make up water / air eliminator location with buffer [point of lowest pressure]

Gordy

For some reason viessmann never finds a reason to go 10:1 TDR, and get the low end modulation down in the weeds. 12k I believe is it. On their smallest vitodens 200. Is that saying something about our zoning passion here in the states?

Or even drift away from their higher head HX. However the 300 seems to indicate its HX has less pressure drop.

hot_rod

It's been such an uphill battle to get TRVs accepted here. It has to be one of the most overlooked valve in the industry.

A non electric, proportional, temperature activated control and balance device. Inexpensive to boot!
Pair it with a V/S P circulator and it may be the ultimate package.
No wiring, inefficient power hog transformers, relays overwhelming digital "smart" thermostats, etc.

Instead we go through all sorts of gyrations to try and get a handle on bang bang control of our hydronic distribution. Or misunderstood ∆T control of distribution.

No wonder it 90% forced air heat.

Tim Potter

"Don't zone a mod-con. Simple. Use TRV's on the emitters and get the reset curve so the TRV's are 80% open."

That would work for new construction, but how does that mesh with a retrofit situation. Would Uponor t-stats with their PWM control as the temp gets towards setpoint be a solution?

Gordy

hot rod said:

It's been such an uphill battle to get TRVs accepted here. It has to be one of the most overlooked valve in the industry.

A non electric, proportional, temperature activated control and balance device. Inexpensive to boot!
Pair it with a V/S P circulator and it may be the ultimate package.
No wiring, inefficient power hog transformers, relays overwhelming digital "smart" thermostats, etc.

Instead we go through all sorts of gyrations to try and get a handle on bang bang control of our hydronic distribution. Or misunderstood ∆T control of distribution.

No wonder it 90% forced air heat.

And how many non electric trvs can you buy for the cost of buffers, and fancy pumps....... Everyone associates trvs with radiator emitters. Could not be farther from the truth.

hot_rod

Tim said:

"Don't zone a mod-con. Simple. Use TRV's on the emitters and get the reset curve so the TRV's are 80% open."

That would work for new construction, but how does that mesh with a retrofit situation. Would Uponor t-stats with their PWM control as the temp gets towards setpoint be a solution?

No doubt having a clean slate, new construction is desired

There are a handful of retro fit products for TRV use, it depends on heat emitters, piping or access to, it is always worth a look.

Sure you can sneak up on room by room or even loop by loop control comfort with other more $$ methods.

Tinman

Not this last church, but the one before that, we retrofitted radiators with Danfoss TRV's and home-runned each back to the boiler room. Tim ran all the PAP solo so it can be done. No thermostats anywhere.

keyote

Ironman
Thank you While i definitely wasn't saying heat load calcs were not important. I think i understand now whats going on. The radiant heat industry and to some etent related technologies like modcon manufacturers are full of BS they are making promises and implying abilities that dont exist.
My house is twice the size of a new average american house which are probably twice the size of of a european house or an old american house. And yet even with the newest 10-1 modulating boiler [which as far as i know you can buy a boiler that will fire less than ist 8.5-8.2 lowest],and radiant heat system, i can not zone less than two entire floors, half the house comprising two rental apts and one floor of the owners triplex.
You have explained it well, I get it i now, and feel foolish for having ever fallen for all the marketing about manifold actuators, smart house thermostats, zone valves, and system controls etc its all BS, the only way that works is to undo all the efficiency gains and install buffers and run multiple pumps and all the other workarounds. In fact a smaller house of say 1200 sf if its well insulated is wasting money on insulation because its certainly going to be opening windows to keep from overheating on warmer than design days.The term zone zone control etc should be illegal as false advertizing except on commercial systems.

"The entire house looses heat proportionately" ah but it doesn't, the 2/3 underground english basement and the top floor are worlds apart, the front rooms with large southern glazing and the interior rooms with smaller glazing shaded by the 4 story building 10 feet away are worlds apart.

