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What to buy. (replacement circulators)

JOSYS36
JOSYS36 Member Posts: 50
in Radiant Heating
Well it's getting to be that heating time of year and I'm up to my arm pits trying to figure out which circulators I should install to replace these existing power pigs.



I want to be able to run the circulators all the time and I'll have an outside air reset installed to modulate the water temperature. I'll tell you for the average joe, not a dumb one, but just the average joe figuring this sizing thing out for me has been a challenge. Maybe I am over thinking things can you guys can help me make this simple.



1. I just want to replace these two B&G 1/6 horsepower models with something that will still run at set speeds, but will use less power. Again, I want to use these circulators running all the time.



2. The pipes that serve the circulators are 1 1/4 and are connected to larger cast iron. This is a gravity conversion of a system that was put in about 1905. I see from Dan's books that you can run about 14 GPM through 1 1/4 pipe. Right now there are two zones and the stats only shut down the circulators. Later I will be changing that.



I have looked at various pumps like the Taco bumblebee and the Alpha, but I can't seem to figure out which is going to work best. Any help you can provide would be MOST welcome! I've been at this for a day and I need to move on.



Jason
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Comments

  • SWEI
    SWEI Member Posts: 7,356
    More info

    How many GPM do you actually need to move in order to heat the space?  What is your design day heat loss?



    Are there any zone valves or radiator valves in use (things which would change the amount of flow based on temperature or user input)?
  • JOSYS36
    JOSYS36 Member Posts: 50
    No valves

    Right now there are no valves closed, and there are no zone valves. Basically the system is wide open.



    The two pumps that are working the system currently are doing great. I just don't like the temp changes, and running those pumps all the time is going to suck electrons.



    Jason
  • SWEI
    SWEI Member Posts: 7,356
    edited October 2013
    No valves

    OK, not a problem



    Still need to determine how many BTUs you need to move into the house on a design day.



    Can you post some photos of the boiler, pumps and nearby piping from different angles?



    How are you planning on adding outdoor reset?  Is there a new boiler involved?



    Edit: re-read your original post and see that these are indeed zone pumps.  Are they B&G PR's, NFI's, or something else?
  • JOSYS36
    JOSYS36 Member Posts: 50
    Took some pics.

    Attached are some pics.



    Basically the house is cut up into two main zones. The north half of the house and the south half of the house. The house is just about a perfect cube with 4 rooms on the first floor, and then 4 rooms on the second floor. The basement is also the same floor plan and surprising for 1860 was fully finished. The current boiler room was actually the original kitchen.



    Even more interesting is that I know who installed the original system. His name was Burt Poffenbarger and he installed heating systems of hot water, steam, and air all around this area.



    Jason
  • Zman
    Zman Member Posts: 7,610
    Lost art..

    I would start out by reading this http://www.heatinghelp.com/article/343/Circulators/238/Sizing-Circulators-for-Hot-Water-Heating-Systems



    If you measure the EDR as he suggests you can determine the proper circulator for your system. Once you determine that, compare the curve of that circ to some of the new ECM models.

    You are better off doing outdoor reset with a new boiler controller. The only other way is to repipe.



    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • JOSYS36
    JOSYS36 Member Posts: 50
    OK I think I have some better ideas.

    OK I have more information now! Tomorrow I am going to do some calculations in the EDR and post back.



    Thanks!



    Jason
  • SWEI
    SWEI Member Posts: 7,356
    She's a beauty!

    How will ODR be implemented?  Are you keeping the original boiler?  It appears well preserved, but has it been inspected and tested lately?  Beware of salesmen who are trained to push replacements for anything over 10 years of age, but there are genuine concerns at this age.
  • JOSYS36
    JOSYS36 Member Posts: 50
    IT IS!

    This particular Crane boiler was put in about 1950 or 51. I'm not sure of the date and neither is the original family. All she can remember at this point was that when they were preparing the house to move in (the grandson of the people who purchased this home in 1879) they replaced the coal fired boiler with this one. It had an oil burner when it was put in, but then they switched it to gas in 1975 or so. That burner has been looked just about every year and is working well. The local guy knows about the burner, but not much else about hydronic heat. Heck I now know more from reading book and my own system then he does. But, yes the boiler is fine. Right now I am not going to replace it. What I will probably do is just control the water temp manually and increase it as our heating season gets worse. Really we don't need to be heating this house much until the December, January time frame. Then it can pretty much run at 160 degrees and keep the house warm. I had problems with my expansion tank last year so we never did set the temp to 180.



    Jason
  • SWEI
    SWEI Member Posts: 7,356
    ODR

    Heat loss calc will determine worst case flow required to heat the house.  Radiation survey will determine the maximum water temp needed.  From those all else will follow.



