How much to load in stove?

[Riverside_eng]

I had a Enviro Cabello 1200 installed this summer.

I have been cautiously running it to get a hang of it but keep figuring I could be doing better.

Though I know I have a few things going against me.
1) Insert vs freestanding stove. The blower can only move so much of the heat out of the enclosure to the room.
2) Starting it from cold each evening and in the morning on weekends. So carrying that thermal intertia at startup.
3) Have been worried about burning through too much too early in the season. I have 1 cord of dry wood stacked (moisture meter checked all splits I was cutting to kindling were 16-18% inside at initial split) plus 2 pallets of wood bricks.

My stove seems to draft well (or very well) as it is rarely a challenge to start (door closed and air open until everything is going), and even with damper all the way down the fire keeps going though is showing some reaction to reduced air. Only issue was some wet wood because I was slow to throw tarps over the stack outside in the fall.

With that said I seem to be getting about 2.5-3 hr a load. The amount of heat I get is expectedly somewhat propprional to how I load it. 3 2lb bricks and filling with a variety of sized splits can get fairly toasty but if I just throw in 4 bricks (like this morning) I don't see any noticable change in room temp but it is throwing some medium heat from the blower and radiating from the door.

[Edit: To be clear on this morning, it is 16F out and the oil heat didn't come on while the thermostat says it hovered between 61 and 62 for 2 hours, so it was putting out SOME heat to keep the house temp steady]

So how much do people end up loading up their stove normally? When I put in 8lb worth of wood bricks is that just the equivalent of throwing a pinch of spice into a pot of chili where it is expected to not get much of a noticable result? If I load it up should I expect more burn time because there is less oxygen per cubic volume of wood?

 

[jatoxico]

IMO It's good you're moving a little cautiously and gaining a feel for the stove before going all in. I don't see anywhere that you gave a stove top temp. I'm reluctant to tell people to pack it full and let it rip until they know they can control the stove.

Get a thermometer and take some temp readings over a couple burns to assure yourself you can control the stove. A full packed load (esp bricks) in a stove with little or no control is a recipe for overfire. Even in a controllable stove you need to turn down air enough and at the right times (temp) to avoid excessive temps and gain max burn times.

 

[begreen]

The key to getting a long burn out of compressed bricks is to pack them tightly so that there is no air gap between them. Then stack the next layer at 90º to the bottom layer, again with no gaps.
http://originalbiobricks.com/lighting

 

[weatherguy]

Let us know your stove top temps. At night I load all I can fit into the stove but I'm familiar with the stove and can control it, it takes a little while to get to know your stove.

 

[shortys7777]

I have the kodiak 1200 and its also my first year. How big is your house? It should be getting way above 62 degrees. I have a 1,500sq ft ranch and the back bedroom gets to 70-72. I have been learning new things. The hotter I burn the cleaner the glass stays. I tighter I load and fill it up the longer burn times I get. The longer I keep it burning the most constant temp I get throughout the house. The fans creates a convection and I can feel the cool air coming toward the stove on the ground. I bought an infrared heat gun and measure the temp at the flue collar. If I only put 4 or 5 logs I get 3-4 hours burn time but when I fully load it I can get coals for a relight 8-9 hrs. Your conditions are similar to mine. (I grew up in Andover btw)

 

[mstoelton]

A note of caution with the bricks. Bricks can expand dramatically when burned. This expansion can damage your insert. Be cautious about completely filling (packing) the stove with bricks without leaving some gap at the top.

Also you did not mention you entire set-up so I will suggest some improvements that could help you set-up if you have not already completed these.

The number one biggest improvement that inserts can have is a block-off plate in the chimney above the stove. these can be installed while the stove is in place if necessary. Essentially a block-off plate keeps the heat from climbing up into the chimney and being dissipated into the chimney rather than staying down in the house. This is especially important if you have an external chimney. There are several how to's on this site on the subject of constructing a block-off plate for a chimney.

Second, an insulated liner with a top cap also holds the heat in the liner and will reduce risks for creosote build-up and reduce the risks of a chimney fire (insulation also makes clean-out of the liner easier, because it will tend to hold the heat better and reduce the risk of the sticky tarry type of creosote).

 

[Riverside_eng]

IMO It's good you're moving a little cautiously and gaining a feel for the stove before going all in. I don't see anywhere that you gave a stove top temp. I'm reluctant to tell people to pack it full and let it rip until they know they can control the stove.

