I used to start out with as low as 12 on the 22.5 WSM depending on the weather. More charcoal will get you up to temp faster. Using less allows you to more of a window as you have to wait until more charcoal in the bowl gets lit to get you up to temp. Make sense? Once you get a better idea of what you need for a certain temp you can start out with more charcoal lit from the beginning. Like others have said, catch the temp on the way up. I usually leave the vents open and start shutting the bottom ones down when I hit 200. The 22.5 likes to run hot so I would have usually 2 vents completely closed and one open a sliver. With beef ribs, I suggest running hotter. The bones will protect the bottom of meat and you'll render more fat at 275 to 300. More airflow will give you less smouldering chunks.
If your temp massively overshoots don't be afraid to cut back the top vent some. I would never got past half and usually open 75% makes a big difference on that. Ideally, you run with the top full open.
If your temp massively overshoots don't be afraid to cut back the top vent some. I would never got past half and usually open 75% makes a big difference on that. Ideally, you run with the top full open.