A Sneak Preview (ME)

Mark Eatherton1

Finally, Buderus and their wholly owned subsidiary Nefit are getting ready to introduce their version of a wall hung condensing boiler to the American market. In the usual Buderus way, they want to make sure that all bugs are addressed prior to releasing the product here in the US.

They needed a high altitude test plot to try their wares, and Lou V offered to let me have one. I already own a nice condensing boiler, but my partner was in need of one, so we had our guys install it in Toms house.

Nefit sent Alex Heino and Marcel van Waveren over from Holland to complete the commissioning of these beauties. In addition to Tom, Dennis Bellanti, my 70 MPH conversationist, is also getting a unit installed at his home. Their intent is to see how the units handle our derated gas (830 btu/cu ft in Denver). There will be one other installed up in the Dillon area on the Western slope. The units will be monitored via cable modem.

I must say, it is a FINE piece of engineering. They have an Infrared communication adapter that plugs into the control, and then uses a Palm style PDA to upload and down load information from the onboard computer. It's quite similar to the software that comes in the Munchkin as far as the parameters it can watch and see.

The HX is an aluminum alloy. The Nefit company has over 15,000 of these units in operation in Europe.

At present, it is a fixed set point system with a 3:1 turn down ratio. They have a unit in Europe that will allow outdoor reset with indoor influence. They will be "Americanizing" this unit so that it can be offered on the American model.

They took the boiler completely apart and put it back together again in under 5 minutes... It is MEANT to be worked on.

Buderus' goal is to have these units fully tested, approved and ready to roll by next years heating season.

No word on price yet, but I suspect it will fall someplace between the Vie$$mann and the Munchkin.

The unit shown is a 102,000 btuH unit (30 KW) and they will also have a 50 KW (170,000 btuH) unit available.

Eventually, their units will be equipped with a variable speed circulator on the boiler side, along with all the bells and whistles us American hydronic contractors so richly deserve!

Between these two Dutch boys, and Eric Legend of Buderus USA, it was an interesting morning to say the least.

Now my partner will get to see and feel what a good condensing heat source is all about.

I promised Eric that I would remind you that the units will NOT be commercially available until next Fall, so hold your horses and keep your ears to the ground. It's a comin'!

Enjoy!

ME

Unknown

Mark, what is the

screwdriver in the vent for. I notice that it exhausts to outdoors but no air intake. Does it get air from outdoors or from indoors?

Whose gas valve is that on the unit? Sorry for all the questions but I am fascinated by all this new stuff. I may have looked to quickly at the pictures but does it have a pressure switch?

I have a lot more questions but will wait for others to comment and follow the post.

Mark Hunt

Timmie


that is a concentric vent termination.

Exhausts out the middle, and draws combustion air in the back.

Mark H

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Mark Eatherton1

Tim...

Not sure where you see a screwdriver in the vent.. There's an old style Testo combustion analyzer in the CPVC vent.

It pulls its combusion air in from the back side of the exhaust vent. Its a concentric vent kit going thru the wall. The unit is truly sealed combustion. I don't remember seeing anything in the way of a pressure switch, and not sure whose gas valve it uses. Probably a Euro Honeywell:-)

The onboard PC monitors fan speed in RPM, so it may not need a pressure switch. It uses a pressure differential reading to increase and or decrease gas flow like all it's cousins. If you block the vent with your hand, the burner rolls back to nothing.

I can see I'm probably going to have to get Eric to come on here and answer some of the questions I can't answer.

Why is it that you remember all the questions you wanted to as AFTER the smart folks have left the job...:-) Like, "How long do you expect this appliance to last?"

ME

hr

Looks MZ ish

in design What kind of readings from the Testo? Nice looking control module, beam me up Tommy.

hot rod

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Mark Eatherton1

94%

if you believe the analyzer... It was running at 98 ppm CO and around 9.4% Co2.

Jim Davis taught me to ignore the combustion efficiency output readings from the combustion analyzers. Theres a 100 ways to hit the same number. Which one you gonna believe.

I thought MZ too when I first saw it. Isn't MZ owned by Bosch? Buderus and Nefit are...

ME

mph

Buderus boiler

I love to see Viessmann get some direct competition. It can only help to bring the prices down. From the pics this looks like a well-made unit. Is it as quiet as the Vitodens?

Jeff

Mark Eatherton1

Virtually silent...

You have to look at the lights to see if it's running...


ME

Paul Pollets

Question, Mark

I presume the unit does run off an outdoor reset computer? Does the gas valve modulate or only the exhaust fan?

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hr

I often wonder

that finned tubes in a condensor are not all that different than finned tubes in a copper tube boiler. They see the same byproducts of combustion?

What,if any, cleaning and maintenance instructions.

Any criteria for fill water? Glycol types and amounts? Aluminum is a VERY ph sensitive material. I wonder that certain alloys are less sensitive.

HX warranty? Certified installers needed.

