white stuff on Power Vent

billygoat22

I saw the Tjerlund CCS1 on another site (www.tjernlund.com) while looking at oil filter accesories. I recall seeing something about the vent being oil only, but couldn't see model number in your picture. Manufacturer spec.s are on the site for their units- you could check the requirements against the install and perhaps ask them also.

GW

what is this white stuff

It's calcium like, it will scrape off but it's really stck on there...

Gary

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Mark Hunt

That


is the effect of carbonic acid eating the galvinzed metal on that power vent.

There is some condensation going on with what ever it is attached to.

The flue pipe shows signs of this as well.

Something is going on that needs to be looked into.

Mark H

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[Deleted User]

Looks like

condensate corrosion. Is there adequate relief air in the mechanical room to dilute the flue gas and keep the stack dry? That's when I usually see this on atmospheric fired gas appliances. No relief air causes the stack to sweat internally, causing this byproduct of corrosion.

ME

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GW

basement

It's about a 1000 or so wide open basement... I did bring up the temp on the Viessmann Vitola 33 natural gas by knocking out 4 holes in the chamber... the system is only 3 years old. I replaced the 26GG. The post purge is about 8 minutes. Do you think it needs more air?

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[Deleted User]

I don't remember the source...

and I tried to do a Google search on it to no avail, but the gist of theinformation was this, wihtout adequate dry dillution air to be mixed in with the stack draft, the flue gasses are laden with moisture and will condense. Simply having a large open space connected to the area of combusion doesn't necessarily satify this need. The demand for dillution air for the stack effect is very substantial, and if left unmet will cause the stack to condense.

Nick Wilder introduced me to the article, maybe someone book marked it. In any case, I'd make sure you have adequate outside air being introduced into the area of combustion.

Maybe Mark Hunt will also chime in and talk about worst case scenario depressurization.

If left unattended, the flue pipe will rot out in a relatively short period of time.

Knowing you as I do, I know it will NOT go unattended.

ME



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GW

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ScottMP

Ahhh

But whats the solution ?

I thought for a moment Gary was in my area. I have a power vented water heater that I just looked at with the same problems. I agree and the answers make sense about moiture, but whats the solution ?

My customer also has a wide open basement, but its a old carriage house with field stone walls, run off water from the hill behind it, which all make it very damp.

Another customer has two power vented boilers with a dirt,damp, floor. We constantly have to be alert to his flue pipe conditions. The moisture in his combustion air is killing the flue pipe.

Anyone ??

Scott

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Mark Hunt

Short of


a good dehumidifier there isn't much you can do. If the moisture problem is that large the customer should consider other drainage options.

As for depressurization, we would have to see what the combustion appliance zone was doing when any and all exhaust fans were running.

According to the BPI protocol, a power vented appliance may be allowed to operate down to -50pa. I haven't found a home yet that has gone that negative.

Mark H

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hr

What temperatures

Are you running on the boiler. All non condensing boilers need to run above condensing temperatures on every cycle, long enough to dry both the HX and vent piping. Hard to put an exact number or time on that, depends on a lot of variables.

If their is a possibility of short cycles, ocassionally, you may not be getting the components warm enough to dry, hense the corrosion. Just a thought.

hot rod

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Art Pittaway

Flue size

might be to large. I just replaced the one in my house and the 8" that was installed was rotted out. When I calculated the size I couldn't add enough fudge-factor to get it over 5". All installed with a correct Y-fitting and it draws just fine. The 8" just became a big condensor and the flue gas stops and makes carbonic acid.
My opinion. Art

Unknown

Corrosion

I have a number of questions.

1. Which way is the flue gas moving in that photo left or right?

2. Is this side wall vented?

3. Whose Power Venter is it?

4. Carbonic Acid - you can not use galvanized 26 gauge flue pipe on condensing appliances.

5. You will find that installing a dehumidifer is a must to prevent these problems.

6. What is the size of the room length-width-height?

7. What is the total BTU's in the room?

8. What is the stack Temperature?

9. What is a 26 GG?

10. Why is the post purge so long 8 minutes???

Remember for 100,000 BTU's a gallon of water is formed per hour.

You need a minimum of about 30 cubic feet of air per 1,000 BTU's a little less with Power Venting.

Dilution air and air for combustion have to be below 50% humidity and really no more than 60% and that assumes a stack temp over 275 degrees (F). Condensate is possible even with temp over 275.

-50 pa for power vented is related to a dedicated Power venter designed for the equipment. If it is a retrofit watch out for RPMS above 3500. Keep in mind that everything after the power venter is at + pressure and must be tight. You can not use "B" vent or galvanized that is not sealed.

What is the flue size and how long is the flue pipe.

HOW AM I GOING TO GET ALL OF YOU TO MY CLASSES ON AIR FOR COMBUSTION, VENTING, CO TESTING AND COMBUSTION TESTING. YOU SHOULD NOT BE OUT THERE DOING THIS STUFF UNLESS PROPERLY TRAINED.

Gary get me some info and I will try to get a solution for you. The white stuff is a reaction from galvanized pipe and carbonic acid with high moisture content. There is also some evidence of Nitric oxide (NO) and nitrogen dioxide (NO2) collectively called (NOX)being deposited with the moisture that is causing this problem. With all the new mid efficiency and high efficiency equipment moisture and air are critical factors that have to be addressed. Some of this equipment should not be installed in basement and crawl spaces especially with dirt floors and a lot of damp wet air.

billygoat22

flue

You didn't mention if the basement was heated or if water came out during operation of (sidevent?) unit. most of the high eff stuff says you need to insulate the flue in unconditioned spaces. I check all chimneys or flues for sizing and a liner- saw one pipe rust out in six months and had a pile of melted wax looking stuff under the draft hood on the boiler

Mark Hunt

\"How am I going to get all of you to my classes...\"

> I have a number of questions.

