4.0 Working With Projects

4.1 Billing Analysis

TREAT allows calculating average non-HVAC (base) load and heating slope (building heat loss rate) by analyzing utility bills alongside with daily outdoor temperatures during the billing periods.

You may chose to obtain utility bills and run billing analysis before going to a site visit to get a better idea about the energy performance of the building.

Billing analysis is also a valuable tool for validating the building energy model by comparing the modeled results to actual billing information.

As with any statistical calculations, it is important to have large amount of reliable billing data available in order to get meaningful results. We recommend that you have at least twelve actual utility bills available for each analyzed fuel. If a fuel is used for both base and HVAC load, then the bills must be available for the months without noticeable heating and/or cooling.

You do not have to create a building energy model to run billing analysis. Use the Run Billing Analysis button on the Analysis Periods screen to run calculations for the analysis periods that are not compared to the model.

The Heating Energy Scorecard and the Investment Guidelines for Heating reports show the results of billing analysis performed independently of the model. The Heating Energy Scorecard report demonstrates how your building performs relative to other typical buildings. The Investment Guidelines for Heating report calculates cost effective investment for specified target heating energy consumption and payback.

TREAT normalizes billing data based on the calculated heating and cooling degree days per time period.

TREAT does not perform regression analysis of the bills. The user has to specify heating and cooling reference temperatures if billing analysis is run independently from the building model. In this case the accuracy of the billing analysis strongly depends on the reliability of the assumptions.

To run billing analysis, fill out the screens in the Billing Data section. Skip the Metered Spaces screen for projects where usage of each fuel is measured by a single meter. See the Billing Data section for more details.

4.2 Energy Model

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 model calculations using the Calculate Model button 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.

Tips

  1. 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 Spaces screen before entering data on the Walls/Surfaces screen.
  2. 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. However, incomplete input will affect the accuracy of your results. See information on each section for more details.
  3. Existing inputs can be accessed and edited in any order by navigating to the screen where the inputs were made.

After you complete the model inputs, run the Model Inspector and review the Feedback Panel, Model Energy Report and Design Heating and Cooling Load Report. You probably made many assumptions to create the model, and now is the time to check if the assumptions were reasonable. It is useful to complete the review as outlined below before making any changes to the model.

  1. Run the Model Inspector by 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.
  2. 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.
  3. Review Design Heating and Cooling Loads Report to see that the load is distributed between the spaces as you would expect.
  4. Review the Model Energy Report to see that the building energy consumption and losses due to the different factors are reasonable.

The model review should not only help you to verify the Base Building model, but also provide valuable information on 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.

Tip

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 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.