The energy model allows calculating building energy usage and predicts the impact of improvements to various building components on the building energy consumption. To create an energy model you must describe the building on the screens of Building Model section. Complete the inputs on the Spaces, Walls/Surfaces, Heating/Cooling and Thermostat screens before attempting to run any model calculations.
Once you’ve described your building, click Calculate Model on the Feedback Panel. It is helpful to run calculations periodically as you work on the project inputs. Check the Feedback Panel and Model Energy Report to make sure that outputs change as you expect. This should allow you to catch and fix any input inaccuracy early.
- Once you start working on a section, you should fill out the screens in the order they are listed on the Project Index.For example, you must complete input on the Spaces screen before entering data on the Walls/Surfaces screen.
- However, some input screens may be skipped entirely.For example, you do not have to enter data on the Exterior Doors, Windows, Infiltration, Fans, Hot Water, Lighting, Appliances and Load Sizing screens in order to run the model calculations. On the other hand, incomplete input will affect the accuracy of your results. See information on each section for more details.
- Existing inputs can be accessed and edited in any order by navigating to the screen where the inputs were made.
- In general, the creation of a building model requires the use of several assumptions. Calculating your building model is the perfect time to make sure that your assumptions were reasonable.
Follow the procedure below to help ensure that the assumptions for your Base Model are reasonable:
- Run the Model Inspectorby clicking Tools -> Model Inspector on the main menu.The Model Inspector examines the data that has been entered for the base building and improvement packages to catch common data input errors. The verifications are general rules designed to check that the input data has a minimum level of consistency with a logical building model and with TREAT calculation algorithms. Review the warnings on every tab of Model Inspector and modify project inputs as needed.
- Check the Feedback Panel to see if the heating, cooling and base load calculated for the model is close to the billing numbers (if billing analysis was performed).
- Click the True-Up Help button for advice on how to reconcile the model and billing outputs.
- Review Design Heating and Cooling Loads Report to see that the load is distributed between the spaces as you would expect.
- Review the Model Energy Report to see that the building energy consumption and losses due to the different factors are reasonable.
Note: The model review can also provide valuable insight into what improvements should be proposed. The Evaluated Options section may only be used after the Building Model screens are filled out. Use the screens in this section to evaluate the effect of improvements on annual energy costs. You can run the Model Inspector for every package that you create.
Remember: The predicted savings are only as valid as the model of the Base Building.
The Building Inspection screens may be used to document results of visual inspections and measurements that were performed during the site visit. Inputs on these screens will not affect energy consumption of the model. If you are creating an energy model, it is wise to limit the inputs on the Building Inspection screens to items that do not influence energy consumption or may not be entered on the Building Model screens. If you do not plan to create an energy model for the building, then use the Building Inspection screens to enter all your measurements and observations.