Why Stoves Lose Power In Cold And Wind

A stove that boils water in three minutes in a garden can take twenty on a winter mountainside, or fail to light at all. Two separate effects cause it.

Canisters run on vapour pressure

A gas canister holds liquefied fuel. What feeds the burner is the vapour above that liquid, and vapour is produced only because the fuel is above its boiling point.

As temperature falls, less fuel evaporates and the pressure inside the canister drops. Below a certain point the flow becomes too weak to sustain a useful flame.

Running the stove makes this worse. Evaporation itself removes heat, so the canister cools during use and the flame weakens as the meal cooks.

Fuel mixes differ

Canister fuel is usually a blend. Propane vaporises at much lower temperatures than butane, which is why winter blends contain a greater proportion of it.

The blend separates in use. Propane leaves the liquid first, so a partly used canister is progressively more butane and performs worse in cold than a full one.

This is why a canister that worked yesterday can fail today at the same temperature, and why people carrying canisters in winter tend to carry them nearly full.

Liquid fuel avoids the problem

Liquid fuel stoves pressurise the bottle with a pump rather than relying on the fuel's own vapour pressure, so ambient temperature does not govern flow.

They require priming, which means burning a small amount of fuel to heat a vaporising tube before the stove runs properly. This takes practice and produces flames.

They are also heavier, need maintenance, and demand ventilation and care with spilled fuel. The tradeoff is reliability in conditions where canisters simply stop working.

Wind removes the heat you made

Even with full fuel flow, moving air strips heat from the flame and the pot before it reaches the water. A modest breeze can multiply the fuel needed.

Windshields address this, but a shield wrapped fully around an upright canister stove traps heat against the canister, which is a hazard rather than an efficiency gain.

Integrated systems tackle it differently, with a heat exchanger on the pot base and a shroud that encloses the flame as part of the design.

Why melting snow changes the maths

Where snow is the water source, fuel consumption rises steeply. Melting requires a large amount of energy before any temperature rise begins.

Parties planning winter trips therefore calculate fuel by the number of melts rather than by days, and carry a margin, because running out means no water rather than cold food.

Cooking inside a tent or snow shelter introduces carbon monoxide risk that has killed people. Anyone considering it needs proper instruction on ventilation before relying on it.