It’s supposed be an all in one heater,a/c, dehumidifier..you can utilize a neutral, positive or negative air pressure depending on your need..

It’s best to let it sit upright for a couple of days just to make sure the oil and refrigerant is good and settled before you crank it up because you don’t know if the delivery services had it upright the whole trip to you or if it had been sitting on its side or something and then it burns up the compressor when you crank it up