Weber and AmazingRibs.com both teach that airflow sets the temperature of a charcoal fire, but they give different instructions for which vent to move. This guide compares Weber’s damper guide, its UK equivalent, Weber’s charcoal grill owner’s guide and AmazingRibs.com founder Meathead’s articles on using vents and setting up a charcoal grill. Celsius figures in parentheses are our own conversions.
Intake and Exhaust: The Basic Picture
AmazingRibs describes two oxygen controls. The intake damper sits near the charcoal and feeds it air. The exhaust damper (also called the flue, vent or chimney) lets combustion gases, heat and smoke out and, through the draft that creates, pulls air in through the intake. Close the intake and the fire starves even if the exhaust is wide open. The exhaust needs to stay at least partly open so that combustion gases do not smother the fire.
Weber describes the same hardware for a kettle: dampers in the bowl at the bottom and a damper in the lid. Its owner’s guide says more air means a hotter fire (up to a point) and more frequent refuelling, and that ash should be cleared regularly so it does not block the bottom vents.
Where Weber and AmazingRibs Disagree
Weber’s US guide suggests leaving the bottom dampers fully open and using the top lid damper to control temperature. Weber’s UK page says beginners should leave both open, then graduate to keeping the bottom vent fully open and steering with the lid vent.
AmazingRibs says the opposite for most cookers: the intake is “the engine”, so on most grills you control temperature mainly with the intake, keeping the exhaust fully open while you learn the cooker. It compares adjusting both at once to pressing the gas pedal and brake together. Its charcoal grill setup guide gives the same direction: control temperature with the bottom vents, not the top, and keep the top vents open at least halfway to avoid sooty buildup or bitter creosote on the food.
The sources do not reconcile these. AmazingRibs allows one exception: on leaky, poorly sealed cookers, if you cannot hit your target after fixing the leaks, try throttling the exhaust instead. Weber’s own pages are also not identical to each other. Its owner’s guide says closing the lid damper halfway is how to slow the fire, while the damper table below goes down to one-eighth open for low and slow.
Weber’s Damper Settings
Weber’s US page lists lid damper positions for each heat level, with the bottom dampers fully open:
- High, 450 to 550°F (232 to 288°C): fully open.
- Medium, 350 to 450°F (177 to 232°C): half open.
- Low, 250 to 350°F (121 to 177°C): a quarter open.
- Low and slow, 225 to 275°F (107 to 135°C): one-quarter to one-eighth open.
- Off: fully closed.
Weber warns that outside temperature, wind, how clean the grill is and even the food can shift these results. The UK page lists these in Celsius, but its low-and-slow range is 95 to 150°C, wider than the 107 to 135°C that the US range converts to.
How Much Charcoal for Which Heat
Weber’s UK page uses the chimney as a measuring cup: about a third of a chimney for low and slow, half for longer indirect cooks, and a full chimney for direct high-heat grilling. Weber’s owner’s guide instead sorts by grill size and method rather than target temperature. For direct cooking on a 22-inch (57 cm) kettle it lists 40 Weber briquettes, or 50 briquettes of other charcoal. For indirect cooking on the same size it lists 15 Weber briquettes per side for the first hour, and says charcoal typically lasts about an hour.
AmazingRibs ties amounts to temperature for a Weber kettle. A Weber chimney holds about 80 briquets. For 225°F (107°C) it uses roughly half a chimney of unlit coals with half a chimney of lit coals on top. For 325°F (163°C) it says three-quarters to a full chimney should do it. It stresses that air temperature, humidity and charcoal brand all matter, and that you should calibrate with dry runs. Its vent article adds that if the temperature slides, the best fix is to add fully lit coals, because unlit coals smoke heavily and push the temperature up as they ignite.
Troubleshooting From the Sources
Weber’s UK page has a short checklist. If the grill is not hot enough, open the lid vents fully, use fresh dry charcoal and clear away old ash. If it is too hot, check for too much fuel or air and close the lid vent slightly. AmazingRibs says closing the bottom vents a bit lowers a rising temperature, but not to shut them completely or the coals may die.
Safety and Limits
Weber’s owner’s guide says the vent and damper handles get hot and calls for heat-resistant mitts when adjusting them. To put the fire out, it says to close the bowl vent and lid damper with the lid on, not to use water. The sources cited do not cover a fire that has escaped the grill, so this guide does not either. If a grill will not hold a temperature in any vent position, AmazingRibs points to leaks first, and Weber points to clean vents, fresh charcoal and no leftover ash, before you conclude the grill is faulty.
Keep reading
- Lighting Charcoal With a Chimney Starter: Steps and Safety
- Grill Heat Levels: What Low, Medium and High Mean
- Snake Method vs Minion Method for Slow Charcoal Cooks
- Water Pans in Smokers: Where the Experts Disagree
Sources
- Weber (US) — How to Control the Temperature of Your Charcoal Grill
- Weber (UK) — How to control the temperature of your charcoal barbecue
- Weber — Charcoal Grill Owner’s Guide (document 57884)
- AmazingRibs.com — Using the Vents to Control Temperature
- AmazingRibs.com — How to Set Up a Charcoal Grill for Smoking or Grilling
- AmazingRibs.com — The Weber Charcoal Chimney