    You might want to consider a Taco iSeries-R mixing valve http://flopro.taco-hvac.com/products/index.html?category=188
  • JOSYS36
    JOSYS36 Member Posts: 50
    edited October 2013
    Caled BTUs and EDR

    I did the calculations for EDR and came up with a number of 579, and the BTUs were 98,388. I've attached my sheet so someone can see if these numbers look correct.



    Thanks!



    Jason
  • SWEI
    SWEI Member Posts: 7,356
    edited October 2013
    A radiation survey

    is one part of this.  That tells you how many BTUs the radiators can put out.



    The design day heat loss is the other part.  It tells you how many BTUs you need on the coldest day in a typical year.
  • JOSYS36
    JOSYS36 Member Posts: 50
    I'll get to work

    OK I'll get to work on that and post back what I find.



    Thanks!



    Jason
  • SWEI
    SWEI Member Posts: 7,356
    Heat loss calculation

    http://www.slantfin.com/index.php/homeowners/ipadapp will help.  There are plenty of other options online as well.
  • JOSYS36
    JOSYS36 Member Posts: 50
    I'll get to work

    I put that app on my phone and working on it right now.



    J
  • JOSYS36
    JOSYS36 Member Posts: 50
    New Numbers

    I came up with 40,642 for the first floor, and 39,008 for the second floor. The first floor is larger with the bathroom and kitchen area attached to the back of the house. The second floor is 4 cookie cut bedrooms. Basically the first floor minus the bathroom and kitchen is 4 cookie cut rooms. 2 Living rooms, my office, and then a dining room.



    The total I came up with is 79,650.



    J
  • SWEI
    SWEI Member Posts: 7,356
    Numbers

    Just to sanity check this, how many square feet is the house and what is your outdoor design temp?  Have there been any insulation or window upgrades since the house was built?



    79,650 BTUs divided by 579 square feet of radiation gives us 138 BTUs per square foot.  Assuming the radiators are properly sized for each room (highly likely given the age and quality of the system) and that your heat loss is correct, you should be able to heat the place comfortably using 165ºF water on a design day (using cooler water the other 98% of the time.)    



    At a 30ºF ∆T you will need 5.3 GPM (8 GPM at a 20ºF ∆T) which can easily be handled by a single Tack Bumble Bee HEC-2 circulator.  Be sure to flush and clean the system with a good hydronic cleaner (Rhomar, Fernox, etc.) before you remove the old circulators, and add a magnetic dirt separator (Caleffi DirtMag or similar) before you install the new one.



    A 4-way Taco iSeries-R should handle this with aplomb.  Set the thermostat to 80F or higher and then adjust the reset curve over the course of a few weeks until everything is comfortable.  Then move the thermostat to about 2-3F over the desired internal temp and leave it there.  If properly located, it will prevent overheating on a sunny day or if you fire up the woodstove.
  • JOSYS36
    JOSYS36 Member Posts: 50
    Numbers

    The house is a bit over 3000 square feet. It actually looks much higher due to the basement having full 8 foot windows with 4 feet exposed.



    There has been upgrades. The windows had new storms added, and there has been insulation added to the full attic space. Nothing was done to the walls since they are 15 inches of brick with a thick layer of plaster added. In fact due to the exterior and interior walls being brick all the radiator pipes are exposed on the first floor. This is fine by me as all that heat just goes into the room.



    SWEI you have been LOTS of help and I have learned a lot doing this! If there was another circ for this type of job (remember I will be replacing two) is there any others you would recommend?



    If anyone else wants to chime in please feel free.



    Jason
  • Gordy
    Gordy Member Posts: 9,546
    Dining room rad

    Is a sweet one do you warm the dinner plates with it?
  • JOSYS36
    JOSYS36 Member Posts: 50
    Not much.

    Actually not much, but yes you sure could. Back when the system was gravity fed it would stay warm all the time. Then you could put your dinner rolls in there and they would stay warm. With the system like it is it cycles on and off, so the rad will cool down and then warm up. Not the best setup if you want to actually use the warming functions.



    Jason
  • Ironman
    Ironman Member Posts: 7,510
    Nice rads

    Especially the two-tone paint job.



    A couple of considerations:

    First, realize that there is a difference between the Alpha and the BumbleBee. The Alpha is a delta P circ and the Bumblebee is a delta T. The Alpha is looking to calculate and maintain a certain pressure differential (delta P) when set to the "auto adapt" mode. The BumbleBee must be set by the installer to maintain the desired temp differential (delta T). It also has two sensors that go on the supply and return respectively. Either will probably work fine, but a little more is involved with the BumbleBee.

    Second, outdoor reset may not benefit you much with your present boiler. You don't want to go below 130* on your return temp or else you'll have flue gas condensation and the horrors that accompany it. Also, with a converted gravity flow system, the high mass of the large pipe volume and the c.i. rads produce a sort of natural reset that mimics outdoor reset. Thus, adding outdoor reset seldom benefits this kind of system when you have a c.i. boiler. A mod/con is a different issue as it's designed to have cold return water.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • JOSYS36
    JOSYS36 Member Posts: 50
    Got ya.

