Floor ceiling units resemble what you might see in a hotel. They are mounted against the wall, on the floor, or on the ceiling by an adjoining wall. Floor ceiling units are good for workshops, detached sheds, and other areas where a traditional wall mount just might not be the best fit. They are also very popular for temperature and humidity control in greenhouses and come in a variety of sizes from 12,000 BTU up to 48,000 BTU.