"He who marches out of step hears another drum." ~ Ken Kesey
What dryer are you running? When we only had a workhorse 3011 it was super comfortable. with the Raypaul it's a min. of 80 degrees with the air running.
We do tons of garment dyed shirts. 30 foot ceilings are still not high enough. The smoke/fumes from the dye is terrible. I would go for the high ceilings.
we have AC and low ceilings. You will have minor problems with the small electric dryer. If you wrap it well, you should be OK and it should not impact your electric bill much. discharge and small enclosed space do not mix, you will have to ventilate so all your cold air will be gone!Shorter ceilings are better as the air volume is lower so it will cost less to cool and it will recover faster if you have to blow the fumes out. With both the small and the large dryer we ended moving the output through the wall into the warehouse. You will need a way to manage the smoke/fume output. Make up air is the way to go if you are building your own.pierre