Air conditioning surrounded by the house? In the night, the rooms get really hot, even though the atmosphere...

In the night, the rooms get really hot, even though the atmosphere is on. I'm not sure what's wrong with it. Is there a channel to make the rooms cooler during the night?
How much does it cost to run my...
Answers:    I am assuming the heavens is working in the daytime so you AC system is OK. IF the AC is working it sounds like roast from the attic that has built up during the daytime. If that is the problem an attic disciple would help a lot.