To Cat or Not to Cat

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Dave_1

Feeling the Heat
Jul 19, 2006
306
Hi, am in need of those with Cat expertise but first some background.

I live in a rural area & our nearest neighbors are @ 1/3 mile away as the hawk flies. Our heater is a Fisher MaMa Bear which turns 27 in October & is still in excellent condition.

The stack temperature is kept @ 350-400, save at startup which is 500-600. Our walls are R-23, the attic R-57, & MaMa sits katy-wompus in a corner that has two 6’ L x 8’ H brick walls that act like an enormous heat sink. Small fires are burned that go out in @ 3 hours if not maintained. The last load is put in @ 10pm & the temp is 60-65 when I get up at 5:30, if the outside temp is @ 20. After re-lighting the temp is 70-75 within an hour.

The wood burned is at least 2-3 years old & stored in an open shed, but the south side is enclosed in glass that spans 24’ L x 7’ H. Such results in a 6% moister content (mc) reading on the sun side of any split that is a year old on my Delmhorst J-Lite moisture meter, while the back end of the split, 22“-24” in length, reads 10-12%. Give that split 2 years & the mc is the same at both ends, 6%.

Consequently I have stopped cleaning our 13-½’ chimney (7 ½’ Meatalbestos, 6’ of single wall) because the ash accumulation only amounts to a 12oz soda can.

But presently considering stuffing 2 five foot galvanized 26 ga 8” pipe down my Metalbestos sections to ensure that it does indeed last throughout our lifetimes. (About had a heart attack when I saw the price of a 30” Metalbestos section now days.) But more about that in a future post.

As the “energy crisis” goes forward there is no doubt that the Fed/states will require removal of my heater by use of tax credits & or fines. But a $400 - $600 tax credit will not replace my heater which brings me to my question.

From what I have presented above is it possible for you to determine that there would be a major environmental improvement, 60% or more reduction in pollutants, were a Cat installed in my single wall pipe? If so, please recommend reputable manufacture(s).

If this cannot be determined without testing then is there a DIY kit that can be used to make such a test, or are professionals required? (I cannot seem to find a kit on the net, but then my search parameters maybe wrong.) If a Cat would make a significant improvement in my emissions then I’d like to make the change now so that my wife can see it’s operation & learn what is required to maintain it in the event of my death.

Thanks in advance for your input.

Dave
 
Dave_1 said:
Thanks in advance for your input.

Dave

I don't think there are any commerically availabel cat retrofits these days.

The reason is not because they don't work, but rather that most older stoves have already gone by the way side so the market is small.

Give the design of a Fischer stove, I would say that a cat installed immediately above the stove might do some good when used correctly. This stove run hot flue temps which would activate it.

Then again, burning technique means a lot also, and if you don't have heavy creosote problems, you are burning OK.

OH, here's one at Woodman Associates....so they still do exist. These are good people at Woodman....

Retro Catalytic Link
 
I'm sure someone's going to have a heart attack about your idea to put stovepipe down your chimney!

Do you need 8" diameter chimney? Three foot lengths of 6" diameter aren't much more than $100, are they?

What's the worry with pollution? Creosote accumulation? Future regulation? Neighbours complaining? You should be able to get a more efficient stove second hand stove without forking out too much.
 
Craig,

Unfortunately, it appears your right as John, of The Wood Heat Organization Inc., states:

"Retrofit cats used to be available 20 years ago but they didn't work so they disappeared."

What made me think that the conversion was possible were statements like the following:

<snip>

"If you have an older wood-burning appliance, consider upgrading to one of the newer appliances certified by the U.S. Environmental Protection Agency (EPA). They include a catalytic combustor that allows combustion gases to burn at lower temperatures, thereby cleaning the exhaust gas while generating more heat. All woodstoves sold today should bear an EPA certification sticker. High-efficiency appliances not only have lower emissions but they are also often safer, since complete combustion helps to prevent a buildup of flammable chimney deposits called creosote.

If you want to retrofit an existing non-catalytic wood-burning appliance with a catalytic combustor, you can buy a catalytic damper. These are available as kits and are usually installed in the flue collar. To monitor the stove temperature after adding a catalytic combustor, you should also install at least one heat sensor on the stove body or stove pipe. Several manufacturers sell retrofit kits, and they may be available from wood stove retailers. They are not appropriate for all types of stoves. Again, be sure to follow the manufacturer's installation and operating instructions."

<snip>

http://www.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12570

and

<snip>

"Luckily, there is a course of action available that's a great deal more affordable than purchasing a complete new wood stove and that still provides much of the efficiency improvement and emissions reduction made possible by these state-of-the-art combustors. There are, you see, over a half-dozen catalytic retrofit devices on the market today, and test results show that they offer significant performance gains over a plain old airtight heater. If you're in the market for such a device, here are some of the things to look for.

