Temperature issues

Recently finished building out my grow room in a new house. Temperature is higher than I'd like, about 83F during light cycle and 73F during dark (basement ambient temp is 72-76). Outdoor temps are 60-80F generally. I've done a lot of growing in tents in the past but wanted an entire room.

Here are my room specs:
8'L x 6'W x 7.5'H enclosed room in the corner of my basement, fully insulated, drywalled, edges caulked. Running ~800W (rated) worth of LEDs, a 40in carbon filter and 720cfm fan exhausting outside of the room. The filter/fan sits upright in the corner. Two ebb n flow systems- 25gal thick-walled totes underneath metal frame shelving, each with water and air pumps. Also, one oscillating pedestal fan.

Is there anything I can do to bring down temps a little without resorting to AC? Maybe mount the filter/fan horizontally to the ceiling? Should I not have insulated the walls? I have a feeling temps might be perfect come winter time, but a bit too high for summer. TIA for any recommendations.

Where is the air coming in from and where is it being exhausted to? You said it is being exhausted outside of the room, but you mean like within the basement or directly outside? You wanna make sure that the hot air is being sucked out and away from where ever the air is going into the room.

Run the lights at night which I assume youre doing, and try to get the cool air at night to be passed through the room (through filters) via intake and exhaust fans.It's best if you can get a duct to bring the air from outside instead of passive intake of basement air if the basement temps are already in the 70s. If the air youre trying to cool with isnt cooler than what you want the room to be then there isnt anything else that will drop the temps besides AC.

There are 2 4" circular vents bringing air in. The negative pressure pulls in that air pretty fast so I've not added any fans to them. Exhaust runs through flexible duct to the opposite corner of the basement, about 20 ft away. I run lights during the daytime since I work thirds and would rather be around if there's any issues during the light cycle.

In terms of temps, some nights it gets down to 60, but others it's 75+ (Midwest weather, Ohio specifically), so I don't think I can count on bringing air from outside during summer. The majority of the basement is 72-74 most of the time, so 83 in the grow room just seems like a big jump to me- especially since I'm using a relatively high powered fan for a small room.

Hey fick, sounds like you're using passive intake if I read this right, the temp difference between ambient and your room aren't that bad. To cool it further you either need more/faster inbound air from the basement (72-74) or suck air out faster. Bringing in cooler air is usually the easier and better of the two. An Inline fan with a variable controller on an incoming vent would allow you to bring more air in and adjust it depending on the season using the variable speed controller. Only other alternative is AC. But if temps max out at 83F through the summer that's not terrible, there are folks who would love to have that be their max temp. My flower room peaks during lights on at about 83F for a couple of hours before lights off, down to 70F lights off, for summer growing I consider that normal and acceptable. I could bring it down a bit by cranking up my incoming air inline fan but those temps work fine for me so I don't worry about it. Winter I have to heat in that same room, it's in the basement and insulated as well.