Exhaust question for newly installed Biasi B10 Boiler

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Old 09-10-08, 11:51 AM
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Exhaust question for newly installed Biasi B10 Boiler

Hi! just got a new Biasi B10-4 boiler installed and I have a noise problem. My very old Weil-McLain was loud and rough sounding. This Biasi is very quiet...sort of. The "enclosed" Riello burner is almost silent. The boiler itself makes very little noise. However the exhaust noise if not loud, is very pronounced. It "Roars".....very smoothly but it makes enough noise to bother me. My tech, who did a great job in the install was a tad upset when I complained about the noise. He doesn't hear what I hear...In any event I asked him if the metal ductwork (exhaust) could be wrapped and he said: sure! but didn't want to talk to me about it after he had just finished the install. I think I hurt his feelings...Whatever..! Some one told me to make sure that the exhaust pipe was the correct diameter...it is, 6" per the specs from Biasi. So, my question is: Can I wrap the pipe with some kind (High Heat) sound insulation wrap? and besides reducing the sound level am I doing any potential damage to anything? Thanks, Bill
 
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Old 09-10-08, 04:07 PM
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The installer didn't cut any corners and use that 30 gauge ductwork they sell at big box stores, did he ?

It should be at least 26 gauge material.

I don't know of anything to wrap the pipe with, but I should think that the double wall vent pipe ( the kind that has two concentric pipes with air in between, not the insulated manufactured chimney stuff) would cut the noise dramatically.

Is there a barometric damper installed on the flue pipe ? If so, you might also investigate an 'elephant trunk' setup for that. Instead of the damper plugging directly into the tee in the pipe, you would come off with a 90 elbow, pointing down, and another 90 pointing horizontally again, and the damper on the end of that. This could cut down the noise from the damper area somewhat.

Can you post some pics of the install by setting up a free account at www.photobucket.com , uploading the pics there and providing a link here ? Maybe we'll see something to give more ideas ...
 
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Old 09-10-08, 04:23 PM
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Biasi noise problem...

Thanks NJ! Not sure of the guage?? I will download a couple of pics on thurs. I like the idea of the double wall design. In the meantime I have a circulator question that you or someone can answer. I have 3 Grundfos circulators for 3 zones. Each circulator has its own adjustable low/med/high/setting or anything in between. Someone told me that if you have a zone with a long distance of baseboard or just hard to heat rooms that the high setting is better..stronger faster flow. Any thoughts? Is there any advantage to a particular flow setting? Thanks, Bill
 
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Old 09-10-08, 07:51 PM
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Biasi noise problem..Photos to show install

http://i397.photobucket.com/albums/p...IMG_2384-1.jpg
http://i397.photobucket.com/albums/p...IMG_2387-1.jpg
http://i397.photobucket.com/albums/p...9/IMG_2386.jpg
http://i397.photobucket.com/albums/p...IMG_2388-1.jpg
****NJ Trooper, check these out! There is water on the floor because the zones had just been purged and someone got sloppy with the hose. Found a sticker on the main section of pipe, it "is" 26 guage, so I would appreciate ways to quiet the noise. Thanks, Bill
 
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Old 09-11-08, 04:03 PM
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Originally Posted by bostonfan49 View Post
... if you have a zone with a long distance of baseboard or just hard to heat rooms that the high setting is better..stronger faster flow. Any thoughts? Is there any advantage to a particular flow setting?
What sounds like an easy question to answer actually is sorta complicated ... (ain't that always the way ?)

What you shoot for when you size a circulator is proper flow in the circuit, which for a 3/4" pipe should be not much more than 4 gallons per minute, and not too much less than 2 GPM.

Too much flow creates noise problems... you will hear the water running in the pipes. It can also cause erosion of the pipes from the inside.

Too little flow, and you can have air trapped in the pipes that simply won't move. You also may not get enough heat output from the emitters at the end of the loop.

The amount of flow that a given circ will produce is determined by the amount of resistance to flow in the loop, called HEAD.

There are PUMP CURVES that designers use to determine the pump size and/or speed that they need to give the flow they want in a given situation.

Designers usually shoot for a supply to return temperature difference in the neighborhood of 20F. This is because with a 20 difference, the 'math' becomes easy to do in the head. For every GPM of flow, you can move 10K BTU of heat.

So, let's say that you have 4 GPM flow. That means that you can extract 40,000 BTU from that water and the return water will be 20F cooler than it entered the loop.

Let's also say that typical fintube baseboard will output appx 600 BTU per foot of element (at an average 180F water temp). If you divide the 40,000 BTU by 600, you get appx 66 feet.

