Flue damper and stove air control, Jotul Oslo

[My Oslo heats my home]

My question is directed at the night time burn. I have seen a few posts recently where some stove owners are running a nearly closed flue damper and their air control choked to achieve a hot night time burn with long term results. Since the install of my Oslo 3 years ago I have only contolled the air intake to achieve a warm home during 'awake' hours. At night I load the firebox and choke out the air. The stove will, at best, keep maybe 275-325 during the first 6 or so hours, and I do get a small bed a of coals in the morning for a good startup. So, all that said, what options can I look at for a hotter, longer burn at night? Thanks...

 

[Green Energy]

My question is directed at the night time burn. I have seen a few posts recently where some stove owners are running a nearly closed flue damper and their air control choked to achieve a hot night time burn with long term results. Since the install of my Oslo 3 years ago I have only contolled the air intake to achieve a warm home during 'awake' hours. At night I load the firebox and choke out the air. The stove will, at best, keep maybe 275-325 during the first 6 or so hours, and I do get a small bed a of coals in the morning for a good startup. So, all that said, what options can I look at for a hotter, longer burn at night? Thanks...

I find that the Oslo is not going to provide a hot burn after 6 hours or so. It is still radiating heat, but probably 20-30% of the output, after 6 hours, it had at maximum output. Although I am getting 500 - 600 F, sometimes 600 - 650, for the first 2-3 hours, temp then drops during the coaling stage, 400 ... 300 after 4 to 5 hours. For good coals after 8 - 10 hours, I find that a good round, 4-6", in the back of the stove helps, stove top is only 200 - 250 F though at 8-10 hours.

I can't use a flue damper as I am venting out the rear and into a T, then up a chimney liner. But I do have a pipe connected to the air-intake, where the OAK connects. Sometimes when I do a hot reload, and fill it up for the night, and hit 650 F, I will put a stove glove over the piped air intake so not to go higher. It doesn't completely shut off the air as it is not air tight. But it does moderate the available air. I am not sure that it really extends the burn time that significantly.

 

[snowtime]

I do not have your stove but it sounds like your not getting much heat. On a full load my stove will go to 700+ and stay there for 4 hours before slowly cooling for the next 5 hours and thats with closing the air all the way immediately. Maybe you need to load it up for the night when the stove is running at 400+ and your letting it get too cool. I know its recommended to burn the "cycle" but heat is what we want the most. A pipe damper will help on longer burns but I am not sure how much it will help on a stove thats not reaching a decent heat level.
I think more experimentation with loading times {by that i mean load temp} and air levels is in order.

 

[shawneyboy]

You say you load up the stove and choke out the air. Question are you doing just that ? Load it and "choke" it right away ? If so perhaps you are making a smoldering mess ? Just wondering.

 

[My Oslo heats my home]

I did a test "night' burn this morning, after doing a normal morning burn cycle. I had a nice bed of coals, maybe 2 inches total, opened up the air and got the stove to about 400, then loaded a full load. Ran the load fully open for about 10 mins then closed it down. It's 2:20 pm and I still have a nice glow at 350 deg with the air choked, it's been approx. 6 hrs. I might give this a twist tonight and see if I can offer up a round as mentioned. Thanks for the advice...

 

[NH_Wood]

I close the pipe damper (1/2 to just cracked) as the last set in nearly all my burns. Lots of folks would not be able to do this due to weaker draft (my draft is very strong). Sounds like you don't need the pipe damper at all, and that by using it you are burning a fairly cool fire and probably getting a good deal of creosote. But...sounds like you figured out your problem. Get a good, hot fire during the early burn cycle, then slowly back down the air until the secondaries are well maintained at the lowest air level. I've read of folks loading up the stove for the overnight burn and immediately choking the primary air. Can't see this working well for any EPA stove - the load needs to get engulfed in flame and well charred before the primary air is lowered. I'm just now getting to know the best times for beginning the cycle of lowering the air - takes a while to learn these things when first starting out. Good luck. Cheers!

 

[My Oslo heats my home]

I close the pipe damper (1/2 to just cracked) as the last set in nearly all my burns. Lots of folks would not be able to do this due to weaker draft (my draft is very strong). Sounds like you don't need the pipe damper at all, and that by using it you are burning a fairly cool fire and probably getting a good deal of creosote. But...sounds like you figured out your problem. Get a good, hot fire during the early burn cycle, then slowly back down the air until the secondaries are well maintained at the lowest air level. I've read of folks loading up the stove for the overnight burn and immediately choking the primary air. Can't see this working well for any EPA stove - the load needs to get engulfed in flame and well charred before the primary air is lowered. I'm just now getting to know the best times for beginning the cycle of lowering the air - takes a while to learn these things when first starting out. Good luck. Cheers!

I'm rarely home in the evenings, so I have no time to do any experiments on the night burns. I'm on vacation this week and decided to try a few things out and pass them on to my wife so she can do them when I'm not here. So far so good on the tests today. Cheers to you too. and TY

 

[Shari]

Load it up. Bring it up to somewhere between 450-550. Shut air down 1/2. Let it sit for about 15 minutes and then lower to 1/4 open = "Doing the Two Step" with my Oslo.

 

[My Oslo heats my home]

Load it up. Bring it up to somewhere between 450-550. Shut air down 1/2. Let it sit for about 15 minutes and then lower to 1/4 open = "Doing the Two Step" with my Oslo.

What kind of results do you get from your "two step"? Burn duration? overnight temps?

 

[Shari]

Well, if the last load is around 11pm I've got around slightly less than 300 at 6:30am and normally enough coals to just toss in a couple of splits and get 'er going again. BTW Burning silver maple which isn't the greatest BTU's.

Details: 6" insulated SS liner, interior chimney, about 15' tall.

Shari

 

[ansehnlich1]

My stove burns completely different based on the wood used. If I pack my oslo with red oak seasoned 30 months she'll climb to 650, then I'll set it at half mast for a spell, then back it down to just a smidge open, she'll secondary like that for several hours, in the morning it's been no less than 71 degrees in the livingroom/stoveroom and the oslo has a 2 to 3 inch coal bed to re-fire with.

Now, if I put in real dry ash it won't behave as stated above. Not even close. However, If I use Cherry/Walnut that's seasoned a year or so, it'll take care of business similar to the oak but not leave near the coals in the morning.

If I use decent hickory and/or locust, she'll just behave wonderful, very much like the red oak load.

What kind of wood your burnin' anyhow?

 

[webby3650]

I do not have your stove but it sounds like your not getting much heat. On a full load my stove will go to 700+ and stay there for 4 hours before slowly cooling for the next 5 hours and thats with closing the air all the way immediately. Maybe you need to load it up for the night when the stove is running at 400+ and your letting it get too cool. I know its recommended to burn the "cycle" but heat is what we want the most. A pipe damper will help on longer burns but I am not sure how much it will help on a stove thats not reaching a decent heat level.
I think more experimentation with loading times {by that i mean load temp} and air levels is in order.

This is exactly how my Oslo operates! I recommend the same experimenting

 

[My Oslo heats my home]

Anse, I'm burning red & white oak and maple this season. Webby, I'm going with some of Shari's hints on overnight burns. I'm going to make some adjustments tonight and experiment with some large rounds on the 'overnight load'.