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This is BETTER Than My First Erector Set

New Vitodens just starting to learn how to drive a big old gravity conversion system with TRVs and radiant bath floors. Only the built-in circulator and no low-loss header.

In the last hour my house was calculated to loose 22,000 BTUs. This does NOT include any losses for the basement that averages 50% above grade.

Checked meter. I used 24 cubic feet of gas which is approximately 24,000 BTU. Not using Vitodens for domestic hot water and turned water heater way down--but it does still have that pilot...

At 94% efficiency that means I had 22,560 BTUs on the "good" side of the equation compared to an expected loss of 22,000.

Believe the Vitodens fired continuously during the period! NO CYCLING at a temp a touch below the old warm-weather shutdown point! Noticed that the actual supply temp rose a bit higher than setpoint--102° setpoint vs 109° near the end of the hour. Burner has now cycled off. Not sure when or for how long.

Flue temp peaked at 104.9° during the period with an average of about 99°.

Should I WASTE some gas by switching over to the old W/M for an hour? Conditions seem ideal for the worst-case for that boiler. Haven't re-lit the pilot after installing the Vitodens. Other than that I just have to close two valves, open two others and flip two switches...

Sure looks good for that simplified calculation I made showing that my gas use would drop by a touch over 50%.


  • joel_19
    joel_19 Member Posts: 931

    Just like the Sox and the Pats you just gotta believe in the Viessmann way. Congrats my son you have seen the light.

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  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    After About 40 Hours of Operation

    Outside temp has varied from 50.2° to 55.8°. Warmest through last night, now falling and currently 50.4°.

    Current boiler setpoint is 100°. Burner fired for at least the 30 minutes I was just downstairs/outside. Actual supply temp nailed at 100°.

    Return temperature is steady at 74.9°.

    Checked my temperature/flow calculations and setpoint is supposed to be 107° right now with a return temp of 71° and 36° delta-t.

    Plugged the 100° supply number into the table and guess what return temp was calculated? 75°!! Yet more confirmation that my reverse engineered heat loss calculation is accurate and that those spreadsheets that calculate flow and return temp based on surface temp are accurate as well!

    Will add another two degrees Celcius of upward parallel shift to the curve as the bath floors (and baths) are a bit cooler than expected. Reset ratio is 0.8--typically the lowest expected with standing iron and highest expected with radiant floor.
  • Constantin
    Constantin Member Posts: 3,796
    Isn't it nice when...

    ...countless hours of "engineering", thinking, etc. result in a fully functional system?

    Doing cost-models for the DoE can be pretty dry. However, when you walk into a plant and see that the models' predictions to be accurate within 5-10% WRT the number of workers, machinery, etc., you feel pretty good about yourself.

    Or, when a client challenges you on the number of $$$ turret-punching machines they'll need for their factory and you simply reply... "you'll see". Fast forward a couple of months and the shop steward comes back with the same number, based on actual, not projected, cycle times per part.

    I guess computers are useful for something, after all. ;-) Congrats on a fully-functional, happy, and cost-efficient heating system.
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    Not That I Didn't Believe, But...

    ...this is the Show-Me State afer all :0

    Here's my condensate collection/measurement/neutralization unit. Thing in top is a rainfall sensor. Calibration instructions allow me to compute actual volume based on inches of "rain". Solar powered, so will put a little night light on a timer to keep it charged. Not the ultra-expensive heated type that can be used outside in the winter so it has to come in anyway.

    2nd shot shows the inside. Vast majority of water will drop through the PVC pipes and exit through holes in the bottom. Will put in 8" or so of limestone for the neutralization. The plywood will probably rot in a year or two, but by then I'll have my data and will just run the condensate directly into one of the pipes.

  • Mark Eatherton1
    Mark Eatherton1 Member Posts: 2,542
    What are you doing with the condensation???

    Mike, I know you're in an older home with cast iron drains. Make sure you do something to neutralize the condensate prior to discharging into the sanitary sewer or you will be replacing them. It'll take a while, but it will eventually fail. (voice of experience talking here...)



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  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    Not that I Didn't Believe, But...