    What I was going to do at this point is install the Bumblebee and just run it at it's fixed speeds until sometime down the line I could replace the boiler. It will happen sometime but not yet. There are too many things that have to be done and I can't put that one on the list at this moment. My main thought was to run the circulators all the time to help with the room temp changes, and help with the moving electron consumption.



    I'm really not married to either option. So if I was not going to replace this boiler for the next couple of years maybe it would be better to just install something simple.



    J
  • JOSYS36
    JOSYS36 Member Posts: 50
    Thinking again.

    OK so if I am thinking this through, if I went with the Bumblebee I could then modulate the Delta T. In other words when I don't need as much heat I could set the delta T to be something like 10 degrees, and then when I need more heat I could then set it to something like 20. I assume the pump runs faster with a lower delta T then higher. Makes sense if you fly water through that boiler it should not be able to pickup or release as much heat. Then I could start the boiler temps out at like 140, and as my needs went up I could increase that to something like 160. I've never ran the system past 160 and things were fine last year. It actually ran much better when it got down to 0 and the circulators didn't shut down. Then if one zone did heat up too much I could always just shut it down depending on the day we are having. The weather here can flux quite a bit this time of year. We can have a 40 degree day one day and a 80 degree day the next. So being able to shut the circs down would then ensure that all that hot water just stays in the boiler. When this does occur the boiler runs very infrequently.



    J
  • Ironman
    Ironman Member Posts: 7,510
    Not Exactly

    The delta T is set at fixed point on the BumbleBee and left there. You don't keep shifting it. That's the whole point of delta T. By maintaining a fixed delta T, the pump will automatically change speed as the load varies and more or less heat is extracted.



    It does not have a constant circulation function as that would defeat the purpose of a constant delta T. If you ran it constantly, the delta T would quickly drop to 0* once the boiler shut off and the circ would slow down to its minimum.



    If you want constant circulation, then you need to go with the Alpha which is a delta P and feed power to it constantly. However, I don't think constant circulation will benefit you that much.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • JOSYS36
    JOSYS36 Member Posts: 50
    Manual

    I did download the manual for the Bumblebee and it had 3 modes.



    CP - Constant Power (Fixed Speed)

    Allows for 4 fixed circulator speeds



    SP - Setpoint (Variable Speed)

    Allows for a fixed supply temperature from 65°F to 220°F.



    dE - Delta-T, Differential Temperature (Variable Speed)

    Allows for a fixed system temperature differential (∆T) from 5°F to 50°F.
  • Ironman
    Ironman Member Posts: 7,510
    Constant Power...

    Is a fixed speed. No delta T when this is chosen as that would not be possible with a fixed speed.

    The Alpha can vary its speed and give constant circulation when set to "AutoAdapt". This would be a better choice for what you're attempting, but I would recommend using the BumbleBee in delta T mode.

    Try it with it set to the standard 20* delta T and see how it does. Adjustments can be made to find the sweet spot. Then, leave it there.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • SWEI
    SWEI Member Posts: 7,356
    circulator replacement

    One HEC-2 will move enough water for both of the existing zones (some plumbing required.)



    Good point on the return temps.  Your system would really sing with a mod/con boiler.



    With new windows and insulation, I'm somewhat surprised your current heat loss comes that close to the installed radiation capacity.  Maybe they used to spec 200ºF supply water?
  • JOSYS36
    JOSYS36 Member Posts: 50
    I'll be posting.

    I'll be posting the results by early next week.



    Jason
  • JOSYS36
    JOSYS36 Member Posts: 50
    Found a local guy!

    Trying to find the system cleaning chemicals I was able to stumble across a local guy. He sure does not advertise very well, but him, his father, and his grandfather going back to about 1900 have all done nothing but steam and hot water heat. I put out a call to him yesterday and we should be able to talk today. I'm actually relieved that he is in his 60s. You just can't seem to find younger guys who know as much about this stuff. I'd love to follow this guy around for a few years and gleen as much as I can. There is also a chance that his father is who installed this updated system in the 50s.



    Jason
  • SWEI
    SWEI Member Posts: 7,356
    If it turns out you do have the right guy

    send him over here.  I suspect he may enjoy the place.
  • JOSYS36
    JOSYS36 Member Posts: 50
    I will

    I will ask him if he knows about this site or not.



    Jason
  • JOSYS36
    JOSYS36 Member Posts: 50
    Well so far.

