Kuuma wood gasification furnace?

[ziggo_2]

How are you measuring the flue temp? magnetic surface or an internal probe type? I'm guessing magnetic being that low. Pretty impressive! Have you ever tried measuring the temp of the hot air coming out of the top of the furnace?

Probe....Im heating the house no problem its just really low flue temps, my chimney is outside so that makes it worse. I should clarify that its more like 300 - 500 in the flue pipe but once it hits the chimney it drops instantly. I can keep it from condensing but then it but then i sacrifice burn times and wood. Not trying to hi-jack this thread with my problems, im dealing with them myself.

But id like to know how Kuuma can have such low flue temps and not condense?

 

[Como]

Probe....Im heating the house no problem its just really low flue temps, my chimney is outside so that makes it worse. I should clarify that its more like 300 - 500 in the flue pipe but once it hits the chimney it drops instantly. I can keep it from condensing but then it but then i sacrifice burn times and wood. Not trying to hi-jack this thread with my problems, im dealing with them myself.

But id like to know how Kuuma can have such low flue temps and not condense?

You can't.

At temperatures below 250 degrees F creosote will condense on the surfaces of stove pipes or chimney flues.When the temperature gets below 150 degrees F the creosote deposit will be thick, sticky and similar to tar. This tends to trap carbon from smoke which dries and bakes inside pipes and flues. This flaky substance is very flammable.

Chimney Problems

Now with Propane and NG high Efficiency furnaces, Boiler etc you will see the term condense used. That does produces very low exhaust temperatures allowing plastic pipe for a chimney but also requires a drain for the moisture that condenses.

I do not know of any wood system that condenses, the technical aspects are beyond me, my gut tells me it is not possible or if theoretically possible worth the consequent problems.

My guess is that it is a question of temperature measurement. Insulated pipe?

 

[cfarms]

Yeah, I'd have three wings on my house and get these 2 and 1 from Keith to see which one actually worked best.:msp_biggrin:

Spread the wealth a little.

Just so you guys know, Keith doesn't work with Yukon anymore. He has moved out of town.

 

[3fordasho]

You can't.


My guess is that it is a question of temperature measurement. Insulated pipe?

THIS... Measuring flue temps with a magnetic stick on thermometer or a probe type that has it's coil outside the pipe (condor flue thermometer) can give VERY inaccurate readings, especially if you're using double wall connector pipe. The only readings I would trust are a thermocouple type inside the connector pipe, or probe type that has it's coil inside the probe itself (Tel-Tru or similar).

I had a condor probe type installed in double wall connector pipe about 18" above the stove and it read low all the time and was slow to respond. I later discovered part of the reason for that is it was installed in a telescoping section of pipe which is 4 layers of steel not just two. That said I much prefer a probe type made by Tel-Tru for the big green egg - about $20 and reads to 1000f. Accurate and fast response as long as you dont over temp it.

 

[ziggo_2]

Just so you guys know, Keith doesn't work with Yukon anymore. He has moved out of town.

I was wondering that....since i never see him post anywhere anymore.

 

[mizzou]

Just so you guys know, Keith doesn't work with Yukon anymore. He has moved out of town.

I wondered, last post I saw wasn't too long ago, but was about people trying to stop anyone from burning wood. I suspect he still lurks.:msp_sneaky:

 

[iowa]

OK. So the questions were how I was measuring my flue temp. I do have a magnetic temp on my SINGLE WALL flue pipe. I have regular black stove pipe running from furnace to my wall thimble. Then it's double wall selkirk 6" stainless from wall T thimble all the way up.

I do look at the magnetic temp gauge. Is it accurate? No. So I have been using my infered thermometer. Last night after loading it I was getting 180-190 deg allong the top side of my stove pipe. This probably isn't the hottest it will be as it wasn't in the middle of a burn, but I will try and get some reading then. I do have a temp probe and will drill a hole 8" from the furnace and insert it. See what it measures that way.

I will also try and take pics of inside my flue pipe so you guys can see first had what I'm talking about. I know you all think that I should have creasote tar stuck to the inside and running out my seams of the pipe. But I don't. And I know from previous experience with my old long wood, that if I didn't keep my stack temps above 400deg it would get nasty. And it did! Last yr I had creasote everywhere since it was such a mild winter. My stack temps where low around 300deg. And that was measured with the magnetic thermometer. I could smack my flue piping and hear crap fall down the chimney. Every time I took off the clean out cap, creasote would fall out.

I've taken my cap off once this yr. Just last week and looked up the chimney. Nothing... Only stains from the last 4 yrs of creasote. There was just a little grey dust on the edges. Nothing fell out on the cap!!!

 

[brenndatomu]

I wondered, last post I saw wasn't too long ago, but was about people trying to stop anyone from burning wood. I suspect he still lurks.:msp_sneaky:

If you look, that thread was an old one that someone dug up. I just looked it up, CK hasn't signed into AS since 9/3/2012.

 

[iowa]

BTW!! I am not paid by Kuuma to say this or that. In fact after talking to Keith on the phone last yr. and him telling me about flue temps and burning wood, I was totally against getting a kuuma furnace!!! I thought it was snake oil, BS... NO LIE...

