I've never grown orchids under lights, so I don't know about that. Are they plant lights?
I would either be sure you have plant bulbs or move your phals closer to the window. I wouldn't put them any closer than a 1' 1/2 from the window. The temp. on a windowsill is too unstable for a phal. I like to see the sun hit my orchids for at least two hours a day. Phals should get morning or evening sun because they will sunburn easily in direct mid day sun. Southeast is good as long as its not blocked with too many trees or a big eave.
Good luck!
Happy to help.
-Lizzy