Woodstock Hybrid Performance

[Chris1927]

Does anyone out there have experience with the Woodstock Hybrid Stoves? I bought an Absolute Steel Hybrid. This is my second season with it. Overall, I am very happy with it. I have a 3200 square foot house, open concept, post and beam with structural insulated panels. They say it heats up to 1800 square feet. I am able to heat the whole house and keep it at 68-70 and above in temps that are upper teens during the day and say 10 at night? Maybe even in a little colder temps? If the temps fall below that, the stove starts to fall behind. I can't complain about that.

Anyway, the company claims that I should be getting 250 to 300 degrees on the stove pipe and 500 to 550 or higher on the top of the stove, that I should be getting spreads that are 200, 250, maybe 300 degrees? I generally get a pipe temp that eventually climbs to 350 and stove top temps of 500-550 when I restart from a hot bed of coals and, when the pipe temp reaches about 300, shut the damper to 1.5 and engage the cat. It doesn't seem to be performing optimally the way they say it should. I've checked for air leaks and I don't think I have them. The company also says that you shouldn't really be getting smoke coming out of the chimney when the cat is engaged. I think I always have smoke coming out the chimney. Any suggestions?

 

[Woody Stover]

Area heated ratings from Woodstock are pretty conservative, maybe based on cold climate and bad weatherization, so it doesn't surprise me that it's working well in your home even though it is larger.
My flue temp will drop once I have the bypass closed and the air cut but mine is a straight cat stove. If you are burning with secondary flame, maybe the flue temp will run higher until you cut the air low enough to go into straight cat mode.
What kind of wood are you burning, and how long was it split and stacked in the wind? Do you have a moisture meter? If you have to use a higher air setting because your fuel isn't optimally dry, you may be sending more heat up the flue than you would if your wood was 20% or less moisture content and the stove top won't get as hot, so in that case the stovetop-to-flue temp spread would be less.
It's possible that what you are seeing out of the stack is steam, not smoke. Steam looks lighter in color and acts lighter in weight, i.e. it will be more swirly and wispy. If the humidity is low outside, steam will often disappear within 10' of the stack whereas smoke will carry further before it disappates. Steam may persist for several hours into the burn.
Sometimes when the wind is right, the exhaust may be blown down to where you can smell it. If what you smell has a creosote smell, it may just be some creo burning off inside the stove with the initial high temp on a new load. If it smells like actual wood smoke, then it may indeed be. Smoke will be apparent early in the burn but should be gone once the re-burn of the stove is working well and you have cut the air

 

[Chris1927]

When I reload the stove on a strong bed of coals, when the pipe temp gets to about 300, I cut the draft down to 1.5 and engage the cat. I guess that's a little over 1/3 open. That's going by the instructions in the stove manual for a low or overnight burn. But I am pretty much always burning the stove with secondary flames when I do this. It doesn't usually go into straight cat mode. I guess I am a little paranoid about going into cat mode because I used to sometimes get strong back puffing, but that was mostly last year and I was using wood that was not optimally dry. Woodstock says that this stronger back puffing is okay and normal as long as there's no smoke leaking out of the stove. Do people think I should be cutting the draft back more than what I currently do when the pipe temp hits 300 so it will cycle into cat mode, then eventually go into secondary burn mode?

I do not have a moisture meter, but I am eventually going to get one. I am fairly confident that the wood I am burning is dry, but maybe I'm wrong.It is mostly maple with some ash and birch mixed in. The property was logged a few years ago and the logs have been sitting in the woods for a while. I have been selectively picking these species for this burning season because they are drier. I split and stacked the wood last fall, spring, and summer, but the wood seems dry. It makes the noise you want it to make when you drop it on the basement floor. There's a lot of oak out there, and I have been working on getting ahead of my wood pile, splitting and stacking this for future seasons.

It very well may be steam that I see coming off the stack. Initially, like you said, it's probably smoke, but it eventually transitions to what you describe as steam. I guess wispy and disappears within 10 feet of the stack.

 

[Joyboy]

I’m a little confused about what exactly you’re having problems with. Are your burn times not good? Sounds like it’s putting out enough heat.