>

> 1. Which way is

> the flue gas moving in that photo left or

> right?

>

> 2. Is this side wall vented?

>

> 3.

> Whose Power Venter is it?

>

> 4. Carbonic Acid -

> you can not use galvanized 26 gauge flue pipe on

> condensing appliances.

>

> 5. You will find that

> installing a dehumidifer is a must to prevent

> these problems.

>

> 6. What is the size of the

> room length-width-height?

>

> 7. What is the total

> BTU's in the room?

>

> 8. What is the stack

> Temperature?

>

> 9. What is a 26 GG?

>

> 10. Why is

> the post purge so long 8 minutes???

>

> Remember

> for 100,000 BTU's a gallon of water is formed per

> hour.

>

> You need a minimum of about 30 cubic

> feet of air per 1,000 BTU's a little less with

> Power Venting.

>

> Dilution air and air for

> combustion have to be below 50% humidity and

> really no more than 60% and that assumes a stack

> temp over 275 degrees (F). Condensate is possible

> even with temp over 275.

>

> -50 pa for power

> vented is related to a dedicated Power venter

> designed for the equipment. If it is a retrofit

> watch out for RPMS above 3500. Keep in mind that

> everything after the power venter is at +

> pressure and must be tight. You can not use "B"

> vent or galvanized that is not sealed.

>

> What is

> the flue size and how long is the flue pipe.

> HOW AM I GOING TO GET ALL OF YOU TO MY CLASSES ON

> AIR FOR COMBUSTION, VENTING, CO TESTING AND

> COMBUSTION TESTING. YOU SHOULD NOT BE OUT THERE

> DOING THIS STUFF UNLESS PROPERLY TRAINED.

> Gary get me some info and I will try to get a

> solution for you. The white stuff is a reaction

> from galvanized pipe and carbonic acid with high

> moisture content. There is also some evidence of

> Nitric oxide (NO) and nitrogen dioxide (NO2)

> collectively called (NOX)being deposited with the

> moisture that is causing this problem. With all

> the new mid efficiency and high efficiency

> equipment moisture and air are critical factors

> that have to be addressed. Some of this equipment

> should not be installed in basement and crawl

> spaces especially with dirt floors and a lot of

> damp wet air.





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Mark Hunt

\"How am I going to get all of you to my classes...\"


Well, you could start by offering FREE BEER. However, I know that you would NEVER offer such a thing.
"Walk in the spirit and ye shall not fulfil the lusts of the flesh".

So I guess you need to knock and keep knocking.

Timmie!! When you get close to my neck of the woods I'll be there!!!!!!!

Mark(Romans 8:1)H

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Herb

sidewall venting

Our utility now requires the use of B-vent from the gas appliance to the powervent assembly. Of course, the unit should be on an outside wall with sealed passages from the blower to the hood. What you're seeing is very common with the use of 80+ efficient equipment. Lots of care must be used with their vents to avoid the problems of condensation or better yet consider the benefits of 90+ condensing equipment.

GW

answer


> 1. Which way is the flue gas moving in that photo left or right?

flowing Right- this power venter is side wall mounted

> 2. Is this side wall vented?

yes

> 3. Whose Power Venter is it?

Tjunlund SS1

> 4. Carbonic Acid - you can not use galvanized 26 gauge flue pipe on condensing appliances.

It's not designed as a condensing boiler, although it is a low temp outdoor reset boiler


> 5. You will find that installing a dehumidifer is a must to prevent these problems.

>6. What is the size of the room length-width-height?

It's about 1000 sq ft, 8 foot ceiling

> 7. What is the total BTU's in the room?

116,000

> 8. What is the stack Temperature?

300 plus, it was climbing

9. What is a 26 GG?

yes
> 10. Why is the post purge so long 8 minutes???

don't know, how many minutes should it be?

> Remember for 100,000 BTU's a gallon of water is formed per hour.

> You need a minimum of about 30 cubic feet of air per 1,000 BTU's a little less with Power Venting.

> Dilution air and air for combustion have to be below 50% humidity and really no more than 60% and that assumes a stack temp over 275 degrees (F). Condensate is possible even with temp over 275.
>
> -50 pa for power vented is related to a dedicated Power venter designed for the equipment. If it is a retrofit watch out for RPMS above 3500. Keep in mind that everything after the power venter is at + pressure and must be tight. You can not use "B" vent or galvanized that is not sealed.

> What is the flue size and how long is the flue pipe.

the breech is 5", so we have about 12-14' of 5", then we increase into a 6" x 24", which is were I installed the Barometric (yes, it's dual swing, that 2' pipe ties into two 90s (6"), which is what you see in the photo.

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DanW

I think I'd consider a stainless pipe long before a dehumidifier.

GW

gas OK

there site says so

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Glen

white stuff -

> there site says so

>

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 171&Step=30"_To Learn More About This Contractor,

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> Contractor"_/A_

Glen

white stuff

Are any pool or cleaning chemicals stored nearby? Even very same amounts of chlorinated products will chew through a vent in a very short time.

GW

good question

They do have a spa- I better find out

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