Get a thermometer and take some temp readings over a couple burns to assure yourself you can control the stove. A full packed load (esp bricks) in a stove with little or no control is a recipe for overfire. Even in a controllable stove you need to turn down air enough and at the right times (temp) to avoid excessive temps and gain max burn times.

I have an infrared laser thermometer and used it to check some during burns but never kept track. Where is it best to measure the temperature, because the surround blocks the connection to the liner and I figured measuring through the glass of the door was not a repeatable item and I would also need to get an equivalent point in the fire each time as depending on how I build it different parts will be slightly different temperatures.

The key to getting a long burn out of compressed bricks is to pack them tightly so that there is no air gap between them. Then stack the next layer at 90º to the bottom layer, again with no gaps.
http://originalbiobricks.com/lighting

Thank you for the link!

Let us know your stove top temps. At night I load all I can fit into the stove but I'm familiar with the stove and can control it, it takes a little while to get to know your stove.

I know, and I figure its always possible to add a little more the next time rather than wish I could take some out when it is a burning inferno.

I have the kodiak 1200 and its also my first year. How big is your house? It should be getting way above 62 degrees. I have a 1,500sq ft ranch and the back bedroom gets to 70-72. I have been learning new things. The hotter I burn the cleaner the glass stays. I tighter I load and fill it up the longer burn times I get. The longer I keep it burning the most constant temp I get throughout the house. The fans creates a convection and I can feel the cool air coming toward the stove on the ground. I bought an infrared heat gun and measure the temp at the flue collar. If I only put 4 or 5 logs I get 3-4 hours burn time but when I fully load it I can get coals for a relight 8-9 hrs. Your conditions are similar to mine. (I grew up in Andover btw)

How do you measure the flue collar? Any tips since I assume it shares some similar construction.

Also how much are you loading into the Kodiak? My main thought is that I might just not be loading much in. Volumetrically the box is pretty empty with 4 bricks, but it is compressed and at a lower moisture content.

If I load with 3 bricks and 2-3 splits I get similar times, though it is not filling the box by any means. That throws more heat, but maybe I am just being a miser with my limited supply.

House is a 2 story 1800 sqft house, built in 1911. Previous owner got insulation blown into the walls and the windows are cheap contractor grade but about 4 years old.

I will have to try again this evening but fill the rest of the box with splits on top of the bricks to see the relative heat result.

A note of caution with the bricks. Bricks can expand dramatically when burned. This expansion can damage your insert. Be cautious about completely filling (packing) the stove with bricks without leaving some gap at the top.

Also you did not mention you entire set-up so I will suggest some improvements that could help you set-up if you have not already completed these.

The number one biggest improvement that inserts can have is a block-off plate in the chimney above the stove. these can be installed while the stove is in place if necessary. Essentially a block-off plate keeps the heat from climbing up into the chimney and being dissipated into the chimney rather than staying down in the house. This is especially important if you have an external chimney. There are several how to's on this site on the subject of constructing a block-off plate for a chimney.

Second, an insulated liner with a top cap also holds the heat in the liner and will reduce risks for creosote build-up and reduce the risks of a chimney fire (insulation also makes clean-out of the liner easier, because it will tend to hold the heat better and reduce the risk of the sticky tarry type of creosote).

I have been fairly conservative on how much I am putting in given both expansion concern but also not going in just filling up the box to start as I would have no idea how much heat it would be throwing.

Chimney is an external chimney, brick, and block off plate had not been discussed with the installer and didn't occur to me until afterwards. I will have to look into that in the future.

 

[shortys7777]

Is the liner inside your chimney insulated? If not it should be. I called a few places in MA, NH, RI and quite a few said no need for insulated liner. I have been doing my research on here for some time and simply told those stores/installers no thanks. I bought one of Rockford and insulation package. I measure my temps under the top where the air is blown out and point it at the collar where the liner is screwed in with sheet metal screws. I did the install my self. As for block off plate I shoved a bunch of safe and sound insulation and cut the old fireplace damper to fit around the liner. Not perfect but I bet it keeps most heat in. May do a more permanent fix next year. If I am over night burning I'll fill north to south packing tightly on a good base almost to the secondary bars depending on how the wood fits without touching the bars. If starting cold I put some logs on the base and build a nice fire on top of them with kindling and smaller split pieces to get it up to a temp where the blower turns on then fill her up after that.