Wood moisture is going to be 90 percent of most people’s problems. I’m new to dry wood religion as they call it. What I used to call dry wasn’t. I still burn some not so dry wood but can tell a huge difference in it. On higher moisture wood I have to give it way more air than normal to get to say 450 stovetop. Same amount of dry wood will go to 650 and then you’re throttling it back. Dry wood is more heat and longer burn times and less smoke.

Moisture meter is key to begin with. Once you start testing pieces you quickly get a baseline in your mind and quit using it as much later. But without it it is hard to tell where you are to start with.

I have the progress and close the air all the way for less heat or overnight burns. Sounds like the absolute has more fine air control. I think you will have to experiment with how far down you can go. Every stove and setup is different on where the low end is. Dryer wood will act very different than wet, which is where the meter comes in handy.

Best of luck!

 

[Chris1927]

Thanks. I'm not having problems per say. Like I said, I'm very happy with what I get out of this stove overall. I am just trying to learn more than I know now and I'm trying to learn the finer points of operating this stove so that I can get more optimal performance.

Most likely, what I think is dry wood is not optimally dry wood still. I will have to pick up a moisture meter. Last year, I bought a couple of bundles of kiln dried wood from the hardware store and tried that, but it didn't seem to make a difference. I will try doing that again and see if I get different results.

This morning, I rekindled the stove at about 7:00 and loaded it up. Just before the pipe temp reached 300, I cut the air way back from what I normally would (0.5 which is like 1/8 open). The stove eventually went black (cat mode) but it took a little while. The temp on the top of the stove stayed at 375 and the pipe at 250 for quite a while (i would think the stove top temp would climb at this point because the cat should be working and generating heat). Then, the secondary flames eventually kicked in and the temps peaked at 450 stove top and 300 pipe. Then at about 10:00, the secondary flames quit and the temps started to go down. Right now it's 10:45. The secondary flames started back up again and the temps are 340 stove top and 220 pipe.

Joyboy. What temperatures do you get on your stove pipe?

 

[Joyboy]

Thanks. I'm not having problems per say. Like I said, I'm very happy with what I get out of this stove overall. I am just trying to learn more than I know now and I'm trying to learn the finer points of operating this stove so that I can get more optimal performance.

Most likely, what I think is dry wood is not optimally dry wood still. I will have to pick up a moisture meter. Last year, I bought a couple of bundles of kiln dried wood from the hardware store and tried that, but it didn't seem to make a difference. I will try doing that again and see if I get different results.

This morning, I rekindled the stove at about 7:00 and loaded it up. Just before the pipe temp reached 300, I cut the air way back from what I normally would (0.5 which is like 1/8 open). The stove eventually went black (cat mode) but it took a little while. The temp on the top of the stove stayed at 375 and the pipe at 250 for quite a while (i would think the stove top temp would climb at this point because the cat should be working and generating heat). Then, the secondary flames eventually kicked in and the temps peaked at 450 stove top and 300 pipe. Then at about 10:00, the secondary flames quit and the temps started to go down. Right now it's 10:45. The secondary flames started back up again and the temps are 340 stove top and 220 pipe.

Joyboy. What temperatures do you get on your stove pipe?

Right now I’m about 470 stovetop and 305 stove pipe. This is with some air and some secondaries. Seems close to what you have. Those temps seem fine to me. Hopefully someone with a ideal or absolute will see this and chime in.

I haven’t really tracked where the temps are in correlation to each other on the progress. Have you cleaned the cat recently? The cat will only get as hot as the amount of smoke/air that you give it.

 

[Chris1927]

Right now I’m about 470 stovetop and 305 stove pipe. This is with some air and some secondaries. Seems close to what you have. Those temps seem fine to me. Hopefully someone with a ideal or absolute will see this and chime in.

I haven’t really tracked where the temps are in correlation to each other on the progress. Have you cleaned the cat recently? The cat will only get as hot as the amount of smoke/air that you give it.

Thanks. I vacuumed the cat on Christmas Eve. It is do for a cleaning very soon with distilled water and vinegar solution. Sounds like I am maybe getting the temps I should be getting. I'll try burning kiln dried wood from the hardware store anyway to see if there's a difference.

What type of moisture meter do people recommend me looking for?

 

[Joyboy]

I picked a cheap one up from amazon. It’s nothing special but does the job. Not sure what everyone else has.