Uh oh...what's this?!

[brenndatomu]

I looked for quite a while (maybe not hard enough), can't seem to find firebox size of the vf 100/200?

Vf200 = 3.3CF
Vf100 = 4.1CF

 

[NoobTube]

Curious are your homes single level and what square footage are you at? Also how many cords do you anticipate going through this year?

 

[Case1030]

Like bren said, it's not an issue at all when not in the mode of trying to burn wood fast. Then it's just a minor nuisance. I don't ever load on a crazy amount of coals though, as this will only push the issue down the road and make it even a bigger issue then.

Type of wood also makes a big difference. I'd think burning pine during the real cold nights would work out great for needing to load aggressively. It doesn't leave much for coals and pretty much turns to powder. Just need to re-load more, as I could probably only fit 30-40lbs of pine in my firebox. I heard Elm is similar.



4.1CF for the VF100

What I've found, long as I pull the coals to the front of the furnace I can actually load on a decent bed. Obviously can't fit as much wood in the fire box but by the time the logs are in their peak burn the coals are chewed up.

Only when I got behind on my heating is when the couple splits of pine ontop of the coals WOT realy gets the job done...

I'm curious. If you ignore the high temp alarm (which my understanding is mainly a warning) can you still load on decent coal bed with the coals over the grate? Not sure if you tried that... but I'd think you would have the same experience with the coals melting down faster?

 

[brenndatomu]

Curious are your homes single level and what square footage are you at? Also how many cords do you anticipate going through this year?

Mine is a brick cape cod style from 1940, with ok insulation. 1200 sq ft basement, the same on ground floor, then another 650 sq ft upstairs. The basement is partially finished.
I usually use 4-5 cords per year depending on how long heating season lasts...and we are 100% wood heat.

 

[JRHAWK9]

I'm curious. If you ignore the high temp alarm (which my understanding is mainly a warning) can you still load on decent coal bed with the coals over the grate? Not sure if you tried that... but I'd think you would have the same experience with the coals melting down faster?

The high temp doesn't get triggered all the time, but yeah, I load on a bunch of coals every time when it's cold out.

I sometimes use a piece of dimensional lumber to burn coals down. Burns hot and doesn't really leave any additional coals.

What I normally load on in the dead of winter. Even more when I have to push it.

 

[JRHAWK9]

Curious are your homes single level and what square footage are you at? Also how many cords do you anticipate going through this year?

Log cabin style with 23.5' tall 12/12 pitch roof. ~1,300SF main, ~1,300SF basement and an additional ~500SF loft. Have ~32,000CF of air space though due to the tall ceilings and no attic space. So equivalent airspace to heating a rectangle building with a 32'x42' footprint with almost 24' tall walls........or a 2 story home w/ 8' walls totaling ~4,000SF including the basement.

The basement is heated just from radiant heat off the Kuuma. The furnace area (~1/4 of the basement) stays roughly the same temp as the rest of the house. The other part of the basement, which is walled off and only has an open doorway joining the two areas, stays 4-5° cooler or so.

I burn, on average, 16,000 lbs of wood in a heating season. Convert that to whatever species suits your fancy.

 

[sloeffle]

Gotta get your hands on some pine. Rake coals forward and toss a few splits on top wide open... good heat output and melts the coals to powder.

I found the same thing with ash (although I was burning borderline seasoned ash.)

Very few pines in this part of the country. We are in prime hardwood country. The only pines that are around are in people yards.

I have more ash on the ground right now than what I'll burn for the next 10 years. Unfortunately a lot of it is going to waste because I can't get to it fast enough. I keep telling my neighbors to come over and get it but they are getting ash from other people too.

 

[sloeffle]

Curious are your homes single level and what square footage are you at? Also how many cords do you anticipate going through this year?

