatherstripped with storms) only has a load of about 50,000 btu/hr.  With caulked and tightened up windows and foam sealing the attic, you probably have a very tight home.  I would check and see if the home is really brick.   There are alot of homes built in the 30's that are actually wood frame with a full brick veneer.  The frame allows you to fully insulate the exterior walls.
    The Steam Whisperer (Formerly Boilerpro)

    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • Tremolux
    Tremolux Member Posts: 28
    Onward & Upward - Thanks!

    Thanks to everyone who provided feedback and guidance.

    We'll be double-checking the heat load, & probably do the "blower door" one more time, try a DIY calculator, and consult with local HVAC contractors before sizing the boiler. ( Might also calculate the heat output of the existing radiators, if only for comparison. )

    The reason for the high heat load is probably the windows. Though most are tight, there are a lot of them ... 34 double hung, 10 casement w/leaded glass, and 7 doors with 8 - 12 glass panes in each. If that weren't enough, there are 15 basement windows!

    ( The stone foundation rises 45 in. above grade. Basement headroom: is 6 1/2 ft. )

    We plan to install low-E storms over the windows, and have installed 3 storm doors. Other energy saving measures include a High-E ( non catalytic ) wood burning insert for the 1st floor fireplace, and 6 High-E ceiling fans to circulate the air.

    More questions will surely follow, as we examine options, and make decisions.

    Have a Great Holiday Weekend!
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