You need to use a certain amount of weed, in order to make sure that the heat passes through nothing but weed, because if there's a gap where there is less air resistance, it'll pass through that and not hit the weed.
If you're saying the hot air will take the path of least resistance and not vaporize the herb, the herbalAire disproves that.

trying to use a one hitter's amount of weed is not feasible for this reason
Sure is. You just need a vape with a small/narrow bowl. I've done lots of one hitters with a Vapolution. The Purple-Days can easily do it too.
vapefiend Reviewed by vapefiend on . The problem with vaporizers as I've experienced..... You need to use a certain amount of weed, in order to make sure that the heat passes through nothing but weed, because if there's a gap where there is less air resistance, it'll pass through that and not hit the weed. For instance, trying to use a one hitter's amount of weed is not feasible for this reason. It will eventually vaporize, but it's a long and annoying process. Rating: 5