1.20 charcoal burning using kiln door and iron trapdoor punishes you by cutting out several stacks of firewood worth of charcoal.

[tonechild]

As the handbook states, you can now create a permanent charcoal kiln by using the kiln door and iron trap door. This is awesome, but it leaves big holes in the charcoal kiln that just using dirt doesnt.  There's always a hole of missing charcoal beneath the iron door (an entire stack), and around 8 half-stacks gone all around it.  In addition there's usually a missing stack in front of the kiln door.  SO you end up losing around 6 stacks worth of charcoal by using this "upgrade"

Is this a bug or a thing?  The handbook makes no mention of it, other than stating you can use the kiln door and the iron trap door.  It's quite expensive to make the iron trap door and kiln door, so it seems odd to be punished for investing in those when dirt is just free and everywhere.

I also tried several different layouts in creative mode.  It seems the most upgraded kiln door prevents you from losing a stack, but the iron trap door will cause you to lose 6 stacks worth of charcoal (1 whole stack and 8 half stacks all around it)  directly below it.  Even if you cover the iron trap door in dirt as well.  The iron trap door costs 2 iron nails and strips + 2 iron plates.  Hoping this is a bug? because it doesn't seem worth losing that much charcoal in exchange for 5 iron ingots vs using dirt which is everywhere.

 

Edited January 31, 2025 by tonechild

[Maelstrom]

Seems like a bug.  To mitigate the trap door, place it in the corner of your kiln, so you reduce the loss of the surrounding blocks down to 3 instead of 8.  Even with losing charcoal, I'm pleased to see this implemented.  I've wanted this ever since joining the game on 1.14.10.

[StCatharines]

We lose charcoal with the doors? I haven't experienced that at all, but I honestly might have just missed it. I've been using the iron trap door in a brick block charcoal kiln. It's nice to see such a QoL feature added, I hated having steel tools and still making charcoal pits out of dirt or whatever block I had handy.

[tonechild]

Yeah I love the new charcoal kiln update, just wish I wasn't losing additional charcoal because I'm using it.  It's not just me is it?  I wonder if I'm doing something wrong now.  I mean I've also tried it in creative mode as well and it loses charcoal for me every time.

[Thorfinn]

"Kids and their newfangled ways! Dirt was good enough for my grandpappy, it was good enough for my dad, and by, gum, it's good enough for me!"

[tonechild]

So this is what it looks like when I open the fire kiln door after making charcoal, note the first image showing how much charcoal was lost!  The second image shows the top configuration and then the last is another image of the front but a few steps back.
 

It's not always the same every run, sometimes I lose or save more than others.  It seems like some random amount is just removed each time. Though mostly under the iron trap door and behind the kiln door.  In this image, two stacks were missing from under the iron door  

Edited January 31, 2025 by tonechild

[Maelstrom]

The charcoal generation in the 8 blocks around the iron trap door is normal.  The column directly below it looks a wrong, there should be at least 8 layers of charcoal there.  I suspect the trap door should be located in the block below were you have it.

The charcoal behind the door looks right as well.  Remember that a block of firewood produces up to 8 layers of charcoal.  Sometimes 2 blocks of firewood generates exactly 8 layers of charcoal.

[tonechild]

17 minutes ago, Maelstrom said:

The charcoal generation in the 8 blocks around the iron trap door is normal.  The column directly below it looks a wrong, there should be at least 8 layers of charcoal there.  I suspect the trap door should be located in the block below were you have it.

The charcoal behind the door looks right as well.  Remember that a block of firewood produces up to 8 layers of charcoal.  Sometimes 2 blocks of firewood generates exactly 8 layers of charcoal.

I thought that too at one point, but that gap is where you put the fire pit part of the charcoal kiln.  in my tests, if you do have any gaps at all the charcoal kiln will just fail and burn everything up. Unless the fire pit should be adjacent to the other piles maybe? But that isnt the case for the dirt variant.

Edited January 31, 2025 by tonechild