Charcoal can be made by burning wood in different ways - in a Firepit or in either a charcoal hearth or charcoal oven. This guide deals with the hearths, for firepits, see the firebuilding guide.
A brief comparison of advantages of the two methods:
Ovens and hearths operate in the same fashion. A charcoal oven has a higher starting wood cost, higher output capacity and no regulator setting.
Advantages of a charcoal hearth:
Advantages of Firepit:
In general, a well-run batch in a hearth can be finished in less than five teppyminutes. That means a hearth produces Charcoal at around 20 per minute
Note: in the reminder of this guide, "hearth" refers to any of the following: Charcoal hearth, charcoal oven or the charcoal brazier, unless otherwise noted.
When you select your charcoal hearth, you will see a menu showing the amount of Wood and water in your inventory. It will also tell you how much charcoal it will produce on success, and that you need (some amount) of Wood to start the process.
NOTE: You will need substantially more than the starting amount of wood to finish the process.
In practice, starting the hearth with 130 wood in inventory more than is required is comfortable. It will usually take somewhere between 70 and 100 wood (above the minimum) for the hearth to finish (assuming zero regulation, see below). It is also wise to have a few jugs of water (at least three, more is better) on hand. This means you will likely want 200 - 250 wood on hand before starting the charcoal hearth.
Anticipated: The other differences between the hearth and the oven are that the oven is slightly slower/more random and has no regulator (works as if it is on regulator setting 0 - see below).
The regulator appears to control the amount of random shift in the hearth's behavior; increasing the regulation reduces the randomness and increases the time between ticks (allowing you more time to respond). Try starting with the hearth set to no more than 2. If you have problems, increase the regulation a step or two, and try again. With some experience, you should be able to make the hearth work most of the time with no regulation. Regulation is excellent for controlling randomness when running multiple hearths (4+)and with patience you can succeed with efficiencies less than 2:1 without using any water (except to speed cooling to take your cc and start again faster).
You cannot change the regulation once the hearth is running, so make sure it's set where you want it before you start.
When you press the "Begin" button, the display immediately changes to six horizontal bar scales: Heat, Oxygen, Wood, Water, Danger, and Progress. Here's what they mean:
In addition, there are controls:
Heat is what makes Charcoal happen. The higher your heat level, the faster the progress bar moves, and the sooner your Charcoal is done. So the first goal is to keep that heat bar as high as possible. Anything less than halfway is going to bring your progress to a crawl, and at less than a third, you'll hardly see the progress bar move at all. Resist the temptation of watching this bar closely, the danger bar gives a much better view.
Oxygen is important for controlling heat. If you don't have enough oxygen, you can't burn wood, and the heat level will drop. It is a very important bar to keep an eye out. Don't let it get to 0 (the fire will snuff), and avoid it being excessively high (more than 2/3). Also, oxygen should be higher than the wood. (Note: I use the opposite rule -- O2 should usually be lower than wood; when it goes higher I start doing things to make it lower. ---Ouijdani)
Wood is your heat source. Adding wood will increase the heat level of the hearth, provided there's enough oxygen. Adding wood also appears to make the oxygen level drop slightly. As the hearth runs out of wood, you'll see the heat level drop, and the oxygen level will shoot up, even with the vent closed.
Adding Water will reduce heat levels, which is normally a bad thing. However, it also tends to dramatically reduce danger level (see below), which is definitely a good thing. Adding water is normally not neccessary, but it sure is a nice thing in case of an emergency.
Danger level is the bar to keep a close eye on. It appears to relate primarily to heat, oxygen, and water. As your heat and oxygen levels rise, the danger bar also rises. If you add water, the danger bar tends to drop. The danger bar must not be allowed to reach 100%, or the wood combusts, ruining the entire batch. If the danger bar gets too low (about 1/2), the progress will quickly come to grinding halt. Thus, the best way to run a hearth is to keep this bar high (at least 2/3) but not too high (not above 5/6).
The vent controls are the final piece of the puzzle. Closing the vent (left button) reduces the amount of oxygen in the hearth, and tends to cause a small increase in heat and reduces the danger level, especially in the long run. Opening the vent (right button) increases the amount of oxygen in the hearth, and tends to cause heat to drop and the danger to increase, provided there is enough wood to burn.
Okay, so you've got the theory, now how about the practice?
First off, get your 250 wood, several jugs of water, and hearth/oven together. Pin the hearth, check the regulation level and set as necessary, and then click Begin.
Every tick (once every few seconds), you'll see the bars move around a little. Here's what to focus on:
Start with the vent halfway open, and work on getting the danger bar to about 2/3rds. Try to control danger and oxygen levels by adding wood or by waiting, rather than resorting to the vent controls. If the danger bar starts getting too high, close the vent, and wait. If it gets extremely high, hit the water. The key to the process is to act cautiously, and use some forethought ("I just added some wood, that'll make the danger go up, so I'll wait a couple of ticks before adding any more"). Above all, practice!
Kraus has written a nice charcoal guide which explains that the temperature cycle is sinusoidal. His page explains why you need adjust your levels while the temperature is in mid-range, and then let the hearth coast through the peaks and valleys.
The second fastest way to lose control of the hearth is to not anticipate the water in the hearth going away. For any given amount of wood, the hearth will generate much more heat if there is NO water in it, than if there is ANY water in it. Once the last of the water goes away, the heat will start to rise much more rapidly. (If the heat was going down by a lot, it will go down by much less, and will likely start going up instead.) If you shaved your safety margins while you had water in the oven, you may be forced to add more water to avoid catastrophe. When water starts getting low, let the heat start to drop to where you can more easily maintain it.
This is why you can prevent the danger level from getting out of control by closing the vent; and conversely get out of a low-energy mode by opening it. This is counter-intuitive, but true nontheless.
It was initially posted by Amanesus in Tale2, with additional comments by Shadus, and various others. Details have been changed for changes in our "generation".
In the days of our grandfathers, bonfires were built by pretty much everyone. Fire safety issues aside, they performed most of the same tasks we use firepits for today.
In comparison to charcoal hearths, bonfires were...
Our grandfathers also built Charcoal Ovens, and Braziers . Their Hearths only generated 50 Charcoal at a time, but cost much less in the way of materials to create. Their ovens generated 100 charcoal, and their braziers 300. (The Braziers required special knowledge, and a Focus of 7 to use.)