Why Heating Matters
Heat keeps production devices running, but a poor fuel setup can create unnecessary belt traffic, machine use, and refueling work. The useful question is not simply which fuel has the largest heat value; it is whether your fuel supply can cover every heat consumer attached to a heating device.
In Alchemy Factory, heating devices burn fuel while connected devices consume heat at their listed speed. Fuel affects how long the heating device can operate before it needs another item. It does not make a heat consumer process faster.
Start by identifying the heat consumers on each heating setup, add their heat speeds together, then choose a fuel pipeline that can reliably keep up. The Codex Heating Calculator is useful for comparing the number of furnaces, consumers, fuel types, and upgrades in one place.
Heat Consumers and Their Demand
Each listed heat consumer has a fixed heat speed. If several devices share a heating system, their combined heat draw determines the heat requirement you need to support.
| Heat consumer | Heat speed |
|---|---|
| Iron Smelter | 9 |
| Crucible | 4 |
| Stackable Crucible | 6 |
| Thermal Extractor | 80 |
| Paradox Crucible | 1200 |
| Kiln | 15 |
| Alembic | 108 |
| Athanor | 32 |
| Advanced Alembic | 270 |
| Advanced Athanor | 360 |
A Crucible uses 4 P/s regardless of what it is processing. That makes planning straightforward: three Crucibles require 12 P/s from their consumer demand alone.
The heating setup should be planned around the devices actually connected to it. For example:
- Two Crucibles need 8 P/s.
- One Kiln and one Iron Smelter need 24 P/s.
- An Alembic and an Athanor need 140 P/s.
- A Thermal Extractor needs 80 P/s by itself.
The source material distinguishes between fixed consumer demand and Cauldron demand, which can vary by recipe. When working with a Cauldron, check its recipe tooltip instead of assuming a single universal heat value.
In Early Access, heating devices themselves had a base heat draw: 1 P/s for a Stone Furnace and 4 P/s for a Blast Furnace. Source material states that version 1.0 removed the base heat cost of heating devices. If you are using an Early Access version, account for that difference when checking old examples or guides.
Fuel Heat Values
Fuel heat value determines how much total heat one item provides before another item must be supplied. The Codex lists the following fuel values.
| Fuel | Heat value |
|---|---|
| Logs | 2000 |
| Coal Ore | 30000 |
| Plank | 20 |
| Charcoal | 40 |
| Charcoal Powder | 48 |
| Coke | 600 |
| Coke Powder | 660 |
| Coal | 540 |
| Black Powder | 6000 |
| Blast Potion | 24000 |
| Panacea Potion | 320000 |
Raw logs can be burned directly, but processing them increases the total heat from the original log. One log provides 2000 heat when burned directly. The same log can become 200 planks, and each plank provides 20 heat, for 4000 total heat.
Further processing continues that pattern in the cited examples.
| Starting material path | Total heat from one original log |
|---|---|
| Burn the log directly | 2000 |
| Convert to 200 planks | 4000 |
| Convert to charcoal | 8000 |
| Convert charcoal to charcoal powder | 9600 |
These figures show why direct burning is usually the simplest option, not the most heat-efficient one. Refining fuel asks for extra processing space and machines, but it stretches the energy available from the same starting material.
Fuel Efficiency upgrades affect fuel heat value, so calculator results should match the upgrade level you actually use. Do not compare a setup using upgraded fuel efficiency with an unupgraded baseline and assume the difference comes from the fuel chain alone.
Choosing a Fuel Path
There is no single best fuel path for every factory. The practical choice depends on whether you are constrained by money, floor space, belt capacity, available processing, or future recipe needs.
Logs and planks
Logs are an immediate fuel option with a heat value of 2000. Planks have only 20 heat each, but a log produces 200 planks, so processing one log into planks doubles the total heat to 4000.
Use logs when you need the shortest path from supply to heating. Use planks when you can support the added item volume and want more heat from the same wood input.
Charcoal and charcoal powder
Charcoal raises the cited total heat from one original log to 8000. Charcoal powder provides 48 heat per item, reaching 9600 total heat in the log-processing example.
Player discussion and guide material describe charcoal powder as a strong choice when gold efficiency matters more than space. Its drawback is operational: it requires charcoal production and grinding, which adds machines and handling.
Coal, coke, and coke powder
Coal Ore has a heat value of 30000 when burned directly. Coal has a heat value of 540, Coke has 600, and Coke Powder has 660. Coal-based fuel is presented as easier to manage because higher heat per item reduces belt pressure and can simplify compact builds.
Source material also notes that once coal is unlocked, it can be heated into Coke without the failure rate associated with Charcoal. Coke is needed for later recipes, so a coal pipeline can serve both production and heating rather than duplicating systems.
Powders and potions
Powders and potions provide high heat values per item. Black Powder provides 6000 heat, Blast Potion provides 24000, and Panacea Potion provides 320000.
Panacea Potion also functions as fertilizer according to the source material. That can make it useful for a factory layout where one fuel belt also supports nurseries, though it remains a late-stage option compared with basic wood and coal processing.
Planning a Reliable Heating Setup
A reliable heating line begins with demand, then moves backward through fuel delivery and production. Avoid selecting fuel only because it has a high number in a list. A fuel source is useful only if the rest of the factory can produce and deliver it consistently.
Use this planning order:
- List every heat consumer connected to the heating device.
- Add their heat speeds.
- Check the current game version if you are relying on an older furnace base-draw example.
- Choose a fuel path based on your limits: cost, layout space, belt congestion, or recipe overlap.
- Verify the arrangement with the Heating Calculator.
- Leave enough fuel production and delivery capacity to avoid interruptions.
The available heating devices in the Codex calculator are Stone Furnaces and Blast Furnaces. The source material describes the Blast Furnace as having the same consumer speed as a Stone Furnace, while offering more heat capacity and more slots. That means moving to a Blast Furnace is not a way to speed up the attached consumer; it is a capacity and layout decision.
A compact fuel may reduce the number of items moving along belts, while a more processed fuel may improve the total heat gained from raw material. Those benefits are different. Coal is described as convenient for compact setups, while charcoal powder is described as efficient when spending is the primary concern.
| Factory priority | Suitable direction from the sources |
|---|---|
| Fewest processing steps | Burn logs directly |
| More heat from wood | Process logs into planks or charcoal |
| Better gold efficiency | Use charcoal powder |
| Lower belt congestion | Use coal-based fuel |
| Long-term shared production | Build around coal and coke |
| Extremely high heat per item | Use potions when available |
For a small line, simple fuel may be easier to operate than an elaborate refining chain. For a large floor with many consumers, belt traffic and repeated refueling become more important, making compact high-value fuels more attractive.
FAQ
What is the best early fuel?
This alchemy factory heating guide recommends considering charcoal or charcoal powder when gold is tight, based on the source material’s efficiency discussion. Logs are simpler, while planks provide more total heat from the same log.
Do planks provide more heat than logs?
Yes. One log provides 2000 heat directly. If it becomes 200 planks worth 20 heat each, the total becomes 4000 heat.
Does fuel make machines run faster?
No. Fuel changes how long the heating device runs before it needs another item. It does not change the processing speed of heat consumers.
Is coal better than charcoal powder?
They serve different goals. Charcoal powder is described as stronger for pure cost efficiency, while coal-based fuel is easier to manage and reduces belt congestion.
How do I calculate required heat?
Add the heat speed of every connected consumer. For example, three Crucibles need 12 P/s because each Crucible uses 4 P/s.