My home is a ranch. We are heating approximately a little over 2,200 of living space plus a 768 square ft basement, so we are close to 3k square feet total. The 768 square feet of living space we added along with the basement is insulated extremely well ( R60 in the attic, foamed 2x6 walls, low E windows, foamed basement walls ) and the other 1,400 square feet is insulated okay.

I burn around 1.5 - 2.5 cords of hardwoods a year depending on the winter. This year I am at about 1.5 cords burned already. Unlike some of the others I don't burn full time. I only burn when day times temperatures are below 35 - 40. We have geothermal heating / cooling so I can easily heat my house for a $1 - $1.50 a day during mild winter days. IMHO it costs more to burn wood than that. The house gets too hot otherwise if I try to heat it with wood in those temps. I'd rather be cold than hot.

 

[brenndatomu]

Never ceases to amaze me...it warms up a little bit and this place shuts down like a Chinese buffet after a health dept inspection! Its February folks...winter aint over yet!

 

[sloeffle]

Trying to hang with @JRHAWK9 and @laynes69 in how warm I can keep my house. During the cold snap I was loading the wood furnace pretty heavy. I might of put two too many splits in the furnace late yesterday morning.

 

[JRHAWK9]

The polar vortex has left and we are now in "spring mode" for a few days. I think mother nature needs to be on bi-polar medication. In about 51 hours our temps went up 69∙°. 75 hours later we are now up 78° and everything is melting.

Starting with 1/25 and ending on 1/31, six out of these seven days we had HHD's of 70+ (75, 78, 71, 58, 71, 84 , 84). The LP furnace ran way less than I expected it to during this stretch. It did run 25 minutes on the morning of the 26th due to a botched loading the night before by yours truly. It then did kick in the morning of the 31st when it was -37° out and ran on/off for 86 minutes. By this time the cold had really set in and the basement was starting to cool down. Once this happens it makes it hard to heat, as my supply temps are down which then means the supply volume are also down. This then leads to a snowball effect. So, this cold snap cost us ~$2.50 in LP.

Yesterday was above freezing and the house temp was high enough. I decided to shut down the Kuuma to clean the HX and to look at my stove pipe. I have had a OAK attached to my BD since the very first fire this fall and wanted to see how things looked after being sent ice cold air from this last cold snap. Coldest temp I've seen being sent directly into the flue was -5° the morning it was -37°.

Cleaning the HX was a piece of cake, seeing it's just all white/tan flyash. I just take a Scotch Brite scour pad and simply pass over all the metal areas and the flyash just falls right off exposing nice clean bare metal. I access the HX from both the front cleanout cover as well as through the rear flue collar. There is always ZERO creosote in the HX area, so it makes it real easy to get everything cleaned up real nice.

The stove pipe even looked great. I know very early on, when I was doing cold starts every day, sometimes twice a day, I did see some signs of stage 1 creosote right at the BD tee when I peaked past the BD. All I saw yesterday when I removed my stove pipe, was flyash. There was some loose stuff in the stove pipe which I was able to vaccum up. Here's a photo of the stove pipe right at the BD tee after I simply ran a vacuum over it. You can see where I stopped vacuuming up near the 45° elbow at the top of the photo. It's all just simply flyash.

Looks like the stage 1 creosote I was seeing early one just flaked off once I was able to start burning 24/7.

Remember, the area in these photos are where the, already low temp, flue gasses get mixed with cold outside air.

 

[JRHAWK9]

Trying to hang with @JRHAWK9 and @laynes69 in how warm I can keep my house. During the cold snap I was loading the wood furnace pretty heavy. I might of put two too many splits in the furnace late yesterday morning.

View attachment 240007

I did the same thing yesterday after I got done with the cleaning. It was 77° in here

 

[laynes69]

Yeah, it was 77 in our house yesterday lol. I'm back to small fires.

 

[brenndatomu]

Yesterday was above freezing and the house temp was high enough. I decided to shut down the Kuuma to clean the HX and to look at my stove pipe. I have had a OAK attached to my BD since the very first fire this fall and wanted to see how things looked after being sent ice cold air from this last cold snap. Coldest temp I've seen being sent directly into the flue was -5° the morning it was -37°.

