A: Here’s the deal: Warm air rises, right? Moreover, this is also one of the reasons why it’s important to rotate your cigars from time to time. Placing the humidifier anywhere cigars may touch or be too close to the unit may be detrimental to those specific cigars, which is why under the lid is the most logical place. As long as there is good air circulation, the cigars should be fine, regardless whether the humidifier is above or below. I’ve read reports of cigar smokers adding fans to the their humi’s to circulate the air. Speaking of which, you might be better off getting a Cigar Oasis XL which will accommodate most medium and large humi’s, plus it has a built-in fan to circulate the air.
Secondly, a 2-3% difference is not all that big a deal. RH fluctuates regardless of how reliable your gear is.
Except for a glass top unit in which I have a humidifier on the bottom and a small jar of gel crystals, all of my humidors have the humidifiers under the lids, and they’ve been keeping my cigars fresh for years.
Thanks again for pointing this out, and I hope others read the Robustojoe article, too.