Timing bedtime with a cat stove

[Ashful]

With a cat stove (and maybe particularly a downdraft cat stove), it seems that feeding it a few splits at a time all evening, is not an efficient way to burn. It would appear that it is much better burning a decent size load, so you can get things up to temperature, engage the cat, and then dial the air for the burn time or temperature you desire. With feeding a few small splits at a time, you spend much time in bypass, and fiddling with going between bypass and cat burning.

This is all fine and good, but does make timing bedtime a challenge. If I just feed the stove a few small splits at a time, I can be ready to stuff the stove with the big overnight load just about any time. However, if I'm batch burning, particularly starting from a cold stove and house around 6pm each evening, it seems I need to size that first batch just right to get the house up to temperature (not too small), while still being ready to stuff in that last big load around 10pm (not too big). I've gotten this right a few times, but more often not, so I'm wondering how the rest of you cat stove burners handling this.

BK owners are automatically disqualified. We already know you only need to load once per day, no need to re-state that.

 

[clemsonfor]

I have a large cat stove. If i am going from a cold house and start, i will get a kindling fire going then put a few splits on it and them may or may not go into CAT mode before the large load. If i do engage them its only a few pieces for a few hour burn and usually burned at a high rate to pump heat out and just to get a good hot burn on the cat to burn out stuff that i perceive to have settled on it as the last fire cooled and smoldered out. Anyway i will load sometimes a few hours before bed if need be or right at bedtime in enough time to engage the cat, but my stove will burn 8 hours on a pretty high burn rate and close to 24 hours on a low rate so my timing is not that critical this time of year? The species of wood also helps me control the temp output so i dont have to open windows.

I have however found that my stove does not like pine on a super low burn rate. Cat does not want to stay lit after a few hours i think due to lower heat , i assume?? Also just due to the nature of how pine does not coal up it seems the flame/smoulder of a low burn does not transfer between splits very well and i end up with half burned splits or splits that will just smolder all the next day. HW does not do this at the same burn rate so its a symptom of the pine?? I still use it but it works better at a high burn rate. Also its not a MC thing, my pine is actually less MC than most of my HW right now!!

 

[HollowHill]

Joful, this is an excellent question, one I am wrestling with as well. It always seems I am waiting with drooping eyelids for the coals to burn down enough that I can do the last reload, or I reload too early and wake up to a cooler house. So, I have no advice to offer, but will read this thread with avid interest.

 

[mellow]

Tonight I will light the stove after I get home from work (around 6pm). I load the wood N/S once I get a fire established so that I have coals running from the door to the back of the stove, then at 9pm I will load the rest of the wood E/W on top of those hot coals and let that get good and charred, then I close the damper and slowly dial down the air and the cat usually purs around 1000, it will climb up to around 1500-1700 later in the burn then come back down, when I come down in the morning around 8:30am it is usually right around 400-500 degrees on the cat probe.

 

[Jags]

I don't think this is unique to cat stoves. Same same for us tube guys. My trick is to have a few small (like 2-3" small) splits. This allows me to adjust the burn rate of my box. I can use them to consume a coal bed, increase the temp and burn rate to burn a load down, or to just cruise up to the point for an overnight load.

Oh - and for your cat guys, my method does not allow for the stove temp to dip below an active cat temp.

 

[Ashful]

Interesting point about species, clemsonfor. I have been burning a lot of softwoods mixed with walnut. I have miles of 1-year oak and even some weeks-old ash CSS'd everywhere (13 cords, by last count), but it won't be ready for at least another year. Having just moved and started with this last fall, I'm still struggling with seasoned wood supply.

 

[ddddddden]

. . .if I'm batch burning, particularly starting from a cold stove and house around 6pm each evening, it seems I need to size that first batch just right to get the house up to temperature (not too small), while still being ready to stuff in that last big load around 10pm (not too big). I've gotten this right a few times, but more often not, so I'm wondering how the rest of you cat stove burners handling this.

Yeah, that's pretty much the drill, for both cat and non-cat burners, AFAIK. Unless it's not that cold out and you're doing 12-hour reloads, you burn a small one dinner-->bedtime. I dunno 'bout sizing the load perfectly. Maybe err on the side of too much, and just do a "hot" reload if the batch hasn't finished before bedtime. . .probably still more efficient than adding pieces instead of doing a batch.

BK owners are automatically disqualified. . .

Disqualification of The BorgK is futile.

 

[mellow]

I keep an axe by my burning pile on the porch, just in case I need to cut down some pieces for smaller loads, also helps to have small ones to fill the gaps while loading the stove full for overnight burns.

