Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
In simple HVAC mode, many fields—like seasonal COPs, fan static pressure, and auxiliary energy inputs—are often overridden or ignored if the simulation is not fully engaged with detailed system modeling. The key setting you’re likely overlooking is the “ideal loads” option, which simplifies HVAC to zone-level heating/cooling without accounting for system performance or fan/pump energy. When ideal loads are active, it bypasses equipment efficiencies, fan curves, and auxiliary settings entirely. To make your COPs, fan static pressure, and auxiliary kWh/sf meaningful, you need to disable ideal loads and assign a full HVAC system template with non-idealized performance modeling.
| | 2 | Suggested edit |
In Here’s the deal: when you’re running HVAC simulations in simple HVAC mode, many fields—like seasonal a ton of critical fields—seasonal COPs, fan static pressure, and auxiliary energy inputs—are often overridden or inputs—get ignored if the simulation is not fully engaged with detailed because the model isn’t actually simulating how the system modeling. works in detail. The key setting you’re likely overlooking is main culprit? You’re probably using the “ideal loads” option, which simplifies HVAC to zone-level heating/cooling option. Ideal loads is great for quick, high-level estimates because it just provides whatever heating or cooling a zone needs, without accounting for system performance simulating actual equipment performance, fan energy, or fan/pump energy. When pump loads. That means all those numbers you’re trying to dial in—COPs, fan curves, auxiliary energy—they’re basically meaningless until you switch off ideal loads are active, and set up a proper HVAC system with realistic equipment specs.
To get results that reflect real-world energy use, you’ve got to define a full HVAC system: pick templates that include actual equipment, with non-idealized performance, so the model can account for things like fan power, part-load efficiency, and so on. It’s a bit like appliance repair—you don’t just assume your fridge or washing machine works perfectly forever; you have to look under the hood, deal with worn parts, and tune it bypasses equipment efficiencies, fan curves, and auxiliary settings entirely. To make your COPs, fan static pressure, and auxiliary kWh/sf meaningful, up for actual conditions. Same principle applies here. If you need to disable want outputs that stand up to scrutiny (or to energy code review), ditch ideal loads and assign a build the full HVAC system template with non-idealized performance modeling.system.
