The word I got from my mentor is "if it's a Den, put it outside if at all possible !!!" Everyone of mine perked right up when I followed his advice ! I leave them out as long as possible in the fall. While inside I keep them with all my others under lights and in a SE window. They like to drain fast, dry out between watering, and become potbound. HTH.
Bob, the oncidiums will take great to S/H. They like more light than phals, and lots of water when they are growing. You'll be blooming them in no time.