ventilation question

I bought a 250 watt lamp that has a four sided reflector. how am I gonna work out the ventilation with that?

Got a pic? Do you mean it's a standard style reflector but just doesn't have any place to connect ducting?

there's not much you can do, the best thing i would say is hang a fan about the same size, at the same height has the light. that should offer some ventilation

What you need to work out is the ventilation for the size of your grow room, not the light. Vent the heat of the room with ducting and an in-line fan (for example) but have an oscillating fan blowing just below your light so it doesn't heat up your plants. Its all about circulation.