Giannoni HX?

Robert O'Brien

Can't say I'm a fan but a number of manufacturers are staying with this HX. Am I missing something? Are there more Giannoni fans than I think?

SWEI

Ask the bean counters

Sunk costs...

Robert O'Brien

SWEI

Yes,but if you don't sell them,what does that do to the bottom line?

SWEI

Good point

though I'll bet there's a 3-5 year lag before the trend becomes un-ignorable.  Lochinvar would know for sure, given that they offer both designs in similar sizes.

Robert O'Brien

Very true

Why have two boilers with two different HX'ers? Can sell those who have a preference while waiting for the market to make up it's mind?

Mpj

Heat xchaner

Call me naive but I do not see a big problem with these heat exchangers

I have installed a bunch of Munchkins, Alpines and one Elite plus with this type of exchanger over the last five or six years. I have not had one problem with them working wise or the annual maintenance wise either Can you explain to me the problem with them to me?. Is there a big difference between the other types of exchanges then these?

JStar

HX

They are still around so that when the typical uneducated contractor doesn't install or maintain them correctly and they crack, our phone will ring.

Robert O'Brien

Mpj

My objections center on the observed lifespan and need for an expensive power hungry high head primary pump. When there are better choices,why cling to this?

CMadatMe

More The Likely

When looking at it from a marketing/selling stance. Because we preached for years that this was the way to go and to take it 100 percent away and say this is better may hurt the credibility of a mfg with its customer base. So keep both.

hot_rod

plenty of ECM pumps

available to pump those HX. Looks like the Grundfos Alpha would cover some of the Cadet models. I'm sure a Magna or Magna 3 would cover most of the larger sizes. If pumping power consumption is the concern.



Keep in mind any HX will fail if not properly treated inside and out I have pictures of failed Tube type boiler failures, and there is a lot of weld leak potential in the tube type HX, some leaked right from the factory



Not to forget copper tube boilers. Many of them failed within a few years when connected to rubber or other non barrier tube, not the boilers fault. And there are plenty that have been running 20 years and more. It's more often then not about the installation, return temperature protection mainly, and quality of the fluid.



Many of the large 500,00 and up boilers basically pair up a few Giannoni heat exchangers so this type of HX is not going away.

Robert O'Brien

Hot Rod

I hear you but the cost jump to a Magna from an Alpha is huge! I really feel there are better HX choices and not just fire tube designs,I'd prefer a good aluminum HX to a Giannone.

hot_rod

I'd bet

there is a failed aluminum boiler for every failed stainless coil type Many installers neglect the fire side care and setup and routine maintenance. But many more ignore the fluid quality that can doom an aluminum block in a few years time.



Go west young man, and you will find many aluminum boiler failure stories, pallet loads of them. Something to do with the water out west that is un-frindly to aluminum alloy blocks. Not just the glycoled systems either that had low budget AL glycol in them.



Maybe the fracking chemicals in the water?

Jason_13

I wonder

What percentage, fact not opionions, of the worlds Stainless heat exchangers are made by Giannoni?

Kal Row

depends what your doing with it...

 the Giannoni is a really reliable and great "direct water heater", and has been handling chlorides in the water better than initially expected, but the pumping costs are just to high for hi-temp indirect or hi-temp space  heating applications - large Delta-T direct water heating or radiant pri/secondary is OK, (and don't even think about ECM pumps without a magnetic filter and water conditioner) - vertical firetube HXs are way way less expensive to pump through, but don't have the track record the Giannonies do, and dont forget the maintenance cost,  its supposed to be cleaned every year - i actually do 3-5yrs depending on the usage rate, and what kind of atmosphere  the boiler is breathing.

LAARS is rolling their own vertical firetube hoping to avoid the problems some have had with the polish one, and hoping  to cash in on the "made in the USA" factor, i know plenty people that would pay extra for that - Lochinvar has a different one for the CREST but that one is in a class all by itself. with nothing really to compare it to.

i wish someone also came up with a "USA" fan, am tired of the EBM PABST ones. they are too expensive and cant handle a drop of water, the worst thing with those blowers is not really their fault and would be a problem no matter who built it, that is, light construction derbies  gets into the fan when the place is under construction, but no one knows about it cause the fan still sounds the same, but it is actually  unbalanced and eating up its bearing, which will surely die after the warranty is up - those are the only failures I've had - water or junk in the blades - never had one just die

parts and repair cost is a big deal - and can quickly kill the fuel saving of a mod-con, i did a house with a three temp heating system - radiators, radiant in concrete, and radiant in an alumanized sub-floor with the parquet floor directly over the tubing with no intervening layer, and did it all from a cast iron boiler with a  standing pilot using a dual injection/mixing HBX CPU-1000 control - i gave the lady the choice with my usual saying which goes like this...

