"Shrinking" an oversized stove by adding firebricks?

[TradEddie]

Has anyone ever tried adding extra firebricks to an oversized stove or insert to get better performance from smaller loads?

My Lopi Freedom is a great performer, unfortunately too good on most days, especially since it's in a room with limited doorways to move air into other areas of the house. I have to really pay attention to keep that stovetop hot enough to burn cleanly, but not bake us out of the room. I now wish I'd bought the smaller model, but that's water under the bridge. My problem is not helped by only having well seasoned oak available right now...

Recently, I bought a box of firebricks with the intent of "shrinking" the firebox. My hope was that if I could concentrate the fire and airflow to the middle of the unit, maybe I could get less overall heat reaching the convection jacket, while maintaining stovetop temperature. Perhaps some additional thermal mass would help too. That box of six bricks is barely 0.2cuft, but my initial efforts do seem to have made an improvement.

Before I go out and buy some more firebricks, I hope I can learn from the advice and experience of folks here. Any thoughts? Anybody have success or failure with this approach? I tried to place them where they weren't obstructing heating of the secondary or airwash air channels, but am not sure what the pros and cons might be.

TE

 

[begreen]

Should work, the main problem is securing the bricks in some fashion so that they don't collapse and fall into the fire or ashes.

 

[Dmitry]

I wish i had this problem. Too powerful of a stove and oak that too dry. Damn.

I woud think of adding some kind of a duct with inline fan to suck all the extra hot air out of the room, prolly.

 

[brenndatomu]

I used bricks to "shrink" a wood furnace firebox...it worked well...was happy with the results, had no problems with it.

 

[begreen]

I wish i had this problem. Too powerful of a stove and oak that too dry. Damn.

I woud think of adding some kind of a duct with inline fan to suck all the extra hot air out of the room, prolly.

Not a bad alternative. TradEddie, would this option be worth exploring? If yes, can you post a sketch of the floorplan showing the insert location?

 

[TradEddie]

I've certainly thought about a duct like that, I even bought a fan and non-insulated duct at a store closeout sale, but there isn't an obvious or easy place to run it to. I can run my central air to try even out room temperatures, (I've even tried blocking return ducts in other rooms) but it does very little, and any duct fan would be much lower cfm.

TE

 

[begreen]

Some places are easier than others. Some areas work well with just a fan on the floor in an adjacent room. It's hard to comment without more info.

 

[EatenByLimestone]

I've let ash build up to shrink a stove.

I've thought of laying the bricks along the bottom to shrink a stove and move a small fire up to the top near the burn tubes so it'll burn more efficiently. Haven't gotten around to it yet.

If you build up the base, the walls aren't any different than they are now. They aren't any more likely to fall in than they were before.

 

[bcrtops]

Yes, I have done this a couple of times. Used full sized firebricks, so they sat well on the bottom of the stove. Primarily for summer &/or shoulder season -- keeps the fire central & secondaries work fine in our stove. Not this year -- when we get a cold snap, those hot bricks are a pain to remove, when you want to go back to a full sized fire. We just build a smaller fire, keeping it centered, or (wife), does it to one side (which doesn't keep the secondaries going nearly as well.) Worked well in our T5, extra bricks on the sides, keep fire central N/S load.

Edit: lay bricks on side, they don't need to go to top -- just keeping fire/coals constricted to center, & they won't fall over if full-sized.

 

[dafattkidd]

I have an oversized insert and I don’t have this issue. One strategy that I use when there is a low heat demand is building small fires that are stacked tall and narrow in the center of the fire box. Also leaving a thick bed of ashes tends to help hold coals a little longer. Another trick-depending on your tolerance and comfort level- is allowing the house temps to drop a bit lower than you would on a colder day. Then the extra BTUs are welcomed. Not sure if this helps. Of course everyone’s set up and preferences are different. This is what works for us. Cheers,

 

[TradEddie]

Just a quick update on this, one year on. I experimented with the firebricks on the bottom, which was convenient, but I wasn't able to use all the bricks or it would limit the doghouse air. I then placed the bricks upright on the side walls, and "secured" them with a twisted coat hanger. This appears to work, they stay in place perfectly, it's quicker to heat up with a small fire, but on a couple of occasions, inexplicably, I've had the stovetop temperature shoot too close to overfire range for my liking, even with air fully closed. The first time may be been a little alcohol-related bad judgement on reload, but it's happened a few times. I can't really understand how the extra bricks could do this, but I'd never experienced it before adding the bricks.

Any thoughts on how adding bricks to the sides could do this? Is it two sides of the same coin, I want it to heat faster, but now complain when it heats too fast?

TE

 

[Hogwildz]

The bricks are insulting the firebox, letting less heat out through the steel, containing more heat in the box.
Why not just load smaller loads of fuel?