Too many questions too soon ?

hot rod

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Mark Eatherton1

Paul,

In one of the photos, you can see Marcel in front of the exisitng Buderus cast iron boiler. It has a Logomatic 2107 controlling it, as well as a mix card for his RFH system. At present, the Nefit is only modulating around a fixed set point (160 degrees F), but can eventually be expanded to do a floating set point based on reset, and the boiler will modulate around the moving set point.

Flame modulation is accomplished by increasing the negative pressuer to the gas valve by varying the fan RPM, and the pressure across the venturi. Hence, if you block the flue, the burner shuts down.

ME

Mark Eatherton1

Good questions...

I asked some of them. Maintenance in Europe is doneonce every two years. It entails removing the burner, and the condensate colection module, spraying some sort of oil based cleaner on the HX, NOT rinsing, but reassembling and firing up. He said the exhaust plume smokes for a few minutes immediatley after this process.

Being an aluminum block boiler it IS sensitive to high pH, and should be maintained around neutral (7.6).

We'll have to ask Eric the glycol, warranty and certified installer questions...

Thanks for asking!

ME

Unknown

Thanks Mark, I

was not sure if it was or if it came in from another location.

Unknown

I am not familar

with that Testo tester, it looked like a possible adjuster in the flue to control exhaust gas velocity. I had worked with such a device a few years back and thought it might be another one. It never worked very well.

Ted_9

Buderus

So... the anticipated release is in Fall 2004 or 2005?

Mark Eatherton1

2004 (NM)

ScottMP

Mark

You said it is sealed combustion unit. I notice the intake is located next to the exhaust like in the munchkin. Is the cabnet sealed or is a "open" cabnet like the munchkin ?

The unit looks great. I'll have to talk to my rep and get some info also.

Thanks for the photos

Scott

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S Ebels

Sweet!

A tuned velocity stack on the air intake for the burner! High performance all the way.

Can't wait to get my hands on one of those to see what it'll do.

Kal Row

Kal Row

i hope you are right about not believing the test equip

because those numbers don’t seem to good to me - the CO is way to high for a modern high eff setup, usually high CO is not enough air for the mixture - and since the combustion fan assures adequate flow - it must excessively rich mixture for the selected draft fan speed – ( I will give them the benefit of the doubt – that they do modulate the fan speed with the fuel valve)

so far I haven’t seen anything here, that the Weil-McLain Ultra doesn’t do better, probably cheaper, definitely here and now, – and they are getting a 98% AFUE in a radiant setup with a 110° supply and 90° return – so I am waiting to be impressed

Kal Row

dan: we need a way to edit out double-clicked msgs

Mark Eatherton1

Kal

The reason I said that is because my own little condensing power plant was showing 94% combustion efficiency and I KNOW for a FACT that it was doing 98 to 99 % thermally efficiency at that very state in time.

I'd bet you a box of Crispy Creams that the Wiley Mac don't show numbers any higher than that using the same analyzer.

I've only seen one combustion analyzer that showed really high numbers. It was the old suit case sized analyzer from Bacharach, and it was on a Munchkin 140 that had 40 degree F water running straight through it. It showed 99.9% for the longest time, and then for just a few seconds popped up to 100%. If I had not had a student witnessing this over my shoulder, I would not have believed it either.

My Testo had just been factory calibrated when it was showing the 94% versus the 99% I was seeing from my mass flow meters.

The Nefit boiler shows high CO on high fire. When it drops to low fire, which is where it will most likely spend most of its life, the numbers drop to reasonable parameters. Trust me, these boys know EXACTLY what they're doing. They have to conform to the Kioto Reforms laws, which is better than any of us do...

ME

Mark Eatherton1

It has gaskets on the door.

it is truly a sealed combustion unit. They have a full concentric venting kit in Europe for recovering waste heat.

ME

Paul Pollets

maybe

maybe competion on price, but not in features or benefits. The Vitodens comes complete with outdoor reset, modulating gas valve, modulating burner, modulating circulation and modulating exhaust. Not to mention 316TI stainless construction and a single combination vent. I've learned that there are many differences between wall hung or condensing boilers. All features and benefits have a cost, and should be factored into any "comparison". Let's see how this one performs in the field. Buderus makes good equipment. I'm sure their wall-hung will make a dent in the marketplace.

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Kal Row

i dont like high Co anytime

and in my unhumble opinion, they are all producing way too much CO - (even your kitchen range is producing too much CO), though a pretty good one is the new veissmann, with the dome shaped metal grid flame retention head, that gets complete low temp slow burn and even recovers the flame's radiant energy too, - but who wants to pay for it!!!

about analyzers, i think only, those expensive 4gas units that certified automotive inspection stations are using, are any good,

i would give up gas eff, to get rid of CO, ie lean the mixture out so much, that not all the parcels of fuel+air+heat connect and you are left with unburned fuel at the end, - but it has to be done right so that the lean mixture, doesn’t give you cold spots - which again results in CO, since in a cold spot, the mixture (relatively speaking) is locally rich

this is not going to change until our government mandates it and the combustion becomes computer controlled with an air-flow, barometric, and temp sensors going in, and a temp, and o2 going out, just like you car, us signing the Kioto protocols wont do it, but a couple of more gas hikes like the ones from this winter WILL!!!