i just ordered my 400 watt hps and it will hopefully be getting here shortly and they way it looks i would be able to put the ballast outside of the room.Is this something that would be good? Does ballast put off heat?

Anything with power running through it puts off heat but i don't think it'll be noticeable next to the heat of the light. If you can put it safely out of the room then this is good because you are less likely to trip over it or something.

yea I have to say the ballast get warm to thw touch. But to solve this I just put an extra fan on IT BLOWING.

That's a good idea, keeps the risk of electrical fault down.

Ballasts are extremelly hot (except the digital ones) they are responsible for generating a great deal of heat, that´s why in HID lamp systems used to grow indoors usually u have a remote ballast, so u can put it outside the growroom...(unless the room is to cold)

thanks guys thats what i thought i wasnt real sure