Temperature: Difference between t5 - t8 or t12?

I have experience with t5 but never with t8 or t12 for veg cycles. My question is what floro runs at a cooler temp (not in spectum!)? I just want a cooler bulb cause I'm ending up putting my mother room in my veg room. I'm trying to do everything green for the environment and want to be energy efficient.

I have no experience with T5 or T8's...but T-12's..(6500k) are cool to the touch. Seedling leaves can touch the bulb...no problem.

I use T-12's the first 3 weeks....and keep it within 2 inches of leaves....(I had to raise it for the pic)...:pimp:

I'm using two t-12 ballasts right now, and I've used the t-8.

Used cool white bulbs only in the t-8 with disappointing results. I'm using one full spectrum (but heavy on the cool white) daytime bulb in each t-12 ballast, and one full spectrum (heavier on the warm red) sunlight bulb. The t-12's with two types of full spectrum bulbs in each ballast are blowing the t-8 away. Will definitely use the t-12 again next time. Growth is fast and healthy.