I waited though and followed the threads on here and thehearth. I pm'd a few guys and asked questions about their kuuma vaporfires and heard first hand that it isn't BS. So I decided to go with one and see for myself. I like taking risks. Some pay off... Some don't. I'm glad I took the plunge. Was it expensive? $4800 shipped here with a water coil. You tell me? I pay $2000 on average with proPAIN a yr before burning wood. With my old longwood I was going through 5-8 cord a yr to keep my house warm. I'm hoping I will only go through 4cord or less a yr with the kuuma. Right now I haven't gone through one cord this yr.

 

[lampmfg]

You can't.

At temperatures below 250 degrees F creosote will condense on the surfaces of stove pipes or chimney flues.When the temperature gets below 150 degrees F the creosote deposit will be thick, sticky and similar to tar. This tends to trap carbon from smoke which dries and bakes inside pipes and flues. This flaky substance is very flammable.

Chimney Problems

Now with Propane and NG high Efficiency furnaces, Boiler etc you will see the term condense used. That does produces very low exhaust temperatures allowing plastic pipe for a chimney but also requires a drain for the moisture that condenses.

I do not know of any wood system that condenses, the technical aspects are beyond me, my gut tells me it is not possible or if theoretically possible worth the consequent problems.

My guess is that it is a question of temperature measurement. Insulated pipe?

The combustion efficiency is high enough to burn up to 99% of the smoke. So when you get rid of the smoke you get rid of the creosote. In simple terms "No Smoke=No Creosote". We have enough flue temperature so the water vapor doesn't condense until it hit's the atmosphere. With complete combustion (important) the two by products are water vapor and CO2. It stays as a vapor because the temperature is more than 212 degrees all the way until the top of the chimney top. :confused2:

 

[laynes69]

We had problems with condensation the first year of our furnace. Our flue temps are low, but the chimney liner was too big. We lined the chimney and our condensation problems disappeared. Our flue temps stay around 200-225 external on average. We don't have a single problem with condensation, and there's no creosote buildup. The insulated liner keeps the gasses hotter. Our old furnace flue temps would easily go over 400 external on the fluepipe.

 

[stihly dan]

Happened to be in the middle of a burn now. unit is on low as always, 186 deg f. 18 inches away from furnace, top of single wall pipe, with infrared and magnetic.

 

[ziggo_2]

Happened to be in the middle of a burn now. unit is on low as always, 186 deg f. 18 inches away from furnace, top of single wall pipe, with infrared and magnetic.

internal temps are usually hotter than surface temps. I use a probe, it only goes up to 550 but thats hotter than i want it anyways. I also have a magnetic thermometer but i dont pay much attention to it anymore. I actually put it above the door on the front of the firebox. (should just throw it in the firebox)

 

[iowa]

Ok guys. Its show and tell time! I put 5 pieces of wood in right before supper. I ate and went back downstairs 30-45 min later. Theres a good hot fire going and perfect for taking temps and pics of flue pipe.

I took my temp probe I use for my smoker. Inserted it 3" into stove pipe approx 16-18" away from furnace. It moved around between 350-415. So if you wanna take a medium of 385ish??? My infered thermometer was around 200 on the stove pipe. Here's some pics. The pic with the temp probe displays 2 temps. The top temp is what the probe is sensing. The bottom number is your preset number. It beeps once it hits that desired temp.

 

[ziggo_2]

I measure my temps about a foot AFTER the BDR, Looks like your temps are right around where they should be. My flue temps are fine until they hit the chimney. I think it comes down to having an outside chimney, although it seems nobody else has this problem on their outside chimney. Its not "wet wood" either so I dont know.

 

[iowa]

Mine is an outside chimney. Runs next to the side of my house. Through the soffit and goes 4' above roof.

 

[brenndatomu]

Does the Kuuma tie into the house thermostat? Does it overshoot the thermostat set temp sometimes?
I wouldn't think you could maintain a "smokeless" burn if the fire is dialed back too far, therefore, if the heat load is light, I'm thinking ya must hafta use the windowstats sometimes, ehh?

 

[iowa]

Yes. Its hooked to house thermostat. And yes. On warm days it will overshoot the setting. We've had the winders and doors open a few times this winter. Fresh air is great!

 

[lampmfg]

Order a Kuuma Vapor-Fire on 1/17/13 or 1/18/13 and receive our H20 coil for heating domestic water (a $200 value) FREE. Must e-mail us at [email protected] and mention arboristsite.com. Only new purchases on 1/17-18/13 will be considered.

 

[Como]

Order a Kuuma Vapor-Fire on 1/17/13 or 1/18/13 and receive our H20 coil for heating domestic water (a $200 value) FREE. Must e-mail us at [email protected] and mention arboristsite.com. Only new purchases on 1/17-18/13 will be considered.

That sounds an excellent idea, discount but I was focussing more on pre heating water to mitigate usage.

Makes you wonder if you could also use it for radiant heat in a location where it would be easier to pump water than blow air.