 

[Riverside_eng]

Is the liner inside your chimney insulated? If not it should be. I called a few places in MA, NH, RI and quite a few said no need for insulated liner. I have been doing my research on here for some time and simply told those stores/installers no thanks. I bought one of Rockford and insulation package. I measure my temps under the top where the air is blown out and point it at the collar where the liner is screwed in with sheet metal screws. I did the install my self. As for block off plate I shoved a bunch of safe and sound insulation and cut the old fireplace damper to fit around the liner. Not perfect but I bet it keeps most heat in. May do a more permanent fix next year. If I am over night burning I'll fill north to south packing tightly on a good base almost to the secondary bars depending on how the wood fits without touching the bars. If starting cold I put some logs on the base and build a nice fire on top of them with kindling and smaller split pieces to get it up to a temp where the blower turns on then fill her up after that.

Given that I don't know for certain, assume uninsulated.

Lit this off about 15-20 mins ago. Getting hot in front.

Temp at liner connector says 500f? (Kept retrying and getting different numbers but all trending up)

 

[jatoxico]

Where is it best to measure the temperature,

I have a flush insert and have a thermometer on the stove top in the vent about 4" back. I use a flashlight to see it if I need to and also have an IR that I use to shoot the flue collar. Don't do that much anymore but used it a lot at first.

The absolute temp is less important that being able to check for big temp swings and the thermometer, even if off, gives you a consistent reference point. Normal peak for me is 600-650. Cruise is 550ish depending.

The danger zone IMO starts as you approach 750+. If you can't slow it down from there using air control then I'd consider that a problem. One basic rule is no glowing, not the top, not the collar.

 

[Riverside_eng]

I have a flush insert and have a thermometer on the stove top in the vent about 4" back. I use a flashlight to see it if I need to and also have an IR that I use to shoot the flue collar. Don't do that much anymore but used it a lot at first.

The absolute temp is less important that being able to check for big temp swings and the thermometer, even if off, gives you a consistent reference point. Normal peak for me is 600-650. Cruise is 550ish depending.

The danger zone IMO starts as you approach 750+. If you can't slow it down from there using air control then I'd consider that a problem. One basic rule is no glowing, not the top, not the collar.

That lines up with what I got this evening. Got up to low 600s then settled to 540. As the logs burned off and it went to more glowing than flames (hour after settled temp?) It was at high 200s on the collar.

About 3 hours after lighting this is where I was at. Fan still blowing some heat but expectedly dropped off from when it was cruising with flames. During cruising I had damper all the way down.

 

[jatoxico]

That lines up with what I got this evening. Got up to low 600s then settled to 540. As the logs burned off and it went to more glowing than flames (hour after settled temp?) It was at high 200s on the collar.

About 3 hours after lighting this is where I was at. Fan still blowing some heat but expectedly dropped off from when it was cruising with flames. During cruising I had damper all the way down.

If you feel like you have control add more fuel and see how it goes. Mostly reloads are different than cold starts in that the temp will want to climb much faster and can lead to a runaway if you don't pay attention.

The solution is to cut the air faster and more severely than you would on a cold start. Still have to keep the fire burning lively so you don't smolder but don't let your temps climb too high before cutting back and you will stay controlled and get longer burn.

 

[Woody Stover]

even with damper all the way down the fire keeps going though is showing some reaction to reduced air.

I think if you can cut the air enough to get a lazy fire coming off the wood, and from the secondary, the stove should burn longer and put out good heat while doing that.

 

[MAD MARK]

That lines up with what I got this evening. Got up to low 600s then settled to 540. As the logs burned off and it went to more glowing than flames (hour after settled temp?) It was at high 200s on the collar.

About 3 hours after lighting this is where I was at. Fan still blowing some heat but expectedly dropped off from when it was cruising with flames. During cruising I had damper all the way down.

Those pictures express just how disappointing the burn times are from 530pm to 814pm. So you really only had good heat for probably 1:45 to 2 hours.

I think you should be able to pack it a little tighter. And have you tried the top down approach?

 

[SculptureOfSound]

I find my initial load from a cold start burns quite a bit faster than a reload since you can't cut the air nearly as quickly. That being said, I've got more than that left at 3 hours and I'm burning super dry bug eaten (light, not many BTUs in it) pine, and moving the temp from 68 to 74 or 75 in that time. On reloads the temp will climb up to high 70s or even 80 in the room with the insert and that's at about 15 degrees outside.

How long from the cold start until you start cutting the air? You're either burning too much off at the start, not closing air soon enough, or else your draft is wicked strong and the burn rate is too high even with the air down.