"a cast iron boiler with a standing pilot dumps one third its energy right up the chimney but will lose a thermocouple once in 30 yrs - add electronic ignition, and a good mid western style thunder storm, will  take it out in ten yrs, add a motorized draft hood and now your down to 7, add a draft fan and your down to 5, make it modulating condensing, and now your are married to it, a catholic marriage, you cant even get a divorce..."  she chose the cast iron with the standing pilot... duh!!!  

what sells modcons by us  is space mostly - people want a boiler room in a closet with no chimney - even the megamikva's boiler room had a space limit, every inch was counted - and talk about a pumping load... each 1.5mbh boiler has two modules and each needs a pump that can deliver 74gpm@35ft of head - using 3phase Wilo 1.5x70 water cooled pumps with Cerus PAS motor starters that senses/alarms over-current and under-current like  when an inlet filter gets clogged

hot_rod

8 years on this Giannoni HX

Installed this Lochinvar Knight 80 in 2005, one of the early Knights. I replace it this spring, lockout problems off and on, during the past winter, always when I was out of town of course. I replaced modules, but ended up breaking the circuit board on the inducer trying to blast some dryer lint dust off of it.



I decided to replace it with a Lochinvar Cadet with the DHW module.



I cut open the old HX today and was very surprised. It was opened and serviced every two years. A couple tablespoons of black crud was all I ever cleaned out. It was on LP. I used a combustion analyzer every time I serviced it and recorded the readings, but never re-adjusted the burner from day one.



The system has some non barrier PB , two zones of non barrier Heatway TwinTran, and some PAP in radiant ceiling. It ran 140F max on OD reset.



It was piped with a Caleffi HydroLink pumped with a 15-58 Grundfos on speed 2.



I cut a section from the HX tube to examine the inside. It had a thin film, which wiped off when it was still wet. Other then that the HX tube looked brand new inside, and just some normal combustion deposits on the outside.





I did put some Rhomar cleaner, then conditioner in it when it was installed in 2005. I would have to credit the Rhomar for the excellent condition inside the tubes.





I'm impressed and pleased with the performance and condition of this HX. Feeling bad now that I didn't spend a bit more time and $$ to keep it in service.



The new Cadet has the same HX, but in a composite case. I have no problem recommending the Lochinvar with this Giannoni HX, after seeing inside today.



Treat 'em right and they will return the favor.

Robert O'Brien

Spiral HX

There's another spiral HX as well

hot_rod

many styles

of tube HXers out there. Heck the Parker and Bryan "hairpin" tube boilers have been around a long time, maybe longer then the Giannonis.



A copper tube boiler is really not that much different from the spiral HX, just short tubes headered at the ends. Those too required plenty of flow to keep them happy and healthy. Many of the failures were caused by under pumping them.



It sounds like your concern with the Giannoni is the pump requirement? Power consumption of the pump?



As I mentioned earlier more and more ECM pumps are becoming available and the price will continue to drop considering the European markets are dictating higher pumping efficiencies. Already some of the OEM offerings for standard wet rotor pumps is being scaled back.



Maybe within the next 3-5 years all that will be offered is ECM technology on small circs? I'm not sure the large Euro manufacturers will want to make a non ECM pump just for the small US market. We are already limited in choices when you ask for 120V 60Hz



I think the Alphas hit the market in the $400.00 range. i see them out there in the $160.00 range now. As more players enter the market prices will no doubt continue to drop. Xylem, Armstrong, Wilo, Taco are all offering small high efficiency ECM circs, and another 5 or 6 Euro manufacturers are watching and waiting.





With pumping power down in the 40W neighborhood, for small and mid sized residential boilers, maybe the boiler flame will someday generate the electricity needed to power the pump and electronics. I've seen prototypes of that technology already.



Then again Nuke power is going to be too cheap to meter any day now, right. Electric boilers to replace oil and gas fired





http://www.power-eng.com/articles/2011/07/us-to-pay-100mn-in-nuclear-fuel-storage-settlement.html

SWEI

ECM boiler circs

Should really be controlled by the boiler in my book, and not run on a pressure algorithm.  Wonder why none of the internal boiler circs are setup this way?

CMadatMe

Agreed SWEI

The boiler control should vari the speed of the pump based on the modulation rate. Boiler should also give you the ability to select the delta-t you want to run. Heck I'd go as far as the boiler needs an on board zone control where you program in each zones flow rate. My boiler would only allow you to zone with zone valves and run a vari speed circ pump and it be a delta-t pump. Might as well get the entire system in sync with each other..

bob_46

Sounds like

Sounds like you guys are describing an overhead gravity system. Modulating water temperature , modulating flow rate and circulation powered by the flame in the boiler.