    ...this is the Show-Me State :0

    Photo shows my condensate measurment/collection/neutralization unit. Thing on top is a rainfall sensor. Calibration instructions give the ability to convert inches of rain into volume of water. Solar powered so will put a night light on timer nearby to keep charged.

    2nd photo shows inside. There's a tipping mechanism inside the sensor and water alternates from side to side. Vast majority will go down the PVC pipes and exit through holes in bottom. Will add about 8" of limestone for neutralization. Plywood will probably rot in a year or two, but by then will have my data and can just run the condensate directly into one of the pipes.
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    Bees Knees!

    It really is cool that predictions seem dead-on accurate! ONLY reason that was possible given my limited abilities is the modulating nature of the system. You can actually solve for a constant in constantly changing world!

    Hard to stay out of the basement right now! Will be glad when the rest of my sensors arrive so I can write a program to graph the data over time. Supplied software with the computer interface for the datalogging weather system is a bit lacking but fortunately it gives access to the raw info.

    For any skeptics out there, this boiler DOES learn. For a while yesterday afternoon it was firing in very short intervals. I believe it's learning the ideal time to go into WWSD. Since it can't "simmer" I believe it's learning just how much to allow the system temperature to drop in warmer weather before starting a nice, long firing time at minimum output.
  • Constantin
    Constantin Member Posts: 3,796
    Looks great...

    ... and easy to clean. There is enough volume in the box to allow for very good neutralization, no matter what media you use. Should be cheaper to maintain than the OEM pellet-style system...
  • Constantin
    Constantin Member Posts: 3,796
    I'd be interested...

    ... to hear about your system once it is running. Maybe I'll buy that software too ;-)
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928

    We're on limestone here so went to quarry and got a couple 5-gallon buckets of ½" crushed, washed limestone. Should work fine.

    Call me a tightwad, but over $200 for the Viessmann neutralization unit was a bit steep and it seemed to require their special pellets at $40 or so per pop. Less than $20 for the materials and $0.00 for the stone. Beside cost don't think I could have measured the condensate going into their neutralizer ;)

    My basement will NEVER be pretty as I have a thing against finished basements--particularly in old homes. They just hide problems where you can't see or fix them until they're VERY expensive.
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928

    You mean the datalogging system? It's from LaCrosse Technology. System WS-2010. Really a weather station, but there are many accessories and you can have up to 16 sensors. It's the low-end "professional" model. A bit pricey but search the web CAREFULLY! Found a HUGE variance in price when I bought last year.

    Only samples data every 10 minutes, but that should be fine for use in a system that fires nearly continuously.

    Like all wireless devices I've used, their transmission ranges are HIGHLY idealized. The solar feature on the main outside temp/humidity sensor, rain gauge and anemometer are convenient, but finicky. Other sensors are battery operated--farthest ones away in the house are starting to have quite a few "misses" so even the good lithium batteries have a useful life of around a year or so.

    Solar feature on outside temp sensor is really kind of stupid in my mind as you have to ensure it gets some direct sunlight and it tends to overshoot by a few degrees when getting sun.

    Computer interface unit (serial) is battery powered as well. About a 6 month life. Connecting cable is SHORT--about 3' and cannot be extended.
  • Constantin
    Constantin Member Posts: 3,796

    So, far, I'm not sure this one is for me... I live a simple life on the Mac side of things, and my last Mac with a built-in serial port is, oh, 12 years old. Granted, I may be able to use a Keyspan adapter, but the software end starts getting hazy, at best.

    I'll go a hunting for something USB-based, hopefully with Mac support. The 2010 looks like a very capable unit though...
  • Constantin
    Constantin Member Posts: 3,796

    That is a battle I will be facing with my GC... I think.

    I expect he wants the home to be totally finished when he's done. I'm of the mind to keep the basement ceilings unfinished until the renovated home is a year old. Then, repairing an issue is a lot simpler... We'll see. He may change my mind yet, we're both flexible.
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928

    It's termites that bother me more than anything. Basement was finished at puchase as house was 8 apartments. While they weren't still living, termites had begun by eating the furring strips on the brick foundation. Framing is cypress and termites don't care much for it, but they WILL attack if there for long enough! For a 1903 brick basement (triple wythe) it's extremely dry, but in very wet periods a bit of visible water will come through at the wall/floor joint. Besides that, there is ALWAYS vapor passing through those old bricks and I'm NOT going to trap it inside of some wall construction!

