Yep, I learned that same lesson the hard way too. I always turn off the fan before I take a dab.Man I'm a fucking idiot and having a great laugh about it.
All summer I was having trouble with flavorful extraction from the vrod and b2 sic dishes. Sometimes concentrate would just vanish into it, I'd see vapor come off in loads but I'd get very little vapor from inhaling. I tried playing with temp, went up to 700 and have slowly started walking it down, thinking there was poor conductivity or something between coil and dish which necessitates higher temps. Today, I'm at 640, and did a dab and this time noticed that hardly any vapor came off the dish before i got the cap on. Then it hit me. Fucking moron that I am, I've had the god damn ceiling fan going the whole time because, well, summer heat waves. That was constantly blowing on the dish and cooling it, and also creating the turbulence to displace so much air that the vapor would flood out (well that's my theory anyway)
today the fan is off because it's a nice 69 out. I took a hit expecting poor vapor but instead got the flavor and vapor I've been missing for so long