We recommend that you place your unit at least two feet off the ground for the sake of keeping the unit running as efficiently as possible. This unit works to raise the humidity in the space by producing a mist that will collect with the particles in the air. The higher up the unit is the more time the mist has to collect with those particles before falling to the ground. If the unit is too close the ground, we can see a puddle around the unit which is of course a safety hazard.
We do recommend against putting this unit directly onto a wooden surface. We will always suggest placing down a waterproof barrier under your item to protect your wooden furniture. Examples of waterproof or water-resistant surfaces include plastic, tile and glass. Some customers like to use things like plastic place mats, cutting boards, or plates. This is similar in concept to putting down a coaster under a glass to protect a wooden table.