# Hot air - Stage 3 (technology)

internal name `hot-air-mk03` · tier 5 (Chemical science pack, [tier 5](https://factorio.kalzumeus.com/tier/5.md))
HTML page: https://factorio.kalzumeus.com/tech/hot-air-mk03/

## Cost

900 units of (1 × [Chemical science pack](https://factorio.kalzumeus.com/item/chemical-science-pack.md), 2 × [pY science pack 2](https://factorio.kalzumeus.com/item/py-science-pack-2.md), 3 × [Logistic science pack](https://factorio.kalzumeus.com/item/logistic-science-pack.md), 6 × [pY science pack 1](https://factorio.kalzumeus.com/item/py-science-pack-1.md), 10 × [Automation science pack](https://factorio.kalzumeus.com/item/automation-science-pack.md)), 120 s each.

## Requires (3)

- [Coal Power - Stage 2](https://factorio.kalzumeus.com/tech/coalplant-mk02.md)
- [Coke processing - Stage 3](https://factorio.kalzumeus.com/tech/coke-mk03.md)
- [Hot air - Stage 2](https://factorio.kalzumeus.com/tech/hot-air-mk02.md)

## Leads to (0)

- none

## Unlocks (5 recipes)

### Hot air (`hot-air-3`)

- 2 s · tier 5
- Ingredients: 20 × [Hot stone brick](https://factorio.kalzumeus.com/item/hot-stone-brick.md), 150 × [Pressurized air](https://factorio.kalzumeus.com/fluid/pressured-air.md)
- Results: 500 × [Hot air](https://factorio.kalzumeus.com/fluid/hot-air.md), 20 × [Stone brick](https://factorio.kalzumeus.com/item/stone-brick.md)
- Made in: Regenerative heat exchanger
- Unlocked by: [Hot air - Stage 3](https://factorio.kalzumeus.com/tech/hot-air-mk03.md)

### Hot stone brick (`hot-stone-brick`)

- 3 s · tier 5
- Ingredients: 20 × [Warmer stone brick](https://factorio.kalzumeus.com/item/warmer-stone-brick.md), 100 × [Outlet gas (stage 4)](https://factorio.kalzumeus.com/fluid/outlet-gas-04.md) (≥1000°C)
- Results: 20 × [Hot stone brick](https://factorio.kalzumeus.com/item/hot-stone-brick.md), 100 × [Outlet gas (stage 4)](https://factorio.kalzumeus.com/fluid/outlet-gas-04.md) (750°C)
- Made in: Regenerative heat exchanger
- Unlocked by: [Hot air - Stage 3](https://factorio.kalzumeus.com/tech/hot-air-mk03.md)

### Outlet gas (stage 4) (`reheat-outlet-gas-2`)

- 4 s · tier 5
- Ingredients: 100 × [Outlet gas (stage 4)](https://factorio.kalzumeus.com/fluid/outlet-gas-04.md) (≤500°C), 50 × [Hot Molten Salt](https://factorio.kalzumeus.com/fluid/hot-molten-salt.md) (≥1950°C)
- Results: 95 × [Outlet gas (stage 4)](https://factorio.kalzumeus.com/fluid/outlet-gas-04.md) (1000°C), 50 × [Molten Salt](https://factorio.kalzumeus.com/fluid/molten-salt.md)
- Made in: Heat exchanger MK01, Heat exchanger MK02, Heat exchanger MK03, Heat exchanger MK04
- Unlocked by: [Hot air - Stage 3](https://factorio.kalzumeus.com/tech/hot-air-mk03.md)

### Warm stone brick (`warm-stone-brick-2`)

- 3 s · tier 5
- Ingredients: 20 × [Stone brick](https://factorio.kalzumeus.com/item/stone-brick.md), 100 × [Outlet gas (stage 4)](https://factorio.kalzumeus.com/fluid/outlet-gas-04.md) (≥500°C)
- Results: 20 × [Warm stone brick](https://factorio.kalzumeus.com/item/warm-stone-brick.md), 100 × [Outlet gas (stage 4)](https://factorio.kalzumeus.com/fluid/outlet-gas-04.md) (250°C)
- Made in: Regenerative heat exchanger
- Unlocked by: [Hot air - Stage 3](https://factorio.kalzumeus.com/tech/hot-air-mk03.md)

### Warmer stone brick (`warmer-stone-brick-2`)

- 3 s · tier 5
- Ingredients: 20 × [Warm stone brick](https://factorio.kalzumeus.com/item/warm-stone-brick.md), 100 × [Outlet gas (stage 4)](https://factorio.kalzumeus.com/fluid/outlet-gas-04.md) (≥750°C)
- Results: 20 × [Warmer stone brick](https://factorio.kalzumeus.com/item/warmer-stone-brick.md), 100 × [Outlet gas (stage 4)](https://factorio.kalzumeus.com/fluid/outlet-gas-04.md) (500°C)
- Made in: Regenerative heat exchanger
- Unlocked by: [Hot air - Stage 3](https://factorio.kalzumeus.com/tech/hot-air-mk03.md)