Thanks. I'll be curious to see if the 2 air handlers do the job. What is the cubic footage of the cave?Here’s what I know about them(which isn’t much)They are mini splits.They have an indoor air handler and an outside condenser and compressor.They supply heat and ac by circulating refrigerant.They do not require ductwork.They are very efficient in power consumption and the power company offers rebates.I was hesitant about using them but I was assured this was the smartest way to go.We’ll see.