Ironman

keyote said:

Ironman
Thank you While i definitely wasn't saying heat load calcs were not important. I think i understand now whats going on. The radiant heat industry and to some etent related technologies like modcon manufacturers are full of BS they are making promises and implying abilities that dont exist.
My house is twice the size of a new average american house which are probably twice the size of of a european house or an old american house. And yet even with the newest 10-1 modulating boiler [which as far as i know you can buy a boiler that will fire less than ist 8.5-8.2 lowest],and radiant heat system, i can not zone less than two entire floors, half the house comprising two rental apts and one floor of the owners triplex.
You have explained it well, I get it i now, and feel foolish for having ever fallen for all the marketing about manifold actuators, smart house thermostats, zone valves, and system controls etc its all BS, the only way that works is to undo all the efficiency gains and install buffers and run multiple pumps and all the other workarounds. In fact a smaller house of say 1200 sf if its well insulated is wasting money on insulation because its certainly going to be opening windows to keep from overheating on warmer than design days.The term zone zone control etc should be illegal as false advertizing except on commercial systems.

"The entire house looses heat proportionately" ah but it doesn't, the 2/3 underground english basement and the top floor are worlds apart, the front rooms with large southern glazing and the interior rooms with smaller glazing shaded by the 4 story building 10 feet away are worlds apart.

Your comments about the industry are unfounded and way out of line. You haven't fallen for marketing ploys or schemes. You dove into waters that were way over your head and now you're upset with the owner of the lake because you were allowed to swim there.

The technical info that manufacturers put out is intended to be used by people that are trained and competent in designing and installing systems that will use their components. Though you are to be commended for coming here and seeking to learn what you can, that doesn't qualify you to be a designer. You could go to medical sites and gain a measure of knowledge, but that would not qualify you to practice medicine.

The people on this site have been very kind and spent a lot of time trying to help you and now you rail on our industry??

You made the decision to play hydronic doctor and now you're upset with the industry because your patient isn't doing well. Man up and take responsibility for your own choices.

keyote

Ironman Please dont take what i said as a knock against actual radiant professionals.

SWEI

A properly designed, installed, and commissioned radiant system for a small house should not need much (if any) zoning. We zone for two reasons: external heat sources (think solar gain or a woodstove) and intermittent occupancy (think guest wing, studio, or shop space.)

The overwhelming majority of European systems are based on panel radiators and TRV's. They design their boilers to work with those systems. Many of the mod/cons sold in the US are manufactured in whole or in part in Europe. The mod/con boilers made here (or even in Asia) contain a lot of European-made or European-designed components.

SWEI

I should have added that by 'intermittent occupancy' I mean 'unoccupied for several consecutive days' not 'unoccupied while I go to work.'

keyote

Thanks swei ironman makes a similar point and after a month of trying to make it work i get the problems my point was if with a 5000 sf house and a 10-1 modcon i cant zone without all sorts of work arounds like buffer tanks whats the guy with 1500 sf house and a boiler selection from last year going to do. My other point is there is A LOT of marketing directed at consumers that pretends this is not the case that radiant with low mass wood floors and actuating every loop is an everyday event.

SWEI

The RPA was created in large part to address this very issue. Properly trained designers and installers are critical to the success of a heating system. Manufacturers market components. The consumer press doesn't really understand radiant heating at all, never mind human comfort. Then again, neither do the majority of US contractors.

Rich_49

Keyote ,

I just designed a system for a 5 story Brownstone in Brooklyn . I guarantee there will be no problems short cycling in that system . Basement has panel rads , first and second floor have panel rads and radiant , floors 3 & 4 have the old cast iron radiators and are on one zone .

Your house is not that different from many others . What is different is what your decisions were based on shooting from the hip . All these gyrations and different opinions and you have not I fear HEARD what has been said . You really put alot of stock in what a few said . Maybe you should have researched the people who have been talking to you and figured out who was who .

What you don't know is that 90+% of the guys in the hydronic trade don't have a damn clue , some even after doing it for decades . Many here even do not get the house as a system concept , many think they do but don't really . Some are salesmen although they have different misleading titles . Some quote other folks work as if whom they are quoting is God himself .

