As part of the existing building commissioning (EBCx) workshop (check out our previous entry about this workshop provided by PG&E) we took a technical exam and an excel exam to help the instructors, Ryan and David, understand our current knowledge of building systems and where the class may be strongest/weakest moving forward. Understandably, it’s hard to teach a technical class if the knowledge base of the intended audience is too far below the material being taught. It was an important, albeit slightly nerve-wracking (my computer froze during the excel exam portion, cursed excel!), 1st step which also helped self-assess where we were in terms of our peers and what we may need to put some additional time into during the class. The first learning session focused on benchmarking a building and analyzing smart meter utility data.

Benchmarking Basics:

Benchmarking is a tool that can be used to assess if energy consumption saving opportunities may exist in your building(s). How is a building performing right now compared to its previous history and other buildings like it? ‘Other buildings like it’ are those which are similar in type, climate, size, and age. If the data shows that the building has done better, or could do better, then there is probably an opportunity for existing building commissioning to help optimize building performance. Our first homework assignment of the workshop was to benchmark our building. The online resources which helped us were:

Energy Star Portfolio Manager
Department of Energy’s Building Performance Database (BPD)

Both of these resources are free to use after creating a user profile and are already populated with useful data. For our purposes we gathered 3 years of gas and electrical data provided by the installed smart meters at our jobsite or directly from the utility provider itself. The energy star portfolio manager plots the utility data by calendar month as seen for our (2) building samples below. It also calculates the baseline (initial data set) and current (latest data set) source EUI, site EUI, energy cost estimate, energy star score, and the change of those variables over time. Ideally, with ongoing maintenance and commissioning, the utility usage should remain pretty consistent year to year as long as the building hasn’t changed its operation.

Energy Star Building Profiles:

Building 1 Energy Usage: Electrical consumption remains relatively flat throughout the year, gas consumption is seasonal due to the building systems operation.

Building 1 Energy Metrics: Source EUI (Energy Use Intensity) reflects the overall energy usage, taking losses in production and distribution into account, for a building in operation. Each metric degrading over time is an indicator that building performance may be improved by existing