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    Delta-P/Delta-T Part #4 (17 Posts)

  • Chris Chris @ 9:58 AM
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    Delta-P/Delta-T Part #4

    This is fun stuff!

    http://jbblog.flopro.taco-hvac.com/motor-of-emotion/
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • knotgrumpy knotgrumpy @ 11:53 AM
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    Not really fun...

    Chris, respectfully, I disagree.  This has not been a fun series at all.

    John has gone after this competitor's particular pump for about 4 posts now.  The first post was full of snark referencing some anonymous internet forum.  That was sad.  The snark has been dialed back some, but it is obvious he has picked a certain pump for a certain lesson Delta T doubters are to learn. 
     
    Taco is a great company.  There is just no need for this.  If you look around the forum today you will find a positively awesome feature on Taco done by Fox News.  Very uplifting.

    The Bumblebee is a great product - no need to try to lift it higher by casting the competition as inferior technology.  I think there are Delta P pumps that will adapt to the situation he has outlined, he probably knows that.

    He finished his blog last time asking how you would measure head loss in an established system?  Well, his company has a document to tell you how to do exactly that.  I used the instructions with good results.  It is here:

    http://www.taco-hvac.com/uploads/FileLibrary/PumpCurves.pdf

    If you follow the instructions you will be able to nail the head loss pretty closely. 

    I get that you are a fan, and I have learned a lot from John as well.  I just think something got set off a bit ago in a post about using the Bee in a TRV situation.   It just should have been hammered out here, not by taking anonymous shots across blogs.  Not good practice for a great company in the age of Google caching snarky comments for eternity. 
     
    This series has just made me sad.  Not more or less inclined to use a Bee, but less inclined to ask open questions on this forum because I'll wonder if I'm the idiot John Barba is talking about.  I know I'm an idiot, I will just wonder if I'm THAT idiot.
  • Chris Chris @ 12:54 PM
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    Lighten Up

    I don't see any bashing in any of the blogs on this subject. He is simply
    showing how that pump operates and how the bee operates.

    He has given you the tools to make a decision. How you use them and
    the choice of product you use is up to you. Has he written anything not
    truthful? Use the math and the education he has given and put it to
    good use and pick the best product based of the application it needs to work
    in.

    In the end that is what the entire blog is about.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • knotgrumpy knotgrumpy @ 7:16 PM
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    Lighten up

    No need.  I don' think I'm hysterical or anything like that.

    I was making a comment on a company's on-line demeanor.  I am a business man.  I run an on-line company and I would never let anyone in my employ use a competitor as a straw man to whack at in an attempt to boost my own product or company in a web posting.  I do not see that as a positive business model.  We are either a good company, or we are not.

    You want to attack a CONCEPT, go for it.  You want to unfairly compare your dissimilar product to their's for 4 blog posts running, not winsome.

    As to the substance, I didn't like this tease from last week:

    "There’s one  big elephant in the room, however.  When it comes to
    Delta-P  programming, how the heck do you determine the system head
    loss, especially in a retrofit?



    Great question – one we’ll address next time."

    Well, he really didn't address it so well in the next posting, but he says he will next week. Until then...

    When someone implies there is an "elephant in the room", it sounds so juicy, doesn't it?  Here's a problem that no one talks about - determining pesky head loss!

    Like I mentioned, Taco's own website shows you an empirical method for measuring head loss.  A homeowner can do it, elephant sitting in the room or not.  Couple of fittings, ball valves and a single pressure gauge.  I've done it.

    If you are a pro you can install a few inexpensive Pete's Plugs and measure the pressure differential before and after the pump while opening and closing zone access.  Head loss is a knowable number not a nebulous hypothesis.

    I guess I'm just saying directly to John if he reads this - I love your fire.  I love the music.  I love the way you love Taco.  I didn't like the starting tone of this series and I think a few on here have voiced similar concerns after the first posting.  Please teach and don't taunt.  Don't tease.  Don't denigrate.  Take the high ground.

    You are now free To Be Cruel to Be Kind to me :-)



     
  • SWEI SWEI @ 12:19 PM
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    Research time

    I will have an opportunity to compare strategies next heating season.  We have two Stratos pumps serving over 100 radiators and a handful of fan coils in a hotel.  They ran on ∆P-C last season, but we have wells which will get temperature sensors and controls this summer so that they (and the associated 100+ proportional motorized valves) can be run ∆T, ∆P, or some yet-to-be-written hybrid algorithm) next winter.
  • heatpro02920 heatpro02920 @ 7:59 PM
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    I think they both have their place

    in a hydronic system, in my own home system I use an alpha for my primary loop and a bumble bee on each zone on the secondary...

    I also like to use alphas on systems with zone valves, mixed radiant, and they work good with trv systems too... To be honest the only time I use delta t is for a pump on zones that never are going to change head pressures. Like a hydro air, baseboard loop or unmixed radiant loop ect... So in other words if the system has a set head pressure I use delta t, if it has a head psi that is going to change, such as multiple zone valves, radiant with a mixing valve, primary loops, ect I use delta P.

