TT-110 Delta-T?

Jimbo_5

Have a TT-110, using ODR,  and have been seeing a Delta-T of 20.  But I have heard that a higher Delta would be better.  My circulator has been operating in the High position.  Would it be better to try the medium or Low selector switch position?  Or am I barking up the wrong tree?

Unknown

Delta-T of 20

20 is nice,,,, it was(and still is) the standard for designers!

But modcons love cool return water, if you can slow-down the circ to increase your Delta,,, AND still have enough heating capacity by the time it gets to the end of the circuit (without short-cycling) your efficiency will go even higher! :-)



I would say go for it,,,, you can always go back! 

Jimbo_5

Thanks, Dave

I did try it, going to the medium setting on the circulator.  I now range from 20 to 25 between supply and return.  However, I am getting a bit of chatter, I believe it is the flow-check on the return line.  The radiators still get good and "hot."  Here on Staten Island the temp is about 28* and my supply gets up to 144-ish before modulating down to circulate on low-fire.  I think I may try the low setting?  We are supposed to go single-digits tonight, so it will be a good test.

Unknown

flow-check on the return line

Why do you have that?

You could just add a push-in plastic one on the pump(located within the cabinet).

Also, have one on your domestic circ. :-)

Jimbo_5

Thanks

It is what TT called for in their specs.  One on the return piping and one on the piping for the Smart-40 indirect.  Kind of "clunky" in size and price, and they don't appear to be able to open very much, but that is what they called for.

Unknown

Understood

I think some "updating" with TT instructions need to be done.

IMO they were very "leery"(in the past) of the reliability of these push-in C/V`s, but they have proven themselves nowadays. :-)

Jimbo_5

Interesting

I do not believe I have seen or used one of them.  I cannot picture what it would look like.  We often use brass spring-loaded check, or regular checks, with the brass flap. on condensate lines.  But I am always looking to learn something new.

CMadatMe

Delta-T

Here's the problem with the application in this case. I'm going to bet you didn't pipe with a low loss header. This would have significantly help you in what you are trying to accomplish. Primary/Secondary is useless in my opinion for a mod/com Why? You don't have to worry about the head of the boiler only the system side when sizing a system circ.  If that circ is a 3 speed Grundfos it's equiv to a Taco 005 on speed 1. Your delta-t is going to be dictated by your heat loss and most importantly the heat loss in each zone. On a 30 degree delta in a baseboard application you must use the 160 degree water output of the board in order to size the board to the heat loss. In my opinion scrap the delta t idea and use a grundfos alpha or another type of delta-p pump.

Jimbo_5

Thanks for the imput

I did not pipe p/s because of the large supply & return piping (2" black pipe) running from the boiler, S&R teeing off 2 feet from the boiler and going toward opposite sides of the house.  I have ci rads (9) and about 20' of ci baseboard.  It's a 1939-ish house and the emitters are over-sized by today's standards, so I suppose my water temps can run a bit lower than what they used to prior to the new TT-110.  No zones for now, just an old 2-pipe system.  If it were not too late in the season, I would like to cut into the return piping and go with a reverse return, now that I understand it a bit better.  My home system is a "work in progress."

Unknown

Chris (utmost respect intended),,,

How would you even know that???

Jimbo asked a simple question,,,, so I gave him an easy answer,,,, why are you going-off into wild pump-changing tangents?

In his situation, he may not even need anything!

Mark Eatherton

Primary/Secondary is useless in my opinion for a mod/com Why?

Splain your position Chris...



I once told Siggy through an associate of ours that LLH were for people who didn't know how to do P/S piping.



If you are using a LLH for air and dirt elimination, then they are better, but if all you are trying to do is hydraulic separation/disconnect, they are the same, no?



At significantly less expense.



ME

Jimbo_5

Please excuse my confusion

Thank you, Mark, but I do not know what LLH is.  Can you explain please.

Unknown

Jimbo

A LLH is low-loss-header,, and you don`t need-one! :-)



Your on the right-track with everything you have now,,,, don`t let confusion take over!

Jimbo_5

Thanks again

Thank you for the explanation on LLH.  How about the check valve?  Any way to improve my system is gladly appreciated.  Life is to learn.

Unknown

I looked,

but I can`t seem to find a pic of this,,,,, next time you are at a wholesaler ask to see a 15-58 and look-at the outlet side, then you`ll know! :-)

Jimbo_5

Ok

I certainly will.  If this will help me get rif of the big red check in the attachment, I am all for it.  I am getting ready to install the Smart-40, perhaps I can do away with  the flow-check here also.  I purchased the bulb kit to run the tank through the boiler panel, but for now I guess I'll just use the enclosed wiring.  My TT-100 is new, but it is the older version with the first control panel.