Maybe that's where the problems lie , sometimes the best solution to a physical problem does not require mechanical things . Instead they need to be thought about deeply and proper measures be taken to address them . That is where most guys fall short . My suggestion to you is , Read all the posts you have started , figure out who is who and begin to think that your house is not that big a mystery . You have been shown equipment that is not right for your application and what nonsense it takes to get it to do what you want . You have also now been shown equipment that was designed for your specific set of problems . You have also heard me bashed and insulted by one whom does not even participate in our daily grind with the exception of having a diploma that states he is an M.E and being a regular poster .

It seems as if you believe you can learn this in a few weeks or months , fact is , it aint gonna happen . You probably have 3 years worth of reading to do for 8 hours a day and if you're real good you won't make 10,000.00 worth of mistakes .

You say you cannot afford a designer and I ask , can you afford to not seek one out ? have you contacted any designers even ? Good luck with your venture and if you'd like , give a call , I might know a yound designer from right here on the site that does work in Brooklyn . Of course you would not want me because as others have told you , I am not the designer I think I am , as if I thought I was a certain type of designer . LMFAO .

keyote

wow rich Where are you getting that if I were to get a designer I have already thought it would be you. Its what i was saying to Gordy, that i understood and agreed with him that you would be an excellent choice but that im running on fumes.
Its true this is a lot more involved than i was led to believe by reading about radiant for the past 20 years and doing one small radiant zone in an addition i built someone.and tons of plumbing and hvac work. I am in the trade and do a lot of this type of thing and think i have learned a lot in the past month.

I apologize for being so resistant to just taking direction without understanding but i must understand what i am installing as i said i have ENTIRELY BY MY SELF gutted and designed and renovated two apts and the new MEP from the cellar up. so I am not only not able to afford to sub this out i am all too aware that

" What you don't know is that 90+% of the guys in the hydronic trade don't have a damn clue"

So I felt with some effort i had a much better chance of figuring it out than subbing it out. My only real mistake so far was relying on information i learned 5 years ago when i started this project and buying the used TT110 from that info. besides the 5 page 80% vote for the TT still up on this website that decision was based on I could find no heat calculator to plug in my atypical construction methods and wrongly thought over estimating the load was the safe way to go with a modulating boiler.
That's cost me 1200, less what i can unload it again on craigslist for.Loopcad was my heat loss solution which i hope is accurate, at least i was able to manually approximate r factors of wall composites etc.
Thanks to you and the others i have learned [in short] the low mass, small zones, are always a difficulty usually solved with buffers, that P/S is the safe way to avoid the low flow issues. And its true you and others said as much in probably the first post i made and i needed to go a month learning why. sorry that's just how i am. Now i know why and yes you guys were right from the beginning which i never doubted but needed to understand. You have to admit the radiant industry markets to diy types and implies things that are not true while the green building community are cheerleaders you think you could trust since they have all those degrees and a bias for efficiency.

Maybe you mean my choice to go with radiant? well I haven't been totally convinced it was a bad choice yet, but i certainly am more aware of its limitations and much of my frustration you guys took as obstinacy was due to the radiant and green industries lack of putting those limitations front and center and being surprised to find them out.
I think all of you guys have pretty much agreed on what i should do it just took a while for that to become apparent because you each focused at times on different aspects of the problem at some times one would try and help me find a work around while another would suggest i let go of certain premises like the boiler i bought and reconsider. In the end all of you were clear it came down to low mass low load etc, and even then my wanting to not play it safe but rather push the envelope.
Can you blame me this is the last house Ill ever build [probably] and i want it right yes i cant afford not to have a designer because youre right its a lot more complicated than i thought and i wont get it as good as you will but the reality is im putting the boiler on a credit card and hoping you guys will bear with me on the blog advice.
So what do you think, spent all day looking at your favorite boiler the versa hydro mostly because of your gas bills and seeing it kind of answers a lot of issues. its seems safer play than seeing if i can get away with direct pipe the KHN because its a buffer as well. but then i realize the dhw is a lot less than the smart 50 and that the 10-1 modulation is kind of a misnomer. i cant help but wonder if its that different from putting a buffer on the TT110 or the KHN if i need to.Well yeah its a nifty combination all figured out and i've wasted a lot of time but i also started looking at it thinking HTP was a economical brand but have concluded this unit is probably even more than the KHn maybe even more than the KHn and a buffer tank.
I have bit my tongue but Im going to say this I really doubt anyone takes your and Hats feud as anything but personality crap. you are obviously a well respected busy hydronic designer who says tons of intelligent stuff, and Hats an ME that has his own expertise they dont conflict or contradict or trump just because you two disagree about a particular job no ones using that to rate either of you, i really wouldnt worry about it. i can tell the other guys respect your ideas, as a potential client and an informed one it hasnt made me think you any less competent because you guys hate the **** out of each other, its funny. And im not judging either of you for hating im all about resentment its my favorite pastime so hate on.

