Model Refinement enhances model accuracy by constraining key parameters to match verified performance characteristics. This helps create more alignment between the model and real-world performance.
Suggesting Changes from Documents
Rather than entering targets by hand, you can hand Carbon Signal the documents you already have. Click Suggest changes on the building details page, upload up to 5 files of no more than 4.5 MB each (PDFs up to 100 pages), and Carbon Signal reads them and proposes model refinement targets. Review the proposed targets and accept the ones you want; nothing is applied until you accept it. This feature is enabled per deployment, so it may not appear on your account.
Model Refinement for a Single Building
To access Model Refinement, go to the Building Details page and click the Energy Model page tab. A new building starts with a preset set of targets, chosen from its building type, location, and the data available for it, so the number varies from building to building. Each section header carries a pill showing how many targets it currently holds.
To set more targets, click the Edit button. Every parameter is listed on the tab, grouped into collapsible sections that show how many targets each one currently holds, so there is no separate button to add one. Expand a section, set a value on the parameter you want to constrain, and select a confidence level (Low, Medium, or High), which determines how strongly the input influences the model results.
The tab holds roughly thirty building characteristic targets, grouped into nine collapsible sections:
- Process loads
- Refrigeration
- Heating & cooling plant
- Building envelope
- Lighting
- Equipment
- HVAC distribution system
- Ventilation system operation
- Heating & cooling setpoints
These cover parameters such as window and wall thermal performance, window heat gain, window-to-wall ratio, infiltration rate, lighting and equipment power density, ventilation rate, heat recovery effectiveness, supply air reset, fan pressure drop, fan minimum turndown, heating and cooling systems, refrigeration load and efficiency, setpoints, and per-utility process loads.
Each parameter shows its characterization alongside the input: a distribution across the range of values Carbon Signal tested, showing which values the calibrated ensemble actually carries. Setting a target and a confidence level narrows that distribution toward the value you provide.
Additionally, a tenth section, End use targets, lets you constrain how energy is split across end uses. This is especially useful if the building is sub-metered and you have data on how much energy goes to specific end-uses like cooling or equipment. There are two kinds:
- End use share target – specify the percent of total energy use for the selected end uses.
- End use intensity target – specify the combined annual energy intensity, in kBtu/ft², for the selected end uses.
You can apply an end use target to any of the following six end uses:
- Heating
- Cooling
- Lighting
- Equipment
- Pumps & Fans
- Refrigeration
Each target needs at least one end use, and can combine several. For example, if the building only sub-meters heating and cooling together, you can put both into one target.
A maximum of five end use targets can be added per building.
After you’ve set the value and confidence level for each target, click Save. The model will then incorporate those assumptions into its calibration process, producing results that more accurately reflect your building’s systems and energy use.
Model Refinement Across Multiple Buildings
Model Refinement can also be applied across multiple buildings at once. Users can update building characteristics in bulk, allowing consistent assumptions to be enforced across a portfolio without refining each building individually.
To apply Model Refinement to multiple buildings:
- From the Buildings page, select the buildings you would like to apply model refinements to by checking the corresponding boxes.
- When the action bar appears, click More actions.
- Select Update model refinements.
This opens the Adjust model refinement modal, where you can add or remove building characteristic targets across all selected buildings.
Adding Building Characteristic Targets
- In the modal, ensure the Add targets toggle is selected.
- Expand the section containing the building characteristic you want to set. Every parameter is listed, so there is no separate button to add a target.
- Set the characteristic value and confidence level on that parameter, using the same inputs as for a single building.
- Click Save to apply the target to all selected buildings.
Removing Building Characteristic Targets
- In the modal, ensure the Remove targets toggle is selected.
- From the Targets to remove multiselect, choose the building characteristic targets you would like to remove.
- Click Save to remove the selected targets from all chosen buildings.