Cooling My grow roommm NEEEDD HELP!!

I have a cabinet thats 2'8"Hx2'5"Lx1'D and i have a 400 watt hps unning in there the other day i turned it on for an hour to see how it works (havent started growing yet) and my room rose to 124F. Obviously unnaceptable.... I was wondering if i were to get a coool tube and have a 6" inline fan pulling the air out and exhausting it would it bring down the temp considerably? If not anyone got ideas?

Try a smaller light.you have 2.5 sq feet of space and limited height. a light will take up 4-6 inches & the plants need to be at least 6 in below the light(w/ a 400) so you will have less than 2 feet of height for plant and container.consider CFLs

A cool tube would bring it down, also there are cooled radiators made for the inline ducting that go to chillers. Room fans would help some as would a room a/c.

If worse came to worse you could get a water cooled light setup, you would need a localized water source such as a pool or resevoir, or a water chiller for this setup, but they work really well, they are pricy but not crazy.

Thanks guys im planning on doing a diy cool tube with one of those bake a round tubes only problem is i can only find them on ebay and i cant use ebay.... Anyone know of a place that hs detailed instructions on how to make one of these

dude honestly my local hydro shop sold me 2 cooltubes for 60$ each. they are super cheep. let me ask you some questions though , did you have your reader right under the light? if so your getting false readings. also do you have any fresh airflow into the area/room? like a window or air from another room? if not your just circulating hot air with nothing cooling it down. try reading about the basics of thermo dynamics so you can get a better understanding of how air cooling works.

if i turn off the fan that cools my cool tube my room goes from 72 to 120+ in ten min and i have an ac unit in the room, so your answer is yes. in fact your nuts for even plugging in that light in a sealed box without cooling it. remember this while you pondering buying a cool tube and a fan to push air through it, you cant buy a more efficient electric heater than your hid light.