Jimbo_5

On 2nd thought

I just went down and looked again at my piping, and it appears that the big red check is there, where it is, to keep the system "in check."  But the one for the Smart-40, might just work at the circulator.  I was planning upon a 007, but just may change that for better flow to the tank.  Live and learn.

CMadatMe

Mark

Your the professor.. No? only kidding... I soak up your posts like a sponge...



I type this once and was booted so I'm double dipping.. I would like your input on this subject as well.



Yes. You are seperated in the aspect that no pump has any influence over another. Add  the boiler protection it gives you and that's where it ends. I like to have consistent water temps across my zones when multiple zones call and you know (your testing me) that with prim/sec  you have temp drops across each zones supply side when multiple zones call...



If I can have control of my water temps, I can have better control of my delta-t. Meaning that I know what is going in and what is coming out consistently.  To me the design phase of a project is the most important phase and a LLH gives me total control where as primary/secondary does not.  They also give me on average a 10 degree temp difference between my boiler temp and my system side temp which also gives better comfort control never mind better system efficiency.



As you know I am a big Viessmann guy. They to the best of my knowledge are the only boiler manufacture that promotes and recommends LLH for their mod/cons. Do you think that temp sensor that sends feedback to the boiler control has influence on the boilers modulation? Sure it does...



What are your thoughts? Do you not feel they are a better alternative to prim/sec? Do you feel they give you better control of the system side?

Unknown

Jimbo

Threaded flo-checks have their place,,,, but not needed everywhere.

There are +`s & -`s to most things,,,, don`t start "second guessing" yourself,,,,, you ARE on the right track! :-)

CMadatMe

No Offense Taken

No tangent...Yes you did a fine job. Just my 2 cents...

Mark Eatherton

My thoughts on this...

LLH are really nothing more than a fat spot in the pipe where two streams combine, thereby exchanging heat. And yes, you are correct, the big V is the ONLY company I am aware of that promotes their use. They also sell them. With that said, I have installed three of the biggest Vitodens available as primary/secondary, using piping, and not the LLH, and placed the system sensor down stream of the last boiler connection, and it works just fine.



Now them thar Caleffi LLH offer something that a big fat spot in the pipe DOESN'T offer, that being segregated flow in addition to a LL circuit for the boiler primary. Those in my opinion, are worth the money, but even they have their limitations that good old copper tubing doesn't .



If there is a labor savings to be had with any item, and it can be proven that the material costs don't exceed the labor savings, then I am all for it. Again, if it does the function of more than just a pipe, i.e. air separation, dirt elimination, expansion tank connection and sensor well, and low loss header then it probably IS worth the time and effort to install it.



But if it is nothing more than a fat pipe with two devices connected to it, I can do it with fittings for less money, and just as fast as doing a LLH.



That's my take :-) And as usual, I am ALWAYS open to other ideas.



ME

SpeyFitter

How good are LLH's, really?

The biggest "selling point" I keep hearing about low loss headers is how they can replace an air seperator AND a dirt seperator.

BUT my question for you guys is do they really do as good of a job as a true designed air seperator, and a designed dirt seperator?

Also, one other thing that would be nice to see from boiler manufacturers is variable speed pumping controlled by the boiler - at least the main/boiler pump controlled to vary speed of pump. Then they can vary the pump rate by the modulate range. I know of one boiler that offers this that we mentioned before.

OR how about a pump system that links a variable speed secondary pump (e.g. Wilo stratos, grundfos alpha) with the flow of the boiler pump. Of course their pressure drops of their loops/systems are different, so some balancing may be required, but it would be interesting if a feet such as this could be accomplished to match flow rates for better delta T's.

Hell why do we really need primary secondary pumps or LLH's? Why not a variable speed pump that pumps on demand. Then you know you're always going to get the lowest system return temps directly to the boiler. Have a parallel system. Sorry I question everything.

Wouldn't a pump through one pump system guarantee the lowest temps always return to the boiler? Why are we messing with this hydraulic seperation crap?

Devan

Buderus LLH

No longer just Viessmann, Buderus now supplies and requires the GB142 be installed with the LLH. The got rid of that pre piped Pri/Sec manifold they use to supply.



FYI

CMadatMe

Hydrolinks

Funny that you bring the hydro link into the thread. I have been doing some reading on them. Great alternative when zoning with pumps. Price is right also. You can't build a header, air elimination and pri/sec or LLH compared to the price of these. I  found out last month that the exisiting Caleffi Rep was let go and had to wait for the new Rep to get in place who happens to be the Wirsbo, Burnham, Amtrol Rep in my market.  He is now in place and  I look forward to seeing and playing with one. Any past experience with these? Do's or don'ts?



