This unit is manuf by Fujitsu. Air flow is critical to operation and efficiency. This unit is best, imho, if elevated at least several inches off the ground. I usually mount mine on a wall with wall mounting bracket designed for the purpose (www.rectorseal.com). For your comfort, happiness and the happiness of the unit, give yourself a couple feet at least. On a wall mount you can be within 6" of the wall, but that is clear air flow. I have seen these mounted on a small pad in a garden below and eve where the splashing water and dirt covered the face of the coil, which created a service call. Air flow is good! Nice unit, but I'd buy a Fujitsu before a Friedrich