Rich_49

Just wanna hit on a couple points . I like HTP because they have a product for basically every problem that arises . They are not an economical brand by a far stretch of the imagination . They have only recently started having a couple units built overseas as after years of research and attempts the owner reached the conclusion that it could not be built here cost effectively enough to compete with the Korean stuff with which he wanted to offer a better product than . HTP was also the first company to build and market a mod con boiler in America . Unfortunately since3 it was the first it had issues and would seem that it was the worst when in fact as it turns out maintenance (lack of) , piss poor installs and lack of understanding of many of the things discussed here crushed it as well as other manufacturers Giannoni offerings .

I don't have a favorite HTP unit and in fact I design around and install many brands whom folks prefer as long as they will work properly , I walk away from many uninformed builders , contractors and homeowners whom cannot be talked out of poor choices made at the behest of others before contacting a designer .

As far as Hatt and I go , it may seem as though we hate each other and quite possibly may at this point but as you can gather it was not always so . What transpired within your discussions was illuminating at a minimum and was certainly frustrating . As far as what people think of my theories ( tried and tested) many will attest I care not . Many do things differently than others and in the end if the results are favorable and the customer is happy that is all that matters , some of us want the customer to be happy out past 4-5 years and strive for even greater comfort and efficiency . I am not here to badmouth anyone , but am here more to make people think outside the box to build very good , simple , efficient systems and not just buy the boiler from the guy with the shiniest brochure and fastest talking rep agency guys . Another is to point out flawed advice or misinformation whether it comes from a good place , a misinformed place , an ignorance place or a place that has nothing to do with one type system as opposed to another in which neither share any commonality . I know what I know and try to share with others , whether or not they are receptive is on them , I do not speak about things which I do not know through having already done it several times and it working .

I can get behind someone wanting to know , it was not until many years into my career that i figured out that most salesmen and reps could not help me with my systems and were full of dog excrement . In fact I would confidently state that out of all whom I have encountered there are less than 2 dozen tech support , rep , trainers that can give you any competent help and 2 of them are retired , only one is still visible or heard from on any regular basis .

Fact is after 30 + years doing this and only this I still learn something everyday and continue to add value for my customers . Never forget that you never know everything , it's done too often . Never stop striving for perfection , you'll never achieve it but on the way you'll discover what works well and also that what works well in this building will not in another .

keyote

Thanks rich monday ill see just how expensive this versa is compared to the loch and possibly the loch with buffer

hot_rod

The all in one style do have pros and cons like all your choices. Any time you have a flat plate HX in a system that sees potable water on one side you will have to clean and maintain that HX, possibly yearly. All the small passage ways, provide the large HX surface area, and places for mineral deposits to collect. Cleaning frequancy depends on the hardness of your water, how much runs through it, and how hot you run.

Like a tankless heater, it is nice to have Webstone purge type valves on the DHW side to easily run a cleaner through it, maybe HTP includes them?

I like the concept of DHW with a plate hx, just know the limitations.

I used a HTP Solar Phoenix for 7 years in my shop, a fine piece of equipment, and installed many Munchkins in my area, I have no hesitation to recommend that brand.

If you step back an look, the boiler, buffer and indirect you have it is essentially the Versa, but in 3 piece.

If you like, or want the features of the Ramp delay, adjustable delta T and ability to go online for control, etc I think the KHN is top of the game, currently. I'd guess more installers realize the advantage and benefit of those features once they buy a product without them, especially if you want to tinker, have a lot of adjustability, and chase ultimate efficiency.

hot_rod

SWEI said:

The RPA was created in large part to address this very issue. Properly trained designers and installers are critical to the success of a heating system. Manufacturers market components. The consumer press doesn't really understand radiant heating at all, never mind human comfort. Then again, neither do the majority of US contractors.