Any retrofit catalyst is a compromise, because the stove that it's installed in was not designed to insure an adequate supply of oxygen and good mixing of the smoke and oxygen at the combustor. Also, add-on catalysts are often positioned farther from active flames than are designed-in units, so the temperature of gases entering them is generally lower. This means that the add-on (and particularly the external) catalyst may be reluctant to "light off" at the beginning of a burn or after refueling."

<snip>

http://www.motherearthnews.com/DIY/1984_November_December/Retrofit_Catalytic_Converters

Appreciate your help.

Dave
 
Dave pressed for time here but from your description I think you also need to take a carefull look and galvanizrs connector 26 gage pipe has no business anywhere near a wood stove.

Just like advertising everything sounds rosey and works In line cats don't really work you clogg them at startup there is no passage for the needed secondary air feed. As for as producing more heat ? what in the connector pipe secondary burn in the connector pipe ? Connector pipe being 26 ga galvanized with secondary cat light off? Would not be a situation I would want in my home
 
If you give me dimensions, I could design and fab a relatively simple new baffle that would hold a cat and a bypass gate. You could fit it in place of the existing baffle and have the best of both worlds. :)
 
elkimmeg,

Thank you for your good recommendation which I totally agree with.

I apologize for the confusion. I should not have included my remarks since my primary purpose was to get information regarding cat installation, performance, & advice for my type of heater.

However, such was not what I purpose to do with the 2 sections of galvanized pipe. Such are to be installed only inside the metalbestos sections in order to protect their inner walls.

Yes, Metalbestos claims a lifetime warranty & I’m going to ensure that their product does indeed perform that long for our sakes. By not crimping the galvanized sections the galvanized can be stuffed into the Metalbestos & yet still be removed if necessary for inspection & or replacement.