So, if you have loops of that length, you would set your circs for 4 GPM, and determine that flow by the difference in temp between the supply and return, shooting for a 20* diff (or DELTA T).

Remember that these are the ideals... the system will work fine over a range ... you might have a 30 DT (delta T) and no problem ... or a 10 DT... still no problem. Your loops might be 80 feet ... or 40 feet ...

OK, now that I've said all that...

Where do you set the speed on YOUR circs ?

Good question.

For starters, how long are the loops ?

If they are much longer than 66 feet, your DT will be higher than 20 ... rooms at the END of the loop MAY be a bit cooler than rooms at the beginning, because the water reaching them will have cooled on it's way around the loop. But, it still may not require the high speed on the pump.

Start out on low speed. Save some electricity. If you find that rooms on the end of the loops are uncomfortable, then kick it up a notch to medium.

Chances are that you won't need the high speed.
 
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Old 09-11-08, 04:12 PM
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As for the noise... you could try replacing that straight section with the double wall stuff and see if it helps.

24ga is also available and may help too ... but it's harder to work with ...

You should be able to find that stuff at wood stove dealers.
 
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Old 09-11-08, 04:18 PM
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Biasi noise problem..Photos to show install

Thanks NJ Trooper! Where would I find the double wall pipe? Thanks, Bill
 
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Old 09-11-08, 05:54 PM
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Is it possible, there is a vibration in the blower causing the noise? Also, are all the joint sealed with high temp caulking if needed?
 
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Old 09-11-08, 06:05 PM
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Sorry, I did not read through thoroughly before opening adding my 2 cents. I did not realize boiler was oil.

I see nothing wrong with the installation of the boiler. looks good to me except...

I do not see a draft regulator installed in the smokepipe. I wonder if that is a cause towards the noise problem. Even if that does not help with the noise, A Draft Regulator is commonly required to adjust the draft so the burner runs properly.
 
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Old 09-11-08, 06:11 PM
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Biasi noise problem..Photos to show install

...thanks Plumbingods! Yeah, I'll have to ask the installer why there is no draft inducer????? I don't know if it would do anything...Bill
 
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Old 09-11-08, 06:25 PM
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The Biasi manual does say that in some cases a barometric damper isn't required ... (Bill, a draft inducer is a different aminal from a barometric damper by the way... an inducer is typically a powered fan device intended to increase draft, while the damper is intended to prevent too much draft by opening as required when the draft is too high)

They say that since the boiler is pressure fired, it may not be required for some one and two story homes... I guess it depends on the installer making measurements and determining whether or not one is needed. I hope he did so.

Here's a link to the I&O manual for some light reading...

http://www.qhtinc.com/pdf/B10-Manual-REV-G.pdf

Page 15 has info on exhaust venting.
 
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Old 09-11-08, 06:30 PM
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Originally Posted by bostonfan49 View Post
Thanks NJ Trooper! Where would I find the double wall pipe? Thanks, Bill
Try the wood stove stores in your area.
 
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Old 09-11-08, 06:34 PM
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I did not know that it may not be required.
Did the installed use ant combustion analysis testing equipment when starting this boiler? If so what are the readings?

Biasi is the same as Pensotti. I don't remember if they needed draft regulators.

That was like when I found out you could pressure fire Ultimate boilers. I showed up at a customers house and saw the smoke pipe going right out the wall with no venter attached. I immediately informed the customer something was wrong. Boy, did I feel like a fool when "she" said there was nothing wrong and brought the installation manual down to prove it.

We all still learn new things every day
 
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Old 09-11-08, 06:53 PM
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biasi noise problem..Photos to show install

Thanks guys! Yeah they did a bunch of tests, I was baby sitting...so I was up and down the basement stairs every chance I got......I have the Biasi manual! So...I guess I will ask the guys about a damper. Looks like another option at some point is to replace the center section with a heavier quage or go with the double wall pipe, if thats ok with a boiler. Pics are great, too bad I can't send a "sound Byte" Bill
 
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Old 09-11-08, 07:00 PM
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I personally do not think replacing the straight pipe will make much difference. If there is enough noise to cause a concern, Either you are unsure of the normal boiler sounds or there is something wrong. I have never needed to use double walled pipe on oil systems. I have installed a couple Biasi B-10 boilers with no complaints.
 
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Old 09-12-08, 08:18 AM
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biasi noise problem..Photos to show install

Thanks Plumbingods...and everyone else! I think your correct! With my old Weil-McLain, the whole thing made a fair amount of rough noise. Now, the burner and boiler are VERY quiet...its just the exhaust noise that I have never heard before, I guess its not that loud, just a new sound! Thanks, Bill
 

Last edited by bostonfan49; 09-12-08 at 08:19 AM. Reason: spelling
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