 

[blacktail]

Once you're comfortable with the stove control, load that thing up. That picture is about a half load.

 

[Riverside_eng]

If you feel like you have control add more fuel and see how it goes. Mostly reloads are different than cold starts in that the temp will want to climb much faster and can lead to a runaway if you don't pay attention.

The solution is to cut the air faster and more severely than you would on a cold start. Still have to keep the fire burning lively so you don't smolder but don't let your temps climb too high before cutting back and you will stay controlled and get longer burn.

I have no doubt I could get hotter and longer on reload. For as unimpressive as it was at the end, I did not bother to reload because I would not be there to observe the performance.

Those pictures express just how disappointing the burn times are from 530pm to 814pm. So you really only had good heat for probably 1:45 to 2 hours.

I think you should be able to pack it a little tighter. And have you tried the top down approach?

Definitely could have packed tighter. I kept it fairly open so lighting was easy. I had a few instances where I didn't allow enough air or some other issues that lead to smoldering so I probably over biased to airflow to my detriment.

Once you're comfortable with the stove control, load that thing up. That picture is about a half load.

Good to know that is considered half full, probably means yesterday morning was less than a quarter full!

 

[Riverside_eng]

I find my initial load from a cold start burns quite a bit faster than a reload since you can't cut the air nearly as quickly. That being said, I've got more than that left at 3 hours and I'm burning super dry bug eaten (light, not many BTUs in it) pine, and moving the temp from 68 to 74 or 75 in that time. On reloads the temp will climb up to high 70s or even 80 in the room with the insert and that's at about 15 degrees outside.

How long from the cold start until you start cutting the air? You're either burning too much off at the start, not closing air soon enough, or else your draft is wicked strong and the burn rate is too high even with the air down.

I probably cut the air at about 10-15 minutes in. With how it caught I probably could have cut it at maybe 5 minutes.

Not sure the cause but I can never get the flames down to "lazy". Could that be a symptom of waiting too long to cut the air or just a very strong draft?

 

[jatoxico]

I probably cut the air at about 10-15 minutes in. With how it caught I probably could have cut it at maybe 5 minutes.

With experience you'll most likely settle into a most common routine but there is no one formula for when and how much to cut air since draft conditions and wood quality vary.

[/QUOTE]Not sure the cause but I can never get the flames down to "lazy". Could that be a symptom of waiting too long to cut the air or just a very strong draft?[/QUOTE]

Lazy is a bit relative but if you can keep stoves temps from running away from you then you should be OK. But you ought to be able to get good secondary burn activity. This should be evident in the early/mid-way through a burn cycle when the wood is outgassing. Secondary activity will slow and then mostly stop as you progress toward the coaling stage.

 

[Riverside_eng]

With experience you'll most likely settle into a most common routine but there is no one formula for when and how much to cut air since draft conditions and wood quality vary.

Lazy is a bit relative but if you can keep stoves temps from running away from you then you should be OK. But you ought to be able to get good secondary burn activity. This should be evident in the early/mid-way through a burn cycle when the wood is outgassing. Secondary activity will slow and then mostly stop as you progress toward the coaling stage.

Not sure if I am getting secondary burn. I can see the gas burning as it is exiting the log, shooting flame that is coming with some force out of the faces of the log, differing from the waving general flame of the surface wood burning. However it is at the surface of the log and not from the burn tubes. The only time I have gotten secondary burn flames from the tubes was when I walked off to do something up stairs and came down to it rolling away at fairly open damper a half hour later. This is part of the reason why I have tried to wait longer to close it down, though that may be eating into my burn times.

Is the flame at the log from off gassing similar heat results to it burning at the tubes or am I running something incorrectly or not hot enough?

 

[blacktail]

If you want more fire, you gotta give it more fuel.

 

[FPX Dude]

YEP, well put!

 

[Riverside_eng]

To give a little bit of an update. I have been loading a bit more in:

3 Bricks
1 large Split
2 Half's or Thirds of a large Split
3-4 peices split smaller than thumb size

I can regularly get up to a fair temp and decent heat output for 3.5 hrs on the first loading. Have been cutting the air back to short of full damper and the heat output seems to be better. So may have been choking it down too much which would drop overall temp and hinder heat output due to lower temperature of the stove surface.

Though it has been a bit warmer so further testing to come as winter goes on. With stove up to temp throwing one or two bricks in 2 hours in gives a healthy boost to temp output.