Thanks again.

~~~~~~~~~~~

Matt,

Yes, money is a factor. When I retired the company promised to pay 100% of our health care, now $10k a year comes out of a pension to pay for such. That is a large bite that was not expected.

Was asked by other retirees to go into a class action law suit against the company. I pointed out that the Supreme Court had established a legal precedent against plaintiffs for the benefit of other companies that had been litigated against.
I warned them that all they were going to was get the privilege of feeding the lawyers pot. They went ahead anyway.

Their chance of getting a Supreme Court reversal is about as good as Judas getting out of he!!.

Dave
 
Dave I can post pictures of what happes to 26 gage galvanised pipe. Save you money and let the original pipe do what it suposed to do. the galvanized sleeve will not last long And that s--ks what they did to your pention
 

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I printed that last time you posted that photo, i have it hanging up next to the galvi pipe on the shelf.
 
Corie,

Please see my 2nd post on this subject & note the quoted remarks, which were taken from the links posted.

It was because of those remarks that I came to Heath.com in order to determine whether a cat conversion would be environmental significant & how such could be done if so.

From the link that Craig gave, they claim that even if I did install a cat it will not bring the MaMa Bear up to modern EPA standards.

Consequently a cat conversion is a moot point at this time.

However, if I find out later that someone / company has done such & is EPA certified I will certainly pm you.

What dimensions do you need?

Thanks

Dave
 
I agree that the conversion is a moot point, probably on more than one level. However, if you wanted to pursue this idea, I would be happy to fab a steel baffle that completely closes off the top half of the firebox. In this baffle we could fit a cat combustor, and a sliding bypass gate.

The only thing that concerns me is the size of the firebox and the potential of the stove to produce too much heat. Don't know where you live at, but it would be easiest for me to see the unit before I considered building the retrofit setup.

But again, long run, you're probably better off picking up a used, EPA certified unit.
 
Corie said:
I agree that the conversion is a moot point, probably on more than one level. However, if you wanted to pursue this idea, I would be happy to fab a steel baffle that completely closes off the top half of the firebox. In this baffle we could fit a cat combustor, and a sliding bypass gate.

The only thing that concerns me is the size of the firebox and the potential of the stove to produce too much heat. Don't know where you live at, but it would be easiest for me to see the unit before I considered building the retrofit setup.

But again, long run, you're probably better off picking up a used, EPA certified unit.

Hey Corie,
Have you ever thought about installing a baffle into a heatilator fireplace to make it a little more clean and efficient? I was thinking of tinkering with my masonry fireplace by installing Country Flame air tight doors, lining with firebricks, and installing some kind of baffle. But then it would probably be smarter to just put an insert in there.
 
Messing with heatilators is something I probably wouldnt' recommend. The firebox, throat and chimney system are designed for the current temperatures and if you started doing things that greatly increased firebox temps, I think you'd probably end up with a fire in a place you didn't want it. That's just my opinion though. From what I've seen of prefab fireplaces, they were designed on the raw edge of being unsafe as is and anything that greatly changes their operating conditions probably moves them into the region of very dangerous.


Just be patient, I'll have a multi-fuel dual blower fireplace insert done before you can say jack-rabbit. hahah
 
Dave, I would be much more worried about the condition of your chimney - i.e. are the interior walls holding out OK - and whether that 12 oz. of creosote might actually be dangerous - than I would be about overzealous government busybodies - at least in rural areas where your neighbours are 1/3 of a mile away. Heck, even up here in Soviet Canuckistan country folks use ancient smoking "airtights" without fear of regulatory intrusion. Drive along any country road in the winter and look at the steel chimneys - well over 1/2 are smoking pretty severely. The torches and pitchforks would come out pretty quick if someone told them they all had to buy EPA stoves.

But seriously, what is the realistic service life for Metalsbestos chimney? I imagine it depends on a lot of factors. I replaced 6' of chimney last year, it was about 25 years old. It hadn't seen too much use but according to my father it had withstood 2 chimney fires. It still looked OK, at least to my untrained eye. I got rid of it mostly because I didn't like it's ceiling support/stovepipe adaptor box (totally unsafe - see my avatar) and it was an obselete type of chimney (only 1" thick wall) and I couldn't find parts that would work with it (i.e. a new ceiling support/stovepipe adaptor).

So does anyone have an idea about the expected service life, and how to inspect the condition of a Metalsbestos chimney?
 
Corie,

The MaMa Bear’s firebox dimensions are:

24” W x 20” D & the height is 16” for the first 9” going from front to the back. But after 12” the interior height is then 22” since this is a two level heater. And the width increases to 26 ½” in this area since there are no fire bricks after 13” off the bottom.

There is an 8” flue that is centered in the back of the heater @ ½” from the top. There is a ¼” thick x 4” D x 12” W flange(?) centered directly under the flue. The distance between flange & flue is @ ¼”. From the bottom to the flange is 13”.

As to your concerns about excessive heat, please read my first post & note that we do not build large & or overnight fires. The wood that we burn has a moisture content of 6%. That is the truth & proven regularly by my Delmhorst J-Lite meter & the small yearly ash accumulation.

There are two spin knobs on the front doors for fire control & the heater has no gasket. The salesman said that if we correctly loaded & fired it there was no need for gaskets.

I will keep searching the web to see if anyone has had success. If they have & are EPA certified I will contact you for a price.

Thanks much.

Dave
 
my .02 dave, before you modify any stove beyond the simple cat retrofit, a few points to consider : you may not build large fires or overnight burns, but you open yourself up to all kind of liability situations. If and when you sell your house the new owners might burn it hot and overnight, and possible burn the house down, then they come after you. The next point would be pyroformic carbonization, the wood behind the stove that is safley within current clearances,(modified stoves wont have any tested clearances) over time will carbonize, reducing the combustion point of the wood and ultimatly catching fire. One way around this is to default to the minimum 36" clearance for non listed stoves. This only applies to the stove modification, not the pipe combustor.
 
Matt,

“Soviet Canuckistan” (Lol) I hear ya, but you better not let your Prime Monster! (lol)