 

[jharkin]

Yes, downdraft catalytic stoves area tricky beast. I especially struggled with this my first and second seasons, dealing with less than seasoned wood that took a long time to get going well and a drafty house that didn't hold heat well. I would typically load every 3 hours during the day and time my dinner load to be able to reload around 9 for bed. I would usually do the split counting method - figure one hour of burn time for each medium size (4-5in) split. I did the late load at 9pm because a full load of so-so wood takes a long time to get up to cat liftoff temp reliably. I would then watch it at least an hour after I got it into cat mode because those big loads would sometimes stall the cat and then suddenly take off and go nuclear much later.

I'm having a much better time now with a better sealed/ more controllable stove, truly dry wood, and a better insulated house that holds the heat longer. Except for warm shoulder days I typically run just a couple big loads each day. As long as the house is up to temp from daytime burning, I can do the night load anytime after 7pm or so and stretch it out till the morning reload. On really cold January nights the house might get a a little cool overnight, in which case I either let the gas heat kick on briefly or get the living room really hot (75+) before the night load goes in. On mild shoulder days I can get away with doing a partial load.

The tricky part I find is that the conditions/time to get a good cat liftoff appear to vary non-linearly with the size of the load. On a good coal bed starting from a warm stove I can get a half load to 500F griddle and light off the cat easily in 10 minutes or so. A full load can take more than twice as long and 500 is not hot enough for a reliable light off, sometimes I need to get the griddle up to 600+ on those big ones. Warming up a big load that long also requires turning the air control down to about half before going on bypass to avoid overheating the flue.

 

[jharkin]

Speaking of this topic, where is our friend Mr. BAR.... Maybe we can start a "masochists who heat antique homes with fussy downdraft catalytic stoves" clubs. With a special inner circle of pain for you stone house folks.


Probably wont get as much press as Mr. Overkill's cordwood club tho

 

[Ashful]

Great observations, Jeremy. I probably am getting my flue very warm on my way to cat light-off, as I don't have a flue temp probe to monitor... but with a new insulted stainless liner inside an already good masonry chimney, should I really be concerned about that?

It sounds like the answer to my woes is the answer to so many other... it will get better as my wood supply ages and improves. I find I can get some loads ready to engage and throttle back after only 30 minutes, others take over an hour. I've gotten pretty good at feeling the moisture content of a split, just by picking it up, but still haven't learned how many less than perfectly-seasoned splits I can mix in with the dry before the stove gets unhappy.

We should start a club, although BAR gives me the impresson that his is far more drafty than mine. The oldest and largest part of my house is still completely un-insulated, plaster applied directly to stone walls, and my heating bills are not that bad. My annual oil usage is only 1400 gallons, and the tax man claims I'm heating 5500 sq.ft.

 

[clemsonfor]

I just got a tube stove for the farm house. All i can say is the cat stove is way easier to run than it, and on less then ideal wood the cat eats the wood much better, from my observations. Sorry this is a bit off topic but kind of on, related to the CAT stove and less than ideal wood.

 

[charly]

I just load my Fireview around 5pm 3 pieces of wood and what ever room I have at 10pm, I throw in some more pieces.. Never seems like an issue.... If I have a lot of coals or some whole pieces of wood left, I just close the by pass that much sooner , even though the stove or cat temp is ready to go. I don't let the stove run me, I've learned to run the stove. I guess the Fireview just seems so forgiving and easy to run,, it's not an issue here.

 

[jharkin]

Great observations, Jeremy. I probably am getting my flue very warm on my way to cat light-off, as I don't have a flue temp probe to monitor... but with a new insulted stainless liner inside an already good masonry chimney, should I really be concerned about that?

Good question... To be honest I don't know if Ive ever overheated my flue... Ive got a second stove top thermometer that sits on the cast iron flue collar - at times heating big loads Ive seen this one go into the red zone over 500F (whereas usually it runs 150 or so cooler than the griddle). I'm guessing if its that hot at the exit the flue is pretty hot too. The other warning sign I watch for is the liner making a lot of pinging/creaking expansion noises.

I doubt you would have any issues with the brand new liner, im just being cautious.

We should start a club, although BAR gives me the impresson that his is far more drafty than mine. The oldest and largest part of my house is still completely un-insulated, plaster applied directly to stone walls, and my heating bills are not that bad. My annual oil usage is only 1400 gallons, and the tax man claims I'm heating 5500 sq.ft.

You'd kick me out of the club if I told you what my bills are... well heck... about 900 therms of gas and just over a cord last year, dhw included. But considering my house could probably fit in your living room, and I do have (some) insulation, your numbers are not too bad relatively.

You want to really get depressed go read the average home energy consumption thread in the green room.

 

[gmule]

I just load my Fireview around 5pm 3 pieces of wood and what ever room I have at 10pm, I throw in some more pieces.. Never seems like an issue.... If I have a lot of coals or some whole pieces of wood left, I just close the by pass that much sooner , even though the stove or cat temp is ready to go. I don't let the stove run me, I've learned to run the stove. I guess the Fireview just seems so forgiving and easy to run,, it's not an issue here.