    I also like the bumble bees but the alpha feels like it is made better, I also like the fact that you can move the digital display to match the install... Plus its cheaper
  • knotgrumpy knotgrumpy @ 8:27 PM
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    Alpha on primary

    Hi Heatpro,

    What mode do you run the Alpha on in that situation?

    Thanks,

    Mark
  • heatpro02920 heatpro02920 @ 9:56 PM
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    I haven't had much time

    to play with it but I did a pair of Triangle tube solo 60s and I believe we ended up setting it on auto adapt, in my house I have a tt solo 175 with an alpha {originally installed a 0011 per the tech supports recommendations, that was a mistake} I have the alpha set on high constant pressure, I tried it a few different ways, but didn't have much time with it since it was the end of the heating season, and now its 78 during the day sooo.....

    But in my own home, I noticed when the unit started up, and the alpha ran, and one bumble bee called in {the bee will run on high for a bit}, the alpha would ramp down a tiny bit with the bee, then if another zone kicked in, the alpha would adapt to pump a little more and then not ramp down when the bee ramped down, but on the third zone it would ramp up when it called in and stay full high even when the bee ramped down to meet the delta...

    I am happy with how that works, but I think it will work just as good set to fixed speed to meet your need for a primary secondary since the pressure is just cycling through the heat exchanger and back to the unit...
    Now on a system like I installed yesterday and today, I had 6 zone valves and 1 alpha, I use the newer taco zone valves {I like them a lot too}, I run the pump on auto adapt and it works great, if one zone calls it pumps a base line, then when another opens it pumps more, and then another, and so on.... With delta tee as a zone valve pump, when 1 zone is calling and the pump slows down to meet the delta t you set that is great, but when another zone opens, the cold return water comes back an the pump ramps way up feeding too much water to the zone that was already hot, I notice watching the temps, that with an alpha the already hot zones delta stays pretty constant, as does the zone that just opened after it gets rid of the cold return water that was in the zone... Seems like multiple zones on a bee isn't the greatest idea, although like I said on a single zone that doesn't change, they work awesome.. Plus the alpha pumps more water, I know the bee tops out at 15 ft of head and 15gpm but I think the alpha pumps up to 19ft of head and 23+ GPM {obvioulsy not 23gpm at 19ft, them are the curve numbers} but that is a good deal more than a bee, hence why I use them on tt primaries...

    obviously these are my opinions on what I have seen in my installs, sadly I don't get as much time to play these days or stick around and watch the results, but next heating season I am really going to play with the TT and the alpha/bee setup in my house, It doesn't run much since I use heatpumps down to 47-50 degrees and on real cold weekends I run the coal furnace, but when it does it runs gooooood....
  • SWEI SWEI @ 10:20 PM
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    Have you considered trying a 'Bee on the primary?

    Boiler loops pretty much scream for ∆T pump control.
  • heatpro02920 heatpro02920 @ 7:31 AM
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    Swei,

    The bee would be a little underpowered for some units {when you ask the TT tech support, they want 15gpm through thte he all the time}...
    But I tried it on a Buderus gb 142 as a replacement, and the unit locked out rite in front of me, the pump started off ramped up to 100% the burner ramped up then the bee dropped down and the control locked out... I didn't have a ton of time to play with it so I set it on fixed high and it was fine...

    as long as you are using delta t pumps on your secondaries, then why do need one on your primary? Just set the pressure t so you get what ever flow you want no matter how many zones are calling, since the manuals mostly mention flow and not temp diff... I notice with the TT's and the GB's if you slow that flow down too much they are going to over heat and fast, even the time it takes for a circ to ramp up or down that HE will be over heating... With all circulator systems this isnt as much of an issue but for a system with zone valves, that little bit of time it takes for the valves to open and everything to get flowing and the boiler is shutting itself down under the wrong circumstances, like a cold boiler, all zones shut down, then the control kicks in the burner and primary circ, the zone valve starts to open the bee ramps up and then drops down and as soon as it drops down the boiler shuts down...

    I havent had a ton of time to play with it, but I like the delta p because this doesnt happen, now with the alpha on some systems if you set it to the full variable setting and the bottom of the curve doesnt at least match the minimum flow of the boiler, you will have problems, that is what I ran into with the tt 175 and alpha, I needed to set it at the high constant pressure setting because on auto with one zone calling the flow would go too low for some reason with a couple zones calling it would be fine... I noticed it acts different than you would think it would, when the secondary circs start to pull the alpha slows down, where in a non p/s system with zone valves when more zones call the pump ramps up.... But this all depends on what you set the settings at...
    Im still learning with this setup, since i just started using the TT's and the alphas as primaries...

    I would like to see a few more bees, like a stainless one with built in timer {the fixed temp setting would be nice for recirc systems}, one with a little more power maybe 25ft/25gpm,
    Also for recircs a ss delta pump that you can use to pump through rinnai units {since now they allow it} and automatically shuts itself down when the delta closes, faster than an aquastat...
  • SWEI SWEI @ 11:21 AM
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    ∆T on boiler loops

    because they have a fixed head and variable (in the case of a mod/con) heat output.

