I can't really answer your environmental control questions. I might try to setup a way to heat the incoming air. Are you comfortable sharing what brand LED's ? How many watts/ft ? How many watts of CFL for flowering? What brand and color temp? What yield are you shooting for ? How are you...
I would be interested to hear how the LEDs perform in flowering. Veg is easy to beat HID. Flowering is the weakness of LED.
Thanks so much for sharing. Keep us posted on height and dry weight.