A recipe says to reduce the heat by half. You have been cooking on the Hillrein Zhengtu near 80% fan, so 40% looks like the obvious next setting. This is where fan speed wood stove cooking needs a little interpretation: halving the fan setting does not establish that you have halved the heat reaching the food.
The percentages in Zhengtu cooking guidance describe approximate fan settings. They are useful operating references, not measurements of burner output, pan temperature, or cooking speed. You can use them to get into the right range, then finish the adjustment by watching the dish.
Fan speed wood stove cooking: three numbers to keep separate
- Fan setting: how you are controlling the air supplied to the fire.
- Useful cooking heat: the heat actually reaching the cookware from the current burn.
- Food temperature: the result of that heat acting on a particular quantity of food over time.
There is no supplied calibration curve that converts a Zhengtu fan percentage into a fixed heat output. Nor should you assume that half the dial travel delivers exactly half the airflow. Even if airflow were measured, a live wood load and a warming chamber would still prevent a simple percentage-to-temperature conversion.
Why the same setting can give a different result
Think about the same pot at two moments. During startup, the chamber is still warming and the first pieces are catching. Later, the chamber is hot and an established load is releasing combustible wood gas. The same fan position is acting on two different fires.
Zhengtu uses annular oxygen intake to distribute air around the burn zone. Once temperature and airflow are suitable, gasification combustion helps burn much of the wood gas that would otherwise escape as smoke. Higher fan can make the visible flame lower while heat beneath the pot becomes stronger. Neither dial position nor flame height alone tells you the temperature of dinner.
Translate a recipe's medium heat into a cooking result
First identify what the instruction is trying to achieve. For a pot of soup, medium heat might mean maintaining a gentle simmer. For a pan of vegetables, it might mean a steady sizzle without rapid browning. Those are different demands; they do not share one universal Zhengtu percentage.
- Observe the food before adjusting. Is the liquid boiling hard, simmering gently, or barely moving?
- Make a modest fan change and watch the response. Avoid adding fuel at the same moment unless the fire is clearly running short.
- Account for the existing load. Turning down the fan does not instantly remove the heat of a full burning chamber and hot cookware.
- Adjust again only as the cooking result requires. Keep the pot attended throughout.
For established soup, porridge, or slower cooking, around 20% fan with one to two short dry pieces is a useful starting combination. For wok cooking, a fuller working load and about 80% fan usually provide the practical high-heat sweet spot. Leave room for airflow in either case. These are two cooking modes, not points on a guaranteed straight-line heat scale.
Do not calculate meal time from the dial
Moving from 80% to 40% does not mean the meal will take twice as long. Likewise, increasing from 80% to 100% does not promise a proportional reduction in cooking time. Maximum fan is possible, but it consumes wood faster. If a pot is already boiling as vigorously as the recipe needs, an extra push may spend fuel without improving the meal.
Start this fan-assisted wood stove with dry kindling and short wood around 10 cm long. Keep the first load loose, let the chamber warm, and increase the fan gradually after the fire establishes. Startup and refueling can still create visible smoke, even though visible smoke is low once the burn stabilizes under suitable conditions.
The Hillrein Zhengtu stove gives a cook useful airflow control for real outdoor meals. Follow the operating instructions in a suitable outdoor location. Treat the fan setting as your starting adjustment and the food as your feedback: that is more useful wood stove fire control than dividing one percentage by another.