I'd slap on a stick thermometer to check its temp. The ambient temp is going to be lower than ur actual fermentation temp (inside the fermenter)
Without building a cooler, there's not much you can do to keep it consistent. But if ur not too worried about it, u could simply throw some wet...
I bought the thermal controller from Coolerguys.com and 4-60mm high speed fans. I freeze milk jugs of water and change them out once they quit keeping it cool... All depends on how many carboys, what time in ferm, etc.
I just recently built a fermentation chiller that holds 4 buckets or carboys. I don't have any build pics, but here are some right after the build. Let me know if u have any questions. I'm no expert, nor do I claim the best build (just works for me).