Buderus Comparisions to Viessmann

Vito Learning

Yes, it CERTAINLY "learns" how the house reacts, BUT such learning has EVERYTHING to do with the heating curve which has EVERYTHING to do with the nature of the house.

Change the heating curve EXCEPT via the sun/moon dials and the Vitodens completely dumps its information and re-learns.

This is just ONE reason why curve changes (INTENTIONALLY USER-ADJUSTABLE BY THE WAY) should be made after AT LEAST two solar periods have expired.

I'll stand by that analogy when that "normal" mod-con uses ANY form of primary/secondary without variable primary flow.

Prove me wrong.

btw I wrote you politely, shortly and privately for the first time a few weeks ago. Aren't I even worth a F you?

subcooler

> Can you think of any other product that you own

> that if you run it 24/7 that you save money???

> Make a list for me I would like to read it.



"Can you think of any other product that you own that if you run it 24/7 that you save money??? Make a list for me I would like to read it."

Yes... a properly sized air conditioner in the summer runs far more efficiently than an oversized unit that is not running steady.

Why don't you give it a rest? You have your opinion and your rationale and you have expressed it well, but many simply don't accept that analogy.

Thanks...

Run 24-7 AND save Energy

That's EXACTLY what the Vitodens WANTS to do and it WILL achieve as long as the load is above minimum modulation and you don't confuse it with wall thermostats!

Unfortunately nobody has yet figured out how to achieve 100% modulation. Likely impossible when fuel is being burned.

I WILL though achieve such via solar integration. ALL ON TARGET AND EASY TO USE AND UNDERSTAND!!!!

American Over-Controlled Modulation

You got that right.

It's the ONLY way when you can't MODULATE BOILER OUTPUT TO STRUCTURE LOAD!

The "design" relationship between primary and secondary flow WON'T HAPPEN EXCEPT WHEN REALITY PASSES ACROSS!!!!

Ah, boys...

Time out... just a bit.

Both of you have incredible intelligence and passion for things BTU's.

I don't think anyone's passion is personal (benefit of the doubt goes to being playful, using the letter F for example).

Maybe we can take a short break, go to our rooms (me too!), come back and shake hands on common ground?

I will buy you both a virtual lunch, just not at Olive Garden or Taco Bell.

SubCooler: Your right

Currently anyone standing next to the nuke plant here would freeze to death after a while - definetely hazardous to their health. In the summer you might get sunburned and dehydrated.

Now if you want to check it out - please get on a jet and fly here. You will get more radiation exposure while flying here from most any place in the US from the radiation in the atmosphere where airplanes fly than I got this entire year from "my" nuke plant at work (and we know that very accurately). Oh, you will get more radiation exposuer when you fly back. Of couse, that is in additon to the normal 300 - 500 milirem that you get living where you do each year from natural sources.

Perry

most of my electronics...

I regularly go to sea with a couple million dollars of marine electronics for long periods. Computers, high- and low-frequency acoustic stuff, slow and fast sample rates (from Hz to MHz), you name it. They will run forever if you don't turn them off or crash them into the seafloor. They absolutely despise being cycled. Cycling leads to failure which leads to parts replacement and downtime. Both cost more money than running straight 24/7.

Although I agree with the inappropriateness of the auto analogy, I will say that my fifteen year-old truck is much happier and more efficient running for an hour straight than running in 6 ten minute stretches and being allowed to cool off significantly between cycles.

(Not a Viessmann owner.)

It's an odd clash Brad. jp brings out both the worst and the best of me...

Rob...

He gets the perfect answer and then he wants the top ten list! We need to stop feeding him.

You could try...

... a magnetic reed switch to capture the rotations. I wonder if the changing magnetic field (which the fob uses also) would not cause a reed switch to open and close also. These switches are found in alarm contacts (for windows), water meters, and other devices.

The Common Element

Each of the items you cite plus heating systems and clocks, run according to their need to run, which you pointed out. Some on-off just because that is what they do.

I think we agree but I am not sure I see the point you are trying to make besides the obvious. Am I missing something?

Never mind- I withdraw the question.

Best,

Brad

The real answer is something along this line:

First: What mechanical/electric items need to run 24/7: Only the clock.

Second: What mechanical/electrical items could run 24/7 if it was properly sized and modulated (may be season dependent):

Heating, Cooling, Humidification control, other air handling equipment, refrigerator, freezer, (and perhaps the sump pump in the right area).

Third: What items are only used for a limited time each day: Lighting, TV, radio, garbage disposal, washing machine, and dryer.

Now look at the second list and ask the following question: Knowing that the reliability of the equipment would increase if it was run 24/7 - which items on that list is it economical to build the various sized equipment needed on the market and the control system that would maximize efficiency of the equipment (which of those items have a potentially high enough payback to pay for the additional design and controls cost)?

I submit my simple analysis indicates Heating and Cooling (or other air conditioning processes such as humidification control and filtering).

I would not spend $500 - $1000 extra for a variable capacity refrigeration unit and controls for my home refrigerator, freezer, or for a variable capacity sump pump.

No the industry has not missed the boat as you find industrial refrigeration and freezer systems that do modulate and do run 24/7. Commercial and industrial air conditioning and air distribution systems run 24/7. In areas that need large constant flow sump pumps you find pumps that run 24/7 (often with variable speed controllers).