Two thumbs up to the RPA, it has a lot to do with the fact that we have knowledgable designers, installers. Just not enough of them.

I'd add that a handful of the top hydronic manufacturers do more than push components. A large part of their budget goes to training the industry, to keep it up to date and a viable industry. Some of that training is at no cost to anyone that asks

Gordy

For the installer to have the ability to remotely monitor, adjust, and check on their installed equipment is a huge asset, and time saver. At a premium cost though to the homeowner.

keyote

Hotrod
Versa is new concept to me after watching, reading what they have up this is basically what i think it is.
a 5-1 mod con SS DHW tank and a Ch loop with heat exchanger that draws heat from this.Its the ability of the Ch pump HX and loop to adjust how much heat it absorbs that they claim as a 10-1 ch modulation, I cant figure out if its brilliant or a gimmick or if it depends on you design. In other words as you say a loch a buffer and a indirect add up to the same. certainly the indirect will give me more dhw and the loch has more control. Obviously is definitely a 2 pump system but is it going to do as well at modulating and condensing since it pretty much always in dhw mode?
Hats comment about the loch w buffer as best choice worry me. I thought the consensus was i had a good chance of not needing a buffer with the loch, so only mentioned it as a contingency. While its true that if the versa is AS efficient as the loch/ buffer/ indirect option AND has the buffer contingency included no risk of failure is a selling point,
But the lochinvar selling point over using the TT110 was not needing a buffer, that the cost of buffer mixing and what i could unload the TT110 for would pay for the loch and be a better option.
So My question is i cant make a call without understanding how realistic the lochinvar without buffer is in order to compare cost, then understanding how in my particular situation the versa does on energy consumption of the likeliest loch configuration.
In short it occurs to me maybe i should just go back to the buffer with the TT110 for now and swap for a lochinvar when i can afford the upgrade. right now the TT110 is installed and the indirect S/R piped but the CH on hold.

Rich_49

keyote said:

Hotrod
Versa is new concept to me after watching, reading what they have up this is basically what i think it is.
a 5-1 mod con SS DHW tank and a Ch loop with heat exchanger that draws heat from this.Its the ability of the Ch pump HX and loop to adjust how much heat it absorbs that they claim as a 10-1 ch modulation, I cant figure out if its brilliant or a gimmick or if it depends on you design. In other words as you say a loch a buffer and a indirect add up to the same. certainly the indirect will give me more dhw and the loch has more control. Obviously is definitely a 2 pump system but is it going to do as well at modulating and condensing since it pretty much always in dhw mode?


Hats comment about the loch w buffer as best choice worry me. I thought the consensus was i had a good chance of not needing a buffer with the loch, so only mentioned it as a contingency. While its true that if the versa is AS efficient as the loch/ buffer/ indirect option AND has the buffer contingency included no risk of failure is a selling point,
But the lochinvar selling point over using the TT110 was not needing a buffer, that the cost of buffer mixing and what i could unload the TT110 for would pay for the loch and be a better option.
So My question is i cant make a call without understanding how realistic the lochinvar without buffer is in order to compare cost, then understanding how in my particular situation the versa does on energy consumption of the likeliest loch configuration.
In short it occurs to me maybe i should just go back to the buffer with the TT110 for now and swap for a lochinvar when i can afford the upgrade. right now the TT110 is installed and the indirect S/R piped but the CH on hold.

