Hello Sergio, for me, I was always able to get the desired temperature just by finding a balance between the exhaust and circulation fan.
My takes would be:
- More powerful exhaust
- Limit the circulation fan power (sometimes I had problems with too strong air circtulation inside of the tent, because it was also taking the heated air from the light back down to the plant)
- Enrich the CO2 in the environment. With a proper light, watering and nutes, the CO2 enrichment can make the plant work better even with a bit higher temperatures.
Wish you luck :)