What is happening is that the variable load equipment and controls have now gotten cheap enough for it to be installed on home heating equipment where there is a good payback. Now just like other high end technologies you see it on the equipment that is on the high end of the market first. My guess is that in a decade or so that all mod/cons will come standard with the advanced controls typical of the Vitodens 200.

If you look at commercial and industrial processes - you will find many things that are best run 24/7 for many reasons. Some things are so efficient when run 24/7 that companies pay time and a half for Saturday and double time for Sunday labor (ie: these processes will typically run either 5 - 5.5 months and shut down for a 2 week maintenance, or 11 to 11.5 months and shut down for annual maintenance, or even have 18 month or 2 year shutdown cycles.

Unit 2 of my nuke plant just completed an approximate 18 months online, and then shut down for a 5 week maintenance and refueling outage. Unit 1 has been online for about a year now (we had a trip a little over a year ago due to a failed pump) and we expect to run to April when we will shut it down for maintenance and refueling (another 5 week outage).

Before you claim power plants as an exception I encourage you to look at other industries like paper mills, oil refineries, chemical industries, metal production, etc. The efficiencies can be so great with 24/7 operation of many processes that wages paid to operate the equipment do not matter much.

Industry is missing nothing - It is just now the technology to gain those efficiencies is being put into home heating sized boilers. You don't yet see it on other equipment as no one sees the payback for it yet. But I suspect that home A/C will follow next. Heating and A/C are two areas with high potential cost savings and great paybacks by use of this type of equipment.

Perry

brad, you're BAD!!!!

olive garden for spinach salad, taco bell for some tacos with green onions and lettus, and lets stop at jack-in-the-box for some hamburgers? then settle down with some hemlock tea to end the evening......

I like dry humor!!!!

Flaw in Logic

Could not have said it better myself. Most all heating equipment need other support systems to run. Using power to sustain the 24/7 flame???

Based on everything I've read here

I have come to the conclusion that Viessmann people are narcissist and I would never purchase that boiler. Especially since it has to be installed by the elitist and snobby contractors that tout it's greatness. Efficiency is efficiency, boilers last a long time and all the manufacturers stand behind their products. When you are done patting each other on your upper echelon behinds, please notice that 2 Burnham CHT Boilers will be going in my home. Thanks, Jules

But not for the reason you think

You are correct that nuclear plants want to stay as close to 100% operation as they can. This has nothing to do with thermal effeciency - it really has to do with maximizing the ecomonics of the plant. The fuel is already paid for; and nuke plants have very large and very well paid staffs. The more electricity you can generate between the scheduled outages the more economical the plant is. However, given a choice between operating at reduced load and going into a shutdown and startup we will always chose to operate at reduced load. This may occur more often than people realize for various reasons (not always plant related).

Fossil fired power plants on the other hand have a very large cost directly associated with how much electricity they produce - the cost of the fuel. They cycle up and down a lot. Most coal fired, oil fired, and gas fired baseload plants cycle between 20 or 25% load and a higher load (80 - 100% capacity) during the day. Middle of the night is light load, there is a morning peak when people get up and get ready for work, there is a cooling peak in the summer that starts about 11:00 and often runs to 4 or 5 in the afternoon, and an evening peak between 6 and 8 when people get home and do supper, with the load trailing off to minimum usually by midnight.

Many of these baseload fossil fired plants also operate for 6, 12, and even 18 months before shutting down for maintenance. They also cycle almost every day between a minimal generation and what is needed for the peak.

One of the reasons the Nuke plants are usualy held at 100% is that they are almost always the cheapest electricity on the grid unless you live in an area with substaintial hydro generation. I note that this power cost includes the cost for disposal of the Spent Fuel, decommisioning the plant, and even an insurance policy to cover the cost of a disaster (many multi-billions of dollars are sitting there and available). All of these cost have been built into the nuclear plant electrical rates for decades. The plants have so far paid the US government about twice what Yuka mountain is expected to cost to open and operate to dispose of all existing power plant spent fuel (or any other proposed long term plan for spent fuel) so far - and the US government gets more money each year.

So if you are going to look at power plants - you need to look at the fossil fired power plants as an example - and the most directly related example. They run for months or even more than a year - and cycle all the time based on load. Just so you know: I spent most of my power plant career in fossil power plants - and only fairly recently (6 years ago) started working in the nuke side of the business.

Perry

Really?

Not a challenge but I find it hard to believe that centrifugals are only 1%.

You *did* mention centrifugals but I read it as "centrifugals are better staged", (leaving out the "but" and a comma or two, -my bad).

Still, at least in my world, centrifugals account for at least 30% of the projects we do. At about 150 tons and with the turbocors down to 60 or 75 tons, we see the number of centrifugals going up!

Jules...

That sounds pretty harsh. You really need to keep in mind that it is a lot harder to choose a contractor than a boiler brand. The boiler is one of literally hundreds of big and small decisions that need to be made on your install.

Everyone puts a lot of thought into these things and everyone has their own reasons for their particular preferences, both homeowners and contractors. Only the manufacturers and wholesalers have to narrow their focus.

Have you actually met any of the Viessmann contractors in your area? The two that came to my home were far from elitist, but they were both very professional.