Alchemy Factory Fuel & Heat: P Values, Tiers and Coke Powder

Heat in Alchemy Factory is measured in P, shown as P per second in every tooltip. Heating devices burn fuel to make heat; heat consumers sit on top of them and each draws a fixed amount. Fuel type never changes how fast a consumer works, only how long the heating device runs before it needs the next item. Version 1.0 removed the base heat cost that heating devices used to draw on their own.

Heating devices

DeviceFootprintOwn heat drawNotes
Stone Furnace3 x 3 tiles1 P/s in Early Access; base cost removed in 1.0The first heating device; a Stone Furnace placement is the 75.8% 'Fire It Up!' achievement.
Blast Furnace6 x 7 tiles4 P/s in Early Access; base cost removed in 1.0Same consumer speed as a Stone Furnace, just more heat capacity and more slots to gridlock.
Steam Boiler + Steam Heating PadTwo-partNot measured in the sourcesAdded in v0.4.4.4298 as 'a brand-new heating mechanic'; the boiler makes steam that heating pads deliver to consumers.

The base draw column is the one number on this page that changed at 1.0. Through Early Access a Stone Furnace used 1 P/s just to exist and a Blast Furnace 4 P/s, so an idle furnace with fuel in it slowly ate the stack. The 1.0 patch notes list "Removed the base heat cost of all heating devices," which means the worked example below (13 P/s for a furnace plus three crucibles) is now 12 P/s.

Heat consumers

DeviceHeat drawNotes
Crucible4 P/s eachFixed regardless of what it processes: planks, stone or sage all cost 4 P/s. Three crucibles on a furnace needed 13 P/s total in EA (12 + the furnace's own 1).
CauldronVaries by productThe only consumer whose draw depends on the recipe: the clay recipe ran at 4.6 P/s for 16.7 clay per minute at base speed, 6.9 P/s at +50% factory efficiency.
Kiln, Smelter, Alembic, Athanor, Thermal ExtractorFixed per device typeExact values were not listed in the transcript sources; read the tooltip P value and add them up per furnace.

To size a furnace, add up the consumers on it. The March 2026 guide's example: three crucibles making plant ash from sage need 3 x 4 = 12 P/s, plus the furnace's own 1 P/s in that version. Whether the crucibles hold planks, stone or sage makes no difference. Heating devices also do not speed anything up; two crucibles run at the same rate on a Stone Furnace and a Blast Furnace.

The three fuel tiers

TierExamplesNotes
RawLogs, planks, coal oreCan be burned directly but meant for refining. A player's own numbers on the Steam board: a 200-copper log gives 22 heat per plank, a 4,800-copper coal ore gives 594 heat per coal.
RefinedCharcoal, coal, cokeProcessing a raw fuel roughly multiplies its heat; guides say refining is always worth it.
Powders and potionsCharcoal Powder, Coke Powder, Black Powder, Blast Potion, Panacea PotionHighest heat per item. Black Powder's heat value was doubled in v0.5.4467. Panacea Potion doubles as fertiliser, so a single belt can feed both furnaces and nurseries on a floor.

The practical ladder most players climb: planks in the tutorial, charcoal at tier 5, coal and coke powder at tier 6 when coal ore unlocks, black powder from a cauldron in the mid-game, then blast potions and finally panacea potions, which are fuel and fertiliser at once. Late-game factories run one belt of high-grade fuel down an aisle or across a whole floor rather than a dedicated fuel line per machine group.

Coke powder: Athanor or coal ore?

MethodRecipeFor one 60/min beltVerdict
Athanor route12 Charcoal Powder to 1 Coke Powder6 Athanors, 40 crucibles, 60 grinders; the setup itself burns about 34 coke powder per minuteAbout half the material cost, orders of magnitude more space
Coal ore routeCoal ore through a stone crusher gives 120 coal; 1 coal to 1 Coke PowderThree stone crushers; the setup burns about 3 coke powder per minute, net 57Recommended: a fraction of the footprint, no fertiliser, self-fuelling loop

New players see the 4,800-copper price of coal ore and reach for the Athanor route because it costs about half as much per powder. The April 2026 comparison argues the other way: whatever you burn or build with coke powder sells for far more than the ore cost (two coke powder go into a transformation potion that sold for 620 copper in that version), money is a function of in-game days, and the Athanor route needs roughly ten times the machines and fuels itself. Its closing advice is to feed leftover planks from advanced fertiliser into Jupiter relics or the trash, not into coke powder, so that fertiliser production never depends on fuel production.

Catalysts (Advanced Athanor)

CatalystEffect
Unstable CatalystAlters product generation probabilities in an Advanced Athanor
Fertile CatalystDoubles product output
Resonant CatalystGenerates all outputs simultaneously
Eternal CatalystRecipe consumes no materials

All four were introduced with the June 2026 recipe rebalance, which rebuilt every Advanced Athanor recipe around them. The same patch doubled Black Powder's sell price and heat value, so any fuel comparison you find dated before June 2026 undervalues black powder.

Sources checked:

Mechanics and P values: 'Heat and Fuel Guide', Uglarvisk, 24 March 2026 (v0.4.4), transcript. Coke powder comparison: 'The BEST Coke Powder Recipe', Uglarvisk, 8 April 2026. Base heat removal, Black Powder doubling and catalyst list: official patch notes 8 September 2026 and 2 June 2026. Player cost figures: Steam Discussions, 13 July 2026.