The 10:1 claim comes from the fact that the Versa's on board circ is controlled similarly to what everyone has touted , a VS circ which varies flow based on the heat transfer between the system and source . this source , as opposed to being the boiler while running is the mass in the tank . The system in Michigan uses a Versa 130-80 .
By increasing the mass one can increase the time between calls for the combustion assembly to intervene in the process . The 130 model also will only provide a claimed max of 100 ,000 BTUh while the pumps control will allow it to go as low as 10,000 or translated as 1 gpm on the tank side , with a 20* Delta on the system side they will be in lockstep as programmed and if you use 10* on the system side the onboard circ would flow 2 gpm as it recognizes the return water temp and the supply water temp . With attention and proper design and a knowledge of what unit you want to use's capabilities you can do damn near anything .
This is not a gimmick as much as an option to buy one piece of equipment with all the controls built in and saving space . KHN and your indirect would cost same as Versa , now add you buffer , cost , space and labor and the Versa clearly offers HUGE value .
I have at this point used dozens of Versas in many different applications and have yet to encounter a problem . I even have a Versa Solar on a geo thermal job I came into after a poor design . Long story short , oversized Bosch TW122 flowed entirely too much fluid on the system side (25 gpm) . !2 gpm went to a Caleffi 120 ThermoCon and the other 12 went to the solar loop . Versa also takes over heating at 42* through the number 5-6 tappings on ThermoCon tank . eassy controls , no complicated trash and low maintenance .
I beleive you are NYC so water quality is not a huge issue but the FPHX should get a good flushing every 2 years or so but the real HX in the Versa is the only one of it's kind and will last for years . It's cupronickel construction expands and contracts upon firing and shutdown and any garbage that would adhere or collect to others heat exchangers will fall to the bottom of the tank and can be drained from the drain cock . You couls also almost say it is a 2 pass HX as the hottest flame goes up through the center of the water column and then back down through the outer tubes and exhausts from the bottom . Just sayin .

As with any system , the Versa is not always the right choice based on system needs , budget , customer expectations . I would state that anytime one requires a mod con , buffer , indirect the Versa should always be looked at as an option .

hot_rod

As Hatt described all this is unknowable until the system is up and running. Solar gain, internal gain, occupant want and needs, calculation error, climate change, etc.
That is why I like the ability to electronically derate the boiler, as the Loch can do, and or the buffer so IF that one smallest zone calls, on a less than design condition, you still have some short cycle protection.

Grab a piece of paper, write down the 3 or more options, put a pro and con column next to those and make a decision. Every system described and considered will work in your application, so maybe it comes down to a $$ choice?

keyote

Thanks Hat, The 16 zones was back when i was under the false impression that all i needed to do was screw an actuator on to the manifold for every loop and stick a wireless tstat on the wall of every room. Fortunately the good folks at heating help dragged me kicking from my delusion and explained the implications which you outline in that last comment.

More recently i have been referring to 'zones' meaning the manifolds on each floor and using the total flow and head, loop cad gives for them for design day, since they all were over the lowest mod of the lochinvar and having their own riser to the cellar which i could put a zone valve on I thought i could make do with them as zones.

But then it occurred design day was not the problem, it was 65 degree day (some have said i could make this a bit cooler still) that would have calls potentially lower than even the lochinvars 8500. So i re ran the heat loss as 65 degrees and sure enough 1500 cellar slab - 6000 top floor were the results.

Before deciding what to do about the zone situation i tried to ascertain if zones were ganged either through boiler staging or piping or controls solving the problem of calls for less btu than low mod, would the low flow and pump remain solved. It seemed it would because pump cant pump less than boilers minimum requirement so if the 8500 btus were absorbed i was good.In the process gordys charts seemed to indicate if i could pull this off you could be more efficient at mod con ing.

so then I pondered that if i were already giving up loops/rooms as zones and resigned to to ganging [riser/manifolds/floors] into zone did i really care if if i went farther and made it two floors or even all four and it didnt really matter anymore. so i was settled on 2-4 floors as a single zone to avoid a buffer and P/S and two pumps.

But wayyy back when dealing with the TT110 and zoned loops scenario I wondered, having no practical experience myself, how likely was it that so few rooms would call for heat at any one time to be under the lowest mod. I think the answer is its impossible to predict, even knowing the house it will vary by time of day season occupancy activity, and the bottom line is if it can happen it will happen.