My main reason for LLH's and this proably doesn't apply to most that post here but you never know.  95 percent plus do not do heat losses. They stick a mod/con in an exisiting system and go. We have had a pretty cold winter this year compared to past winters. I have been getting guys asking me why they are getting customers calling and saying that they are not comfortable and a little chilly and it's always when multiple zones call. I say, did you ever do a heat loss? They say, why? It always worked before. So you have to explain to them what is happening with water temps and they look at you like you have 2 heads. They just don't get it. To rectify the problem most fall back to the old aquastat theory..Just turn up the water temp.  Mrs Jones just paid top dollar for a HIGH EFFICIENCY piece of equipment and she expects fuel savings and comfort. I don't see a LLH as a dummies way of pri/sec, I see it as a tool that helps provide comfort and an aide during the design phase.



Taco makes a nice little copper LLH that we have used on the Vitodens 100's but we seem not to be able to get them. They have been b/o'd for a month.

CMadatMe

Variable Speed Pump

Boiler head. Mod/Con have alot of head pressure. You'd have to have a pretty big pump to cover all possible install sceniros. European boiler companies don't provide pumps across the pond so why would they do it here? You could always buy a variable speed pump and do it yourself. All the head loss information for a particular boiler is in the install manual.  You don;t need a boiler company to sell you a pump you need a pump company.



What has worked really nice with no problems or issues to this point for me has been using the properly sized boiler pump, a LLH, Grundfos Alpha as my system side pump and zone valves. 

Mark Eatherton

I think i has more to do with sensor placement than it does LLH use...

What in your minds eye, does a LLH do to enhance system operation?



And, no, I have no experience with the Caleffi product, I just like it's internal baffle design.



So long as the contractor is replacing like size with like size boiler, even though the new boiler may be a modcon has nothing to do with not having done a heat loss calc.



95% of the contractors around here STILL don't do loss calcs. Don't know how, don't have time, or wholesalers can't get to it fast enough for them. That is starting to change in new construction because the AHJ's are starting to REQUIRE one before permit is issued. Not required on replacements...



I have only seen one job where the controls were set so low that the home was uncomfortable. Again, I think it has more to do with sensor placement than it does with LLH use, but that is just my personal experience speaking, Other than Viessmann, Lochinvar is the only other company I am familiar with that has an alternative to using the boiler supply temperature sensor (remote SUPPLY temp sensor). Do you know of others?



ME

Mark Eatherton

How good are MBR's and is dirt separation really necessary??

I question the use of expensive MBR's, and have done so since they were introduced many years ago. All a person needs is a fat spot in the horizontal line, and air elimination vent on the top of that. I have seen 50 year old systems that had exactly that, made out of copper installed, and they worked fantastic.



MBR's were introduce in an attempt to alleviate a condition in the field that had more to do with the pumps location in relation to the expansion tank than it did air elimination/separation. I have seen proof that both the conventional air scoop and the MBR can only take the O2 levels down to a certain point. And yes, the MBR get it to that level quicker, but at what extra expense, and to what supposed advantage?



As for dirt separation, if you don't put garbage in, you don't have to take garbage out. If there is garbage already in the water, I find that a side stream cartridge filter works fantastic for filtering out the rusty floaties in a system, and once cleaned up and proper pH maintained, there is no longer any need for continuous filtration, No filter, less pressure drop, more flow, and more flow is a good thing for the most part.



Now, if someone (Lochinvar) were were to come out with a combination buffer tank, air eliminator, dirt separator, low loss header, immersion control well, then my attitude might change :-)



A million different ways to hook them up. Do what works best for you.



ME

DanHolohan

Once, while in Germany,

I explained primary-secondary pumping to a German engineer and explained how we've been using this piping technique in the U.S. since the early '60s. He looked it over and told me that this wouldn't work, and then he showed me pictures of a hydraulic separator and said that this is the only proper way to do it.



He had never before seen pri-sec piping.



I nodded respectfully and smiled.

archibald tuttle

cowrong me if I'm wrecked

but once we got into con, and certianly in the mod-con era the case for  pri-sec seems to recede a bit with the possible exception of multiple boiler installs.



assuming that the mod con and its pump can handle the entire hydraulic circulation of all loops - which presumably would be a necessary condition to operating the boiler at low temps - otherwise your boiler water would have to be hotter at a lower circulation rate to provide cooler flow to more system circulation ,no ??



I couldn't understand why buderus was supplying that premade primary loop with its GB142 for that reason (of course I couldn't understand why the would make such an otherwise nice and sophisticated heating appliance out of aluminum, but I digress) and now I see on this thread that they have discontinued that practice but specify a LLH.



My principal use for pri. sec has been with multiple boilers and to purposefully keep a hotter return temp for non-condensing oil boilers where my desired system delivery and delta T would return water too cold for the boiler.



But what is really the difference between an LLH and simply ging up several pipe sizes in your manifold areas. and do you also use a LLF, i.e. low loss footer, to collect the returns?



Thx.



Brian