Carrier HAP

Hourly Analysis Program. costs like 2k a year. Version 6.X uses energyplus under the hood, 5.X and before was developed by carrier. Energy plus is a heat balance model which just means that rooms have heat transfer between each other, while the carrier model was a simplified method that modeled each room as its own space.

You make "levels" which aren't necessarily floors, you can have two levels be adjacent buildings of the same property.

You import a pdf of a floor plan then sketch over it. Then you can import that perimeter to the floor above. Seems really easy.

stub walls are neglected when software renders (so walls must be connected to something else).

Vertically, you can't have 2 different wall materials in a level.

You can have an "air wall" where you have multiple conditioning zones in a large space but this makes them all the same "radiation" space, so this is bad for hallways. I guess the solar heat gain gets distributed evenly.