Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
The key thing to point out for the Ideal Load Air System is that it provides heating and cooling at perfect efficiency, which real HVAC systems cannot do. As such, energy consumption will always be less for the Ideal Load Air System compared to a real HVAC system maintaining the same conditioned air states -- unless you model an HVAC system that breaks some laws of physics and thermodynamics!!!
Both cases should have similar unmet hours as long as key system parameters -- capacity, supply air conditions, availability, etc. -- are the same between them.
Primarily, the Ideal Load Air System is used as a load calculation tool -- get everything else except HVAC set up in the model, then see what kind of heating and cooling loads each zone requires in order to design the real HVAC system.
