hi I Have A Grow Space Thats About 3ft High 4ft Long And 2ft In Depth And I Hav A 600watt Hps Light In Ther And It Gets Really Hot In Ther I Hav A Fan In But Only Seems To Help A Little Bit Is Ther Eny Thing Eles I Could Do To Cool It Down
Only thing you can really do is make your ventilation more efficent. Have one fan blowing cool air in, one blowing hot air out, and keep any leaks sealed.
Yes You need an actual exhaust fan sucking that hot air out. Try a 256 CFM fan from Home Depot or somewhere and hook that sucker up to some PVC pipe or something and suck her out.