Depends on if the canopy is open in the back, or if it is vented in the top. If it is solid, then you may need a fan depending on how cool your house is.
Another factor to consider is if the ballast is inside the canopy or not. The ballast will add more heat than the lights will.
29gal BB | 42+ lbs LR
| 143watts PC
| Asst. Leathers, Frogspawn, Hammer, XLG Open Brain, Zoanthids, Mushrooms, Diploastrea heliopora | Blue Mandarin | Atrosalarias Fuscus | Pair Captive Bred Ocellaris Clowns | Peppermint Shrimp | 6 Astrea's |