    What TT Prestige needs 15 GPM all the time?  250 wants 12 GPM @ high fire, 399 wants 19 GPM @ high fire.  The 'Bee curve is a little steep for a perfect match on those low HX losses, but I'd assume the ∆T control would have sufficient authority.
  • Chris Chris @ 1:02 PM
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    What's Interesting

    PT 175 Min Flow Rate at High Fire is 8gpm @ 1.5' of head. The bee would be set to fix speed 2 and would operate at just around 9gpm.

    154,000/500/8 = 38 Temp Rise

    Yet the tech wants him to size a boiler pump for a 20 Rise where the pressure drop across the HX is about 2' @ 15gpm. No over pumping there aye?
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Eastman Eastman @ 12:39 AM
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    I continue to wonder

    how each control strategy affects the frequency of unsynchronized zone calls.  I feel like unnecessary micro loading dwarfs the 5 watts or so typical difference between delta P and T minimums in a manifold based system.
  • Paul48 Paul48 @ 12:33 PM
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    Brings To Mind

    An old comedy routine.......A man looking up at the sky, and saying,"Doc it hurts when I do this", and the doctor replying,"Son, don't do that".
  • heatpro02920 heatpro02920 @ 8:32 PM
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    I need a little more time with the TT

    Boilers to decide which way to go, tech support drives me crazy, I got 3 different answers and then followed what they wanted which was a 0011 {which was insane....} so after that I am at the alpha and it works... I was at the supply house last week and a tech {I don't know him but seen him around} was buying a 175, and asked if the pump came with it, they said no and threw a 0011 on the table, I just shook my head, I wanted to say don't bother with that pump, but its not my place to ruin their sale... Even in the manual it shows, 0010 0011 0012 which all of which are too much, they list a 0010 on the solo 60, and you know some techs out there that want to be safe and not sorry go with the heaviest pumps listed, so you know there are a bunch of solo60's out there with 0010 primaries on them....

    Im not sure their reasoning, one tech supporter told me it keeps the exchanger clean and another told me its to make up for the installers bad designs, so who knows, This will be the first full winter with them ( I have installed 13 now not counting my own) and I have 9 more on the book for this summer so far, and Im doing 5 sales calls a day so by the end of summer hopefully we will be around 30 installed for this winter, then we will say if they stand up like the GB's did... The first year I used GB's I installed over 30 and didnt really hear from any of them, that was a good feeling, and then after the second year with basically NO service calls from the GB's I knew it was a decent product, I have them out there for a while now and they work... Thats why switching to the TT was a tough call, it was between the Vsman and the TTs and after looking them over I like the TT {plus easier for me to get, the 2 companies I do the bulk of my spending at do not sell the big V...} Time will tell if I made the correct decision. Already got over $100K of TT's out there and have only been selling them for a few months, it would be a disaster if they were junk, lol...


    Swei I just dont know about the bees power, on high it doesnt seem to really pump much, I never put a flow meter on it, and Im sure it flows the 15 they say, but just dont feel like it moves nearly as much water as the alpha, PLUS the bee is HARD to get rite now, I heard they can only make like 50 a day {not sure how true it is} but when ever they come in I try to buy them up... Alphas on the other hand are about the same price {little cheaper} and in stock everywhere...
    This post was edited by an admin on May 10, 2013 8:35 PM.
  • SWEI SWEI @ 12:27 AM
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    Idiotic oversized boiler pumps

    Are hardly unique to TT.

    I suspect a perverse relationship involving fossilized engineers and a lawyer or three.
  • heatpro02920 heatpro02920 @ 7:49 AM
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    Swei - I still find it hard to ignore

    obviously, even me and you had a conversation about sizing the pumps on the 175 if you recall...

    Even with my experience- a 1/4 dozen support techs, a factory rep/designer and the instruction manual will made second guess myself...

    This next heating season will tell the tale, the first full one after an equipment change always does, maybe that super high flow is needed to keep the exchanger self cleaning as I was told on a couple occasions and the ones that we are installing properly' sized pumps on will be clogging up after 5 years? Who knows, only time will tell. For now I am happy with the Alpha on the primary, and if the case where you need heavy flow arises you can always ramp it up to high every other season.

    One of the other issues is, you do want to be safe because not only does returning to change something cost you money {a 1 hour call back {unbillable, our fault} adds around $68 to an installation, not to mention you send back the installer that is most likely on an install and more important than the time and money is the customers "FAITH" you loose it when you have to return, now instead of them being confident that they hired the rite team and they got an A+ install, you are back there with in a week swapping parts, they lose confidence in you and the equipment, now they are looking for mistakes, going on internet forum/boards asking questions and showing pictures. This is not good for anyone, so we rely on tech support and installation manuals while of course falling back on our experience and built in know how {because we all know install manuals can be wrong, you may recall my posts about the purge station in the tt solo manuals}... A new tech or DIY'er is going to install that all wrong and then after its full of water have to repair it if they are smart enough to find the problem, just turns everything into a mess...
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