Kal Row

new Lochinvar boilers come with 0-10v pump output...

which can drive any pump on a VFD or a ECM pump with such an input - example Wilo Stratos with the "ext-off" module - i have used this - i even went as far as switching the boiler pump and "system" sensor between the the radiant zones manifold and the radiator zones manifold with a relay so that the boiler knows what to do with either demand - cause the boiler has three heating demand inputs with different reset curves for each, but but only one "system" sensor input and one 0-10v boiler pump output - so i had to get fancy with relays.

NYplumber

VDT

Good evening Kal,

I have had a fair share of playing with the knight boilers, usually in the form of servicing, never saw one with VDT. For design boiler work I haven't toyed with DT across the HX, but did ask a Lochinvar rep at a trade show recently how it was done and if a module was needed as I understand its application and would like to employ it. Needless to say I had three reps tearing the cover off a display unit but none knew the answer (display boiler was screwed shut to prevent internal show lighting wires from tearing). They took down my info, took my card and never called back, but did try to sell me on the Cadet. On my latest residential retrofit I have a Bumble Bee as the boiler plump (Knight WHN) so as not to experiment on the customers home with zero company support backing me up.

With this type of contractor to customer relationship, Viessmann may be getting my business. They're local, right here in RI, and rolling new boilers onto our shores.

Kal Row

attached is a snap of their board...

and where i hook up - see page 55 of the manual - and more in the service manual - they even have a min volts for pumps that need a minimum speed - if ur in the nyc area, then the boiler came from wallace-ennace - and u should ask for Jerry Katz out of the planfield LI office - who really knows the stuff and can help u with a total system solusion

SWEI

It's in the manual

From p.37 of the WH IOM:



Variable speed pumping to maintain a set differential temperature (ΔT) between two (2) sensors allows for the following:

-    Automatic adjustment of the pump's performance to match the low of the system or zone

-    Eliminate velocity noise in the zone valve systems

-    Conserve energy



Since ΔT is directly related to flow rate, the pump's speed continually adjusts to the required BTU per hour. In almost all applications the design of the system was based on being able to maintain a certain ΔT and figured by using the universal hydronics equation of BTU/hr = GPM x 500 x ΔT. Given that, any time there is a change to the heat load (i.e., warmer day or greater heat loss from a structure) then the GPM should change to match the required BTU/hr. This is achieved when the variable speed circulators automatically and continually adjust their GPM output (by varying speed) to match the required BTU/hr output of the system, no matter the changes in heat load, while always maintaining the designed ΔT between a supply and return sensor.



P.39 of the KBII and WB manuals also cover this, but in less detail.  Pump curves are different for those, of course.



I'm going to repeat myself:  Every mod/con boiler should really be doing this.

NYplumber

Thanks

Thanks for the lead Kal!



In your opinion, should I switch out the bumble bee to a vdt pump so that the boiler and pump "talk" to each other?

Kal Row

the boiler has to be in controll....

or u r just asking for a hi limit lockout - if ur pump doesn't provide the flow to match the boiler's current fire rate - u get a lockout, if the boiler is set to run of the "system" sensor but it's in the wrong place or getting the wrong flow - u get a lockout - dont second guess a smart boiler -



RULE TO REMEMBER

a sensor next to water thats not moving or not moving at the expected speed is lying

eg: a system sensor incorrectly placed on the boiler side of close T's, - the zone controller turns on system pump and calls for heat - but the boiler does nothing - since its sensor is still sitting in stationary hot water from prev run - and it "says" use the heat u already have, which u cant cause its hydro-Isolated by the close T's until the boiler puts on it's pump



the bumblebee is prob a bad fit for that job, if on the other hand u put it directly on a radiant manifold with zone valves it will do better than the grundfoss alpha - here's proof - on grundfos's new magna3's they provide an external return line temp sensor - just like the bumblebee - even though the grundfos autoAdapt does amazingly well most of the time



if u were using a bumblebee then the boiler is a small one and the expense of variable speed cant be justified - the return on investment is simply not there - use the recommended pump in the manual for the avg deltaT of your load - the failure rate of theses boilers is high enough - i cringe, cause i do both ends, the design and the service - and if i get to a boiler room with a non working bumblebee - trus u me, its getting replaced with a grundfoss ups26-99, stat!!!



i have told the taco people - the wilo people and the B&G people that they need a "26-99" killer - the dumbest thing is, that all B&G has to do is add a check to it's NRF-36 and they have it - wilo promised me they will - they already have the star21rfc - which comes in the box as a pump,a check, and 2 flanges that can be installed straight or rotated 90 - so they already have the grundfos ups15-58fc killer so i believe that will carry through on their 26-99 promise