My fault if you thought the 12 oz was totally creosote. To me it appears as ash. The walls of the Metalbestos are grayish black. There are no flakes of creosote hanging off the pipe as I’ve seen in other chimneys.

But without dismantling & scrubbing the Metalbestos pipe, with a soft brush & soapy water, I cannot be certain that there are no pin leaks. Rather then go thru that work it is quicker to stuff the galvanized down the Metalbestos. Inserting such is merely a safety precaution to ensure that the Metalbestos pipe remains undamage.

(That picture that Elk posted is an excellent warning to those of why never run such pipe directly to a heater. Then there is also the matter of gas poisoning the inside house air.)

As for the general populace out here, you are right. Some of the clunkers that pass by probably emit more pollutants then our heater. (lol) I once read that 10% of the cars in the states make 90% of the car pollution. Rather then tightning standards the EPA needs to locate the owners, buy the junker, & then help them finance a decent car. It would be a lot cheaper.

I want to do the right thing, especially for the wife. If I can resolve this now then she has no worry about being EPA compliant if I‘m dead. That is my goal. That stunt pulled by my former company with health insurance was a wake up call. What is good today may not be tomorrow. So I have a five year supply of wood under the shed & intend to increase that to 7 years this winter.

What the civilized world needs is a “Manhattan Project” in converting water into fuel. Once that is achieved the fruit cakes can eat their sand & drink their oil, perhaps then they will realize that such is not a healthy diet?

Thanks for your concern.

Dave
 
MSG,

You make good points.

If I’m dead, Alzheimer afflicted, hospitalized, etc the wife knows the heater’s operation. That is why I want to install acat now, if EPA compliant, so that she can learn the drill.

We have no intention of selling, but then again could be forced due to circumstances beyond our control. So I will prepare heater operation instructions tonight which prospective owners will be required to sign that they have read & will follow the instructions, & that they relinquish all legal recourse against us in the event there is a fire accident. No sign, no buy.

As for “carbonization”, my office sits directly behind one side of the brick veneered heater’s wall. I have an inside/outside thermometer for that wall. The outside probe is inside the 1” airspace cavity & measures the heat at the top of that wall. I have yet to see it reach 110 degrees. From what I’ve read, & please correct me if such is erroneous, 140-160 degrees is the maximum sustained tempeture that such heater brick walls with studs should be subjected to.

Sorry about the 20 degree variance in temp, but it seems that this is left to the author's opinion since they never document where & how they got their figure(s).

Thanks for your insight, especially the suing part as the following loving daughter so perfectly illustrates.

"An Illinois woman is suing her Wisconsin parents for maintaining an icy driveway that she blamed for a fall that broke her ankle two winters ago. "

http://www.local6.com/family/9513070/detail.html

And after thinking about not being able to see my thermometer in the brick cavity, unless in the office, I went searching.

Sensored. This expandable wireless thermometer system provides both indoor and outdoor temperatures in one reading. Remote sensor sends signal to thermometer up to 100 feet away. Add up to two additional remote sensors (#63-1092). Set on desktop or mount on wall. Display readings in Fahrenheit or Celsius.

* Get both indoor and outdoor temperatures in one reading

* Remote sensor sends signal to thermometer up to 100 feet away

http://www.radioshack.com

Or try this $26 one that reads to 392 degrees

http://www.ambientweather.com/aworscwibbqt.html

These would allow people in the heater's room to know what the temp was behind the wood heater's brick wall.

Perhaps your customers would like to know about these units? I know I sure would have had they been available when I built my house.

Thanks again.

Dave
 
Dave,

can u send a pic of your stove. it sounds like my unidentified fisher. i have been looking around as to wat i should do for more efficiency id be interested to see how the baffle helps if you do get one fabricated.

thanks

cody
 
yetty734 said:
can u send a pic of your stove. it sounds like my unidentified fisher. i have been looking around as to wat i should do for more efficiency id be interested to see how the baffle helps if you do get one fabricated.

Hi Cody,

Ok, does your stove look like my avatar?

The outside measurements are: 27 - 3/4” W x 22 - 1/2” D x 24” H (lower front) 30-½” H (back top)

Get a large cardboard box & use it as a pattern for your Fisher’s baffle.

Next check a junkyard for a piece of steel that is 3/16” or ¼” thick which can be cut to fit that pattern.

In my Fisher a baffle (26-3/4” w) will span the firebox sitting atop the highest firebrick on the sides. The stove’s flue exits the back & there is a small smoke shelf directly under it. From the back of the stove to the front is 22”.

My baffle is 26-3/4” W x 12” D which reduces the amount of the wood the fire box can hold, so consider that before you cut steel.

When in operation the baffle should be pushed back to butt against the rear of the stove & sit atop the smoke shelf in order get support on three sides. When it is it causes most of the fire to come forward 12 inches slowing the exit of heat out of the stove which increases the stove’s efficiency.

When starting a fire pull the baffle to the front using the heel of a poker or glove. That will allow the fire to exit the flue preventing smoke from being dumped into the room. Once the fire catches push the baffle back until it butts against the rear of the stove & sits upon the smoke shelf.

Another thing that will increase any heater’s efficiency is lowering the moisture content of the wood. The following links should help.

Moisture meter use & wood storage

https://www.hearth.com/econtent/index.php/forums/viewthread/3558/P15/

https://www.hearth.com/econtent/index.php/forums/viewthread/4501/P15/#47684

https://www.hearth.com/econtent/index.php/forums/viewthread/3359/

BB,

The only fireplace insert I‘ve operated was a five 2” exhaust pipe configuration that I designed & had a muffler shop make. This was about a year before someone showed me a picture of a Heatolator (spelling?) equivalent with enclosed glass. Thus I cannot speak to your Sierra operation regarding air control. And what a pre-EPA heater, i.e. Buck, etc, will do is also beyond me.

I only know that MaMa operates very efficiently by the procedure I’ve given, as witness a 12 oz soda can accumulation for @ a 17 year run without my sweeping the chimney. I’ve had people comment, that since they didn’t see smoke they thought that I was heating with ng, as they were up wind to the chimney when they came in our house.
 
Anyone can get the mc down to 6% by laying down 6 mil plastic, landscape timbers on top, point the cut end to the un-shaded sun, protect the wood by glass, & store it under roof. Just try that experiment for kicks & let the forum know what you learn.

Have a good one,

Dave.
 
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