This is what I usually do on my days off. Since I work a mid shift schedule I get home in the early hours of the AM So it is ready for a full load when I get home. With my work schedule I tend to have the opposite problem of timing when the fire should cool down other wise I have to open a window or get cooked out.

 

[rdust]

BK owners are automatically disqualified. We already know you only need to load once per day, no need to re-state that.

I just wanted to say that now that it's getting colder I'm doing two partial loads a day instead of one big load on most days.

I don't find reloads to take any amount of time. I loaded the stove at 7:42am and was out the door at 8:00am with a stove top just below 600 and beet red cat. When it's warm and I need to dial it down a little lower it may take another 10-15 minutes before I want to walk out the door. I think the problem has more to do with the advancements in cat technologies since your Jotul was made when comparing to manufactures like WS and BK. It seems the newer cat stove are a little easier to control/burn.

 

[Todd]

I don't get this batch burning teqniuque, why not just burn a two load 12 hour schedule or a 3 time per day 8 hour burn schedule with smaller loads? Is it not cold enough to go 24/7? Wouldn't just one big load in the morning or evening take the chill off til you can do a 24/7 schedule?

 

[Slow1]

With the FV I was able to do the "just start it and then load up to full at bedtime" approach. Sure, sometimes it was a bit of a hot load, but I could just cut the air down more and it was ok - never ran away from me. Mind you I would still try to time it right (the one split/hr or slightly less is a good guide). Generally speaking, I would far rather load on a large bed of coals than a tiny one/cold stove.

Now with the PH I really don't have enough experience to say what is my 'normal'. We had about a week that I was running a 12hr reload schedule - it was cold enough... almost. House got a bit warm actually. Right now I've been down to one start/day with the load size dependent on the forecast for the day.

I don't yet know if the 6pm load followed by a 10p bedtime load will be an issue for the PH - I haven't loaded on a very hot bed yet. I am a bit more concerned about smoke in the room from a partially burned load though as it seems that even with the bypass open the PH has a more complex path for the smoke to exit and thus I get a bit more smoke spillage - that could be the one bad thing about loading too soon. Then again, maybe if the flue is good and hot it won't be as much of an issue.

 

[Backwoods Savage]

After you've been at this game for a few years you'll do things without even giving it much thought at the time. You just do them. For sure in the late afternoon if the stove needs wood you put some in. How much? It all depends upon the outside weather and what the inside temperature is. The end result is that you want to be warm so always keep that in mind and don't get carried away with theories. If you need some heat, give the stove some wood. But depending upon when youre bedtime is, that probably won't be a full load.

My biggest problem this fall has been that I suddenly get sleepy and want to go to bed then remember I have to put wood in the stove. Fortunately for us it is a matter of 3 or 4 splits so it is not a big job for sure. Last night I put in 4 splits. When I got up this morning it was nice and warm and a huge bed of coals. I put in 3 splits and that lasted until just short time ago. That wood will be burned down quite well by bedtime then we'll put in 4 splits again tonight.

Some folks tend to overthink these things. Just do it and move on.

 

[Ashful]

It's been unusually warm and rainy here, Todd. Also, I don't see much point in keeping the stove going during the day, when the house sits empty 10 hours. Seems like I'd waste a lot of wood over the course of a winter doing that.

Slow1, I think I'll try going bigger on my dinnertime reload, and then just loading hot at bedtime. So many have posted problems with their stoves going nuclear when reloading on a large coal bed, that I've just always avoided it / never tried it myself.

 

[Slow1]

I'd try the hot load the the first time when you can stick around and watch it - better to monitor until you know how it behaves.

 

[mfglickman]

I dream of being one of the people who can warm a room on 3 splits in my Fireview, but I think I'm a more likely candidate for the drafty antique house club.

I stuff it pretty full between 9 and 10, and watch it get to its peak or close before I go to bed.

 

[Backwoods Savage]

I don't watch it get to peak at all. Put the wood in, wait a few minutes, engage the cat and go to bed. End of story.

 

[mfglickman]

I don't watch it get to peak at all. Put the wood in, wait a few minutes, engage the cat and go to bed. End of story.

This is the difference between 50 years and 1 year. I don't know when I'll shift bu for now, I needto know or I won't go to sleep.

 

[BrowningBAR]

For 24/7 burning I load stoves at 8:30-9:30 am. Reload stove with a smaller load 5:00-7:00 pm. Load stove at 11:00 pm. Repeat. Depending upon the outside temps depends upon the number of stove that participate.

I'm not sure what batch burning is.

On mild weather I run the Defiant and the 30 with smaller loads of 2-4 splits. Both stoves run fine this way and can manage 5-7 hours of heat. With a good bed of coals, the Defiant spends very little time with the bypass open.