Less exhausting during night time resulted in less yield?

My first grow I was able to run my 590 cfm fan that exhausts my light/room on 24 hours. Now I am trying to keep temps high in my room so I tried turning off my exhaust fan while my light was off, I intake clean warm air 24/7 at like 350cfm. Running my exhaust fan 12 and 12 did a pretty good job at keeping temps as high as possible but my buds didnt fatten up like they did last time. What's the deal? I think by doing this while they were halfway through bloom may have stressed em too... What does RIU think? I think it plays an important role in simulating nature and may have harmed my yield because it was too 'fake'.

umm good one. it is so easy to drop yeild by 10 to 20 percent. any sort of plant stress no matter how low or high the stress. so maybee. but you can drop to as low as 55 degrees in flowering with out any stress. well that's from my experiences. what are youre night time temps

The reduction in yield could be attributed to just genetics, or it could be because you were not introducing new co2 into the grow area and caused the plants to just sit there in their own self made oxygen waiting for more co2