Cleaning the HX was a piece of cake, seeing it's just all white/tan flyash. I just take a Scotch Brite scour pad and simply pass over all the metal areas and the flyash just falls right off exposing nice clean bare metal. I access the HX from both the front cleanout cover as well as through the rear flue collar. There is always ZERO creosote in the HX area, so it makes it real easy to get everything cleaned up real nice.

The stove pipe even looked great. I know very early on, when I was doing cold starts every day, sometimes twice a day, I did see some signs of stage 1 creosote right at the BD tee when I peaked past the BD. All I saw yesterday when I removed my stove pipe, was flyash. There was some loose stuff in the stove pipe which I was able to vaccum up. Here's a photo of the stove pipe right at the BD tee after I simply ran a vacuum over it. You can see where I stopped vacuuming up near the 45° elbow at the top of the photo. It's all just simply flyash.

Yeah I decided to do the same here this morning...thought it would only take me an hour...but it took 2 'til I got done screwing around...missed church services because of it...oops!
Mine looked pretty much the same as @JRHAWK9 's...all flyash and light dry fluffy soot. Knocked it off with the Sooteater and sucked up with the shopvac. I just fired back up now and it appears that the flue temps are down about 50* from where they had been running on the top end of the range, when the firebox is still building to normal operating temps. I'm expecting to see the 2* that I've lost off my peak plenum temps to return too.
This is before cleaning (obviously) not sure why, but the picture makes the buildup look way worse than it was. (thicker/heavier) I have the same direct connect OAK setup that JR does, and pretty much the same results...
HX before cleaning...

 

[JRHAWK9]

This is before cleaning (obviously) not sure why, but the picture makes the buildup look way worse than it was. (thicker/heavier) I have the same direct connect OAK setup that JR does, and pretty much the same results...

Your clingers probably stayed clinging because of the flatter slope on your stove pipe. My buildup on the pipe looked less, but I had some accumulated at my 45° bend at the collar. They probably couldn't hang on anymore at 45°. All I did was vacuum it and it cleaned right up.

I just fired back up now and it appears that the flue temps are down about 50* from where they had been running on the top end of the range, when the firebox is still building to normal operating temps. I'm expecting to see the 2* that I've lost off my peak plenum temps to return too.

Same here, my plenum temps went back up and my flue temps went back down. Crazy how much a thin layer of flyash can insulate the metal in the HX.

 

[brenndatomu]

Your clingers probably stayed clinging because of the flatter slope on your stove pipe. My buildup on the pipe looked less, but I had some accumulated at my 45° bend at the collar. They probably couldn't hang on anymore at 45°. All I did was vacuum it and it cleaned right up.

Yeah, could be...that, and I run my draft at the low end, -0.04"

 

[STIHLY DAN]

well, this sucks.

Soon as I did the night load of mostly BL the house started to lose temp. At 6:45am, with outside temps -27°, the LP furnace kicked in. I really thought I had things rollin', and I did, until that BL load took me down.

I have done a total of 4 BL loads now and all four have resulted in lower than normal plenum temps. The first two were those which I stuffed the firebox full when leaving and setting the Kuuma on low and had those 20 hour burn times. Thought it was weird I was getting such low plenum temps throughout the whole burn. Then the night before last the same thing. It wasn't as cold as last night outside (-16° ) but the house started out at 76° and fell to 72° by morning. The oak loads during the day was able to bring the house temp back up. Then last night I had it maintaining 72°/73° with it being -26° outside and as soon as I loaded the BL for the night load the house temp started to trend down, 0.1° at a time, until it hit 68° and the LP thermostat called for heat.....6 3/4 hours after the night load. I have a digital temp gauge which display's house temps in 0.1° increments, very handy for being able to monitor temp trends.

