Different Stove temps - Different weather

[harmerd]

I am curious what other people's experiences are with the temp drops outside. Last two nights were low 20's down to high teens. In the 30's plus I have to damper down to about 1/3 primary to hold the stove at 500-550, which its in full secondary, etc. When the temp was below 20 I was dampering at 50-55% to achieve the 500 degree hover. I don't suspect any drafting issues and I get "smokeless" burn out the stack. The only fan I use is regularly is a box fan blowing into the room from the other areas and sometimes the ceiling fan.(room is a cathedral open to the next room 800 sq ft total). I know the fans will lower the stove temp. Is the colder air in the house, with it 20ish outside, dropping my temp back requiring more air. Jotul Castine, and my glass is clear!.

My concern is the last load of the night. 1/3 damper was riding the 500 temp.....but if I leave it at half I could I get 575ish, which would make me uncomfortable. I end up with all most complete ash in the morning, may a handful of charcoal. Jotul says 400-600 is operating temp, glowing red is over firing, so I am right in the middle.


D

 

[begreen]

What you are experiencing is increased draft due to the increased temperature differential between outdoors and indoors. This is a good thing. Normally you'll want to be cranking out the heat when it gets colder.

FWIW, the Castine can go all day long with a 650 stove top temp. It won't start glowing until it's over 900. At about 750 degrees you will smell the dust burning off the hot cast iron. 600 degrees is a nice cruising temp that is well within the safety range for the stove as long as it meets or exceeds the recommended installation clearances.

 

[harmerd]

So more imbalance more draw. But I am opening the damper for more air to get the fire going for more temp. So the heat is being drawn up the stack? Do I have this correct. My wood is mixed, mostly oak, and dry.

I can't get the Castine to burn for a long period, meaning 6 hours, at a good temp. If I bulk load her, with medium splits, after she has coals and after she has run at 450-500 she seems to take a long time to get going. Since I am not burning 24/7, just the evening to bedtime, I have been running 4-7 2in to 4inch splits and running hot fires for shorter times. The last fire, with tons of coals, I get going and damper for the night. This is why I was trying to figure out the temp issue.

D

 

[DiscoInferno]

So your draft seems to be getting worse in the cold, not better? This goes against the conventional wisdom. Yet I see the same at times, and I don't think it ever gets any better in the cold. But then I do have an air-cooled chimney in an uninsulated external chase.

 

[JimWalshin845]

So more imbalance more draw.
D

Yep... look at the top of your chimney on a warmer day and then on a real cold day with little wind. You will see a huge differnce how the exhaust exits the flue.

 

[jgoodnow]

Maybe this has less to do with draft and more to do with heat production and consumption. The heat loss from your house is going to be higher when it's colder outside, so the way I see it you have no choice but to burn more fuel per unit time in order to maintain a given stove temp and room temp. This may require opening the damper more despite the increased draft due to the higher temperature differential. I'm speculating here.

 

[Jimbob]

Wind speed and direction have at least as much of an effect on draft as temperature. One of those factors could be giving you the lower draft.
Wood size and dryness are 2 other factors determining stove temp.

 

[harmerd]

Maybe this has less to do with draft and more to do with heat production and consumption. The heat loss from your house is going to be higher when it's colder outside, so the way I see it you have no choice but to burn more fuel per unit time in order to maintain a given stove temp and room temp. This may require opening the damper more despite the increased draft due to the higher temperature differential. I'm speculating here.

I keep leaning towards THERM's comment since I have read in the Forum and have seen in my experience how people have lowered stove temps with their fans, sometimes to get the stove down from over-firing. When the fan comes on and the cooler room air hits it the temp can drop 50-100 degrees in a short time.

The only drafting issues I have seen are when the dryer is on, a Propane model, and the stove is just getting started or is on reload(300ish) and its minor. If the dryer is on and I am in the 500s there is are no issues with the draft. Of course if your teenager leaves on both bathroom exhaust fans.............but I watch that anyway regardless of time of year.

I will experiment more with different wood species since I have them. As one person said something about the wood. I could have hit a slightly damper area of my tarped wood pile/lower on the stacking/etc.

D

 

[philaphire]

So more imbalance more draw. But I am opening the damper for more air to get the fire going for more temp. So the heat is being drawn up the stack? Do I have this correct. My wood is mixed, mostly oak, and dry.

I can't get the Castine to burn for a long period, meaning 6 hours, at a good temp. If I bulk load her, with medium splits, after she has coals and after she has run at 450-500 she seems to take a long time to get going. Since I am not burning 24/7, just the evening to bedtime, I have been running 4-7 2in to 4inch splits and running hot fires for shorter times. The last fire, with tons of coals, I get going and damper for the night. This is why I was trying to figure out the temp issue.

D

As a fellow medium stove owner, I think we need to have realistic expectations on what a long or overnight burn means. Manufacturers seem to think that as long as there are hot coals the stove is burning. Sure, after 8 hours with primary air cut off I have hot coals, but also a cold house with my furnace kicking on. So, I know that on a cold night, the stove won't cut it, and that's okay - the goal for me is to have enough coals in the morning to fire it back up again quickly. One thing I've tried to figure out is to maximize when to reload before bed. That is, get the cycle going so that you're shutting down the air on a reload at about the same exact time you're about to turn the lights out. That way when you get up 6-8 hours later, you should have decent coals to battle the morning chill.

 

[harmerd]

[/quote]

As a fellow medium stove owner, I think we need to have realistic expectations on what a long or overnight burn means. Manufacturers seem to think that as long as there are hot coals the stove is burning. Sure, after 8 hours with primary air cut off I have hot coals, but also a cold house with my furnace kicking on. So, I know that on a cold night, the stove won't cut it, and that's okay - the goal for me is to have enough coals in the morning to fire it back up again quickly. One thing I've tried to figure out is to maximize when to reload before bed. That is, get the cycle going so that you're shutting down the air on a reload at about the same exact time you're about to turn the lights out. That way when you get up 6-8 hours later, you should have decent coals to battle the morning chill.[/quote]

After reading 1000 posts over the months I have figured this out also. Expectations being realistic are everything. Warnings about creosote/fires are taken seriously. Sizing and stove location important. The Medium Castine works thusfar as my stove shop told me for the info I gave them. 1-2 hours burn = 1 room warm, 2-4 = two rooms, 4-6 = three rooms(900sqft.), 6 hr plus 1500sqft warm......then the stove area is 75....too hot for me....thus the Castine was sized correctly IMO.