That said i dont currently have four floors ready to go on line i have only the highest load top floor radiant and plan to gang the lowest load floor the cellar, by flushing and using an abandoned finn tube system down there, combined i think it will put me comfortably over the 8500 btu even if i have to hold starting to heat until it cools a bit more than 65 degrees.

so i guess the answer is I gave up zoning when it became pointless when i couldnt zone rooms. i felt better about that when i saw gordys charts.Obviously the versa might open up the possibility again. But that leads back to the question of if all things are equal you have the loch without buffer or P/S and the house as a zone, you have the loch with a buffer or the versa, which is more efficient because thats what the zoning costs [assuming i actually can use the loch w/o P/S and buffers if the house is 1-2 zones. other wise its which is more efficient the versa or the loch buffer indirect

keyote

Rich gimmick was a bit strong and i tried to qualify it, My worry was looking at gordy's charts on modulation and condensing before the versa came up, it seemed i was a textbook perfect scenario with the KHN 085 always modulating between 10 and 60 % and RWT between 80 and 117,(except when heating indirect) And it seemed the consensus was if i were willing to gang the floors together to guarantee minimum flow and BTU absorbtion, i didnt need to buffer or P/S pipe. So I wondered if the versa really could be as efficient as that or only a little worse but offering several other benefits.

It has the auxiliary taps, and a solar coil option,it takes up less space, it require less piping, and it probably would again open the possibility of zoning loops again. If i were wrong about not needing the buffer and P/S it has that covered.

Im not sure how much the second pump and using the indirect as a heat source equates in my particular scenario, my thought was its not going to condense as well on a radiant system but my non expert guess was its going to by really a close call but id like to hear you guys guesses.
Right now I have a brand new unused TT smart 50 I already piped to the TT110 and the house,so the cost comparison I was hoping was; skipping the cost of a buffer and mixer for the TT110 and selling the 110 with the old smart 30 and trim, and those about equalling cost of a lochinvar.
So lochinvar alone vs the versa.
Now if im wrong and the Loch will actually require a buffer and another pump then its a closer call cost wise Im guessing.

But then i wonder if the buffer is needed even with the loch, I might be able to just make do with buying only a buffer now and using the TT110 for a while and get a loch later.
The versa solar is tempting but no doubt even more money.anyone know costs?

keyote

Hot rod
we were writing the same thing at the same time Im not sure of versa cost yet and im not sure of efficiency comparison on my system, its true i cant predict how zones or rooms will time their calls at this point but i think if loop cad is right i have a pretty good idea of what mods and condensing will look like -GREAT.

My guess about how rooms will react is they will have very un even heat loss. its long narrow and tall building so some rooms have lots of well solarized glazing and others are more interior small rooms with glazing shaded by the four story building next door, the top floor has the most solarization, but as you say who knows i can see the end rooms calling for heat a lot but the interior rooms soaking a lot of it up without calling themselves as often, I can see the cellar is not only low load because 2/3 below grade and a slab but i didnt even draw a loop in the center because the boiler and piping i think will do most of the heating. it was one reason i went ahead with the used TT1110 was a cheap way to experiment and see.But not if i have to add things that wont be used later.

keyote

Hat LOL yeah i know im kind of crazy and have this sunk loss thing going on where the more minutia I have had to learn the more im damn well going to make use of it.
But you got to admit you all fed me the stuff I worry too much about.There was a time i was going to just throw the damn TT110 up and see what happened.
Your little lesson there was very very helpful I am trying to figure out just how much i should be concerned and how much you guys are just being thorough in educating me, and even if i were to throw the damn TT up it would still be worth knowing all i vaguely do now know as i watch (on my spackle bucket) it perform and think about how it could be improved or what should replace it. And as i finish the rest of the system and consider the controls to get this running.
Ironically it was probably your situation that made be get so anal i was terrified id have two tenants demanding heat and rent striking while my boiler was having a nervous breakdown.

Gordy

Running you through the gauntlet really at the very least made you think more deeply about hydronics. It's a science with many variables to try, and make constant.

If it were me you have the tt. Use it. Monitor it. Plumb for a buffer just in case, but don't install. Not yet. See how it behaves, and save your money for now. Then you will learn even more.

keyote

Thanks gordy I dont regret the learning at all I find hydronics fascinating. I had planned to research in a more methodical and broad way but the time got away from me and cash tight and suddenly i was signing leases without a boiler installed making it a bit stressful.