Plenum temps on oak, when things are rollin and when I was able to maintain house temp, have been right around the 122°-124° area throughout the burn. Plenum temps with black locust (the last two over night loads) have only been 120-122° throughout the burn. Seeing the blower is speed controlled, this also means less volume of air as well.

I also found numerous threads online about other seeing similar results when not mixing it with other hardwoods.

https://www.hearth.com/talk/threads/burning-locust.102705/

Have any of you had similar results burning just BL?

YES. especially with hickory.. The densest woods have a longer burn time but don't burn as hot. Like pine is the exact opposite.

 

[STIHLY DAN]

Like with most HVAC guys, he is not too keen on wood heat. I don't know if he sees it as threat or what.

This Hvac guy loves it. But I hate that I am out fixing fossil fuel units when it is really cold, instead of relaxing and enjoying my warm, wood heat house..

 

[JRHAWK9]

The nice thing about monitoring various temps as some of us do is the fact that we KNOW what temps are normal and are to be expected. If and when we see any deviation from this norm it raises a flag. Case in point, I started to notice my flue temps were higher than normal and my plenum temps were lower than normal. Told me right away my HX needed a cleaning. IMO, without monitoring certain temps you are running blind.

 

[NoobTube]

Log cabin style with 23.5' tall 12/12 pitch roof. ~1,300SF main, ~1,300SF basement and an additional ~500SF loft. Have ~32,000CF of air space though due to the tall ceilings and no attic space. So equivalent airspace to heating a rectangle building with a 32'x42' footprint with almost 24' tall walls........or a 2 story home w/ 8' walls totaling ~4,000SF including the basement.

The basement is heated just from radiant heat off the Kuuma. The furnace area (~1/4 of the basement) stays roughly the same temp as the rest of the house. The other part of the basement, which is walled off and only has an open doorway joining the two areas, stays 4-5° cooler or so.

I burn, on average, 16,000 lbs of wood in a heating season. Convert that to whatever species suits your fancy.

Wow. Thats pretty awesome. I tried to heat full-time with my insert in my 2100sqft colonial and i went through 3 cords already this year, likely going to need another.

I don't even heat my basement, but my set up would have been pretty optimal for a Kuuma. I have ducts from my heat pump running through the basement and supplying the first floor. I imagine it would have heated my second floor pretty well too.

Its like that Cher song... 'If I could turn back time'...

 

[Case1030]

How often are you guys cleaning the HX on your Kuumas?

 

[brenndatomu]

How often are you guys cleaning the HX on your Kuumas?

I'm guessing I'll wait 'til spring for the next one...but I'll do it as needed I suppose...as JR said, when the normal flue temps go up, and the normal plenum temp goes down, its time.

 

[JRHAWK9]

Wow. Thats pretty awesome. I tried to heat full-time with my insert in my 2100sqft colonial and i went through 3 cords already this year, likely going to need another.

I don't even heat my basement, but my set up would have been pretty optimal for a Kuuma. I have ducts from my heat pump running through the basement and supplying the first floor. I imagine it would have heated my second floor pretty well too.

Its like that Cher song... 'If I could turn back time'...

I originally was looking at replacing our conventional fireplace with an insert of some kind. If the quotes I received would have been about half of what they were, we probably would have gone that route. Back then I didn't even know about wood furnaces and was set on just simply getting something more efficient than what we had. Man, sure glad we didn't go that route. I know for a fact a single point source of heat would not have done a good job in heating our place.

How often are you guys cleaning the HX on your Kuumas?

This is the very time time I've cleaned it during a heating season. The previous 4 years I just cleaned it once in fall before I fired it up for the year.

 

[Mrpelletburner]

I have had a OAK attached to my BD since the very first fire this fall and wanted to see how things looked after being sent ice cold air from this last cold snap.

Can you post photos of your OAK setup?

 

[JRHAWK9]

Can you post photos of your OAK setup?

If you look around at my posts I think I posted pics a couple times.