    In a couple areas the interior brick had spalled slightly--not sure what happened but it could have been from window leaks. These were also the areas where the furring strips were almost completely eaten. Dug inspection holes to see the outside in those areas and the brick and mortar were in perfect condition.

    At least you have a new concrete foundation...
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928

    Bet your new foundation give good ceiling height in the basement. Grid ceilings aren't exactly beautiful, but they are practical for access.
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    Very Rainy Night

    27.63 inches!

    Translates to about a quart of water (.246 gallons).

    Seems a bit low. Hope it's not overloading the sensor.

  • Constantin
    Constantin Member Posts: 3,796
    A foundation built for the ages...

    ... or so I hope! We had huge issues with termites eating out the rear of the house, even though MA isn't exactly known as a termite haven. That part of the house is gone, now rebuilt. Between the waterproofing (Rub-R-Wall), the foundation drainage, and the much better downspout water management, I hope we'll have peace now.

    Instead of 7'1", we now have 8.5' of height... makes a huge difference, particularly now that we don't have ductwork for the whole house traversing the space...
  • S Ebels
    S Ebels Member Posts: 2,322
    Now that you mentioned sensors...............

    Remember the install everyone pitched in and donated equipment, $$$$ and pieces parts? The one for Sandy?

    Anyway, the OD sensor was mounted high on the house right under the soffit. She called the other day, it was about 42* outside and said she had no heat. I went over to find out what the problem was and FORSOOTH AND BEGORRAH!!!!! the outdoor air temp on the 2107 read 88*. I said to myself "This is not right!!??" and began to investigate further. During a short chat with Sandy it was divulged that she had decided to get rid of the cobwebs and other various creepy crawlers making their homes on the exterior of her domecile. She powwweeerrrrwashed the exterior of the house to rid it of the unwanted critters! Now, number one, I give the little gal credit. She's only about 5'2" and chases after 4 "livet kinder" as gramps used to say in Dutch. I asked her how she reached the second story eave and she said "I got right up there on a ladder while the kids held it." I knew then and there that I would find the suspected problem in the outdoor sensor itself. Turned out that the mud wasps had effectively sealed off most of the sensor casing causing it to become submerged in it's own shell. This, as you would expect, somewhat reduced the resistance of the thermistor enclosed therein. Within moments of a minor drain and clean job the temp on the 2107 read a nice balmy 42* just like it should.

    The things you don't run into................
  • Constantin
    Constantin Member Posts: 3,796
    ... am going to go after a different system

    ... but thanks for the inspiration! There is a Mac based system which is pretty reasonable and usually geared towards the EDU market.

    The vitotronic will give me a good indication about fuel usage, firing time, etc. Yet, I'm thinking of capturing where the energy is going. Here is one way I can think of how to do it:

    1) Capture the on-off of the thermostat in each zone to see when and for how long they call for heat.

    2) Put thermostats on the system returns and the supply manifold, measure ΔT across same. The supply manifold has only one temp, so that's easy. An additional 6 manifolds are fed by 6 pumps... so 7 temp sensors total.

    3) Adjust the speed of the circulators such that every zone in the house has the same duty cycle and ΔT such that one reset curve for the house becomes possible.

    Am I on the right track? The supply manifold is fed by a 4-way valve. All-radiant floor heating. Vitola, i.e. shock- and condensation-proof boiler. Any thoughts?
  • jerry scharf_2
    jerry scharf_2 Member Posts: 414
    temperature datalogging

    If it's a fixed location and you have a computer to collect the daat, check out the 1-wire sensors at www.maxim-ic.com. There are 12 and 16 bit thermister probe available that can just be pigtailed with wire and and strapped to something to read. Cover it with some insulation to even out the thermal coupling if needed and voila.

    The computer hookup costs about 50 bucks, and the probes are under $5 each! There are free software apps on the net that will read and collect the data from these. There are other parts that can count pulses, take analog inputs and the like, but these require more work than the simple heat sensors.

This discussion has been closed.