Leaderboard

Wilbur is correct (and good call on Bernoulli, btw - brings back too many horror stories of derivations in grad school - shudder!!). I experience this a lot, as my grill is on an elevated deck (about 8 ft off the ground) and it sits between two houses that can channel the airflow, which is perpendicular to the lower vent. I can even lose control of the temperature using the Guru on a seriously windy day, which is another piece of evidence about the top vent being the dominate factor, seeing as the lower vents aren't open at all when using the Guru and the wind can't force air through the Guru port.