Analyzing Model Outputs
Analysis of energy model outputs serves two main roles.
- Verifying the quality of the model
- Answering design questions and providing insights.
This section lists useful energy model outputs, and the following sections cover how to apply them to verify model quality and answer design questions.
Several outputs will be important for nearly every project:
- Electricity and gas consumption by end use - annual and monthly
- Peak electric demand by end use - monthly
- Energy cost by source - annual
- Air handler peak cooling and heating demand - annual
- Chilled water and hot water loop peak loads
- Unmet heating and cooling load hours
These additional outputs can also be useful when checking the quality of the model as well as with providing insights into building performance:
- Energy consumption by source - hourly or sub-hourly
- Air handler cooling and heating demand - hourly or sub-hourly
- Chilled water and hot water loop demand - hourly or sub-hourly
- Peak cooling and heating loads by component, e.g. walls, roof, window solar, etc.
- Air handler hourly data: supply air flow, outdoor air flow, supply air temperature, cooling coil load, heating coil load, fan power
- Chilled water and hot water loop hourly data: flow, load, supply temperature, return temperature
- Zone air temperature
Output reports that summarize inputs and equipment capacities are useful for verifying the model and are produced by some simulation programs:
- A list of zones that summarizes load inputs such as lighting power, occupant density, plug load, and floor area
- A list of envelope components with performance values such as U-factor and SHGC.
- Description of air handlers including autosized airflow, cooling capacity and heating capacity as well as efficiency.
- Description of chilled water and hot water loops including autosized capacity and efficiency.
Review and analysis to verify model quality
Even a simple box model presents many opportunities for unintended inputs. An output review can help verify model quality and confirm that the model represents your intended inputs
Analysis to provide answers and insights
BEM can be extremely effective at providing guidance on design decisions throughout all phases of a project, and at developing strategies to meet performance targets. An overview is provided below, but for much more detail and guidance on using BEM to inform specific design tasks, please visit the Learn by Design Task section of this site.
- Overview: Analysis to provide answers and insights
- See also:
Presenting the results
Energy modeling results have little value if decision makers do not understand them. When presenting results to owners and design teams here are two recommendations.
- Focus on answering design questions rather than presenting simulation results
- Present information visually
The overview below includes several examples of energy model results presented graphically but for much more detail and guidance on presenting results relevant to specific design tasks, please visit the Learn by Design Task section of this site.