Keeping a multi-story house cool using AC and attic fan?

[Martinjmpr]

After walking around in the living/dining rooms (which we rarely use, especially in Summer) I realized that the 3 vents were open in those rooms, making them very cool. I immediately closed all 3. Currently showing 76 in the kitchen (which is the hottest room on the main floor) with 98 outside.

I may try to close ALL the vents on the 2 main floors to force the cool air upstairs.

[Mercula]

I may try to close ALL the vents on the 2 main floors to force the cool air upstairs.

Might as well. It’s gonna come down anyways to some degree.
I’m probably going to try the curtain. Unfortunately my furnace does not have a fan only option.

Hopefully Highclasswhitetrash jumps in here with some experience.