Heating and cooling load in a baseline model (DesignBuilder)

asked 2025-04-24 09:40:22 -0500

Fadwa's avatar

updated 2025-04-24 14:43:53 -0500

Hello everyone,

I’m working on an energy simulation using DesignBuilder (EnergyPlus engine), and I’m facing an issue I don’t understand.

My baseline model shows much higher heating and cooling demands than my proposed building, even though the proposed building has not been improved yet — it’s just the actual existing building without energy upgrades.

In addition, the baseline model shows more than 400 unmet hours, which seems unrealistic.

I expected the baseline to consume less or at least close to the actual building before applying improvements, but in my case, the baseline consumes much more energy.

I’m wondering if the problem comes from:

  • Construction materials not matching properly
  • HVAC settings or schedules
  • Internal gains or ventilation assumptions
  • Wrong zoning or infiltration values

Has anyone faced a similar issue? What should I double-check first?

Thank you in advance!

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Comments

Not a DesignBuilder (DB) user - simply raising a few questions, which may help experienced DB users:

  • your baseline refers to which standard, e.g. 90.1 2010 App. G?
  • any errors in (proposed vs baseline) eplusout.err files?
  • proposed & baseline sharing the same heating/cooling setpoint schedules?

... 400 UMH isn't unusual with sharp heating setback hikes, e.g. 18°C to 21°C in one timestep.

Denis Bourgeois's avatar Denis Bourgeois  ( 2025-04-24 14:43:10 -0500 )edit

Bu why do you want the baseline model to consume less energy than the proposed? The unmet hours denote there might be issue in HVAC settings.

Anurag_G's avatar Anurag_G  ( 2025-04-25 03:02:42 -0500 )edit