Hi Chris,

Per the Manual J book, we use table 4E to determine the temperature difference between the attic and the floor below it when "encapsulated attic" is chosen for the ceiling type. I have attached a copy of the table. In general, the table assumes that the attic is going to be about 4-5 degrees hotter in the summer and 4-5 degrees cooler in the winter than the space below it.

Best Regards

Bill