    Well so far I have two circulators here and I am waiting for the guy to come and help me. I've had two people out here, but you can't seem to get anyone to call you back. I know it's the beginning of heating season so people are crazy busy, but you think you could at least return a phone call. In any event,



    I have two questions,



    When I measured these radiators I think I made a mistake. When I did their height I did not measure from the floor but from the bottom of each tube to the top. In doing more research it looks like you would measure from the floor which would add several inches. This would then increase the EDR of each radiator and add to the BTUs put out in each room. So do you measure from the floor?



    The second question I have is probably much more complex. I had originally thought that I would convert the system to continuous circulation and then just adjust the temperature as needed. I found out that would be a bad idea due to flue gas condensation. This is a CI boiler and right now I don't have plans to replace it. So then if that won't work would stop and start circulation with a much higher water temperature basically give me the same thing. Since the system is starting on a much higher water temp such as 180 or 185, i would assume that the radiators would add more heat and then I would have longer periods between heating cycles.



    I was smart this year and cut down about 22 trees around this house. Now I get a lot more sun and actually have saved quite a bit from just the solar gain alone.



    I've attached a pic of what I am actually heating.



    Jason
  • Ironman
    Ironman Member Posts: 7,510
    Two Answers

    1. You measure rads from the floor to the top.



    2. You don't want to use constant circulation and you definitely don't want to keep the boiler hot. The dead men designed that system to be as efficient as the technology of their day allowed. A more modern boiler and forced circulation have been added, but trying to redesign the system is not a good idea. You should pump at the lowest rate that provides heat to every rad. Let the boiler cycle as the system requires - the longer, the better. That means using the coolest water that will provide sufficient heat while protecting the boiler and venting system. That's about 130* return temp. Running the boiler hot all the time will only cause shorter cycles and greater energy consumption.



    If you ever installl a mod/con, then some of the rules change. But with what you have now, the smart circ's and setting the thermostat for the longest cycle rate are the only things that will benefit as far as controls go. Insulation and sealing the envelope of the house will give you the best ROI.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • JOSYS36
    JOSYS36 Member Posts: 50
    OK then.

    OK so then my measurements for each radiator were off. So then each radiator is capable of putting out more BTUs into each room. Probably not much more then I calculated so I'm not going to loose sleep over it.



    Now as far as number two does boiler cycle mean the time between runs, or the time the boiler itself is running? I'll have more questions based on this answer.



    Jason
  • JOSYS36
    JOSYS36 Member Posts: 50
    Also thinking.

    OK so if I am understanding this correctly the goal would then be to decrease the amount of times the boiler actually runs, not to reduce the time in which the boiler is actually running. That would really make sense. Who would care if it runs 10 to 15 minutes if it only ran every hour or so. Would that not be better than running it for 3 minutes every 20?



    Also I'm giving thought to replacing the two thermostats I currently have. One is a Lux and is programmable the other is a Honeywell and is programmable but quite frankly I never use the programming functions. I would just rather set one to 70 and the other to 65 and be done with it. Does Honeywell make a thermostat that is designed to just work with hot water heating? There is no air in this house so I could care less about that.



    Jason
  • Boiler wrestler
    Boiler wrestler Member Posts: 43
    Pumps

    Jason,

    Boiler cycle pertains to the on/off cycles of the burners.

    Are you planning on separating the house into two zones? or are you just referring to two loops on either side of the house. I ask because I only see one circulator in your photos and I see no reason one would not be fine in the future.



    BW
  • JOSYS36
    JOSYS36 Member Posts: 50
    Two Zones

    The house has two zones. North half and the south half. I keep the north side off until I really need it, and the south half I heat to about 70. I can close off doors and upstairs rads to keep more heat in where I want it.



    Jason
  • Boiler wrestler
    Boiler wrestler Member Posts: 43
    Run time

    Yes it is more efficient to run the burner for longer rather than short cycles. As for hydronic specific stats I am not aware of any, and programmable ones are not recommended.
  • Ironman
    Ironman Member Posts: 7,510
    Thermostats

    Tekmar 518 is designed specifically for radiant heat including radiant floors. Most of Honeywell digital stats, from the 3000 series and up, have adjustable cycle rates. Set it for one per hour.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Mike Kusiak_2
    Mike Kusiak_2 Member Posts: 604
    Present controls?

    How is the burner being controlled at the present time? Is it maintaining constant temperature under the control of an aquastat, or does the burner only come on when one of the zones calls for heat and the circulator runs?



    If you are maintaining constant 180F at the boiler and just controlling the circulators with the thermostat, it is certainly understandable why you are getting the extreme swings in room temp.



    You would be much better off if the aquastat only maintained a minimum boiler temp of 130F and then had the burner only fire when either zone called for heat. That way you would have the benefit of the "natural reset" Ironman mentioned and much better control of room temp.
  • JOSYS36
    JOSYS36 Member Posts: 50
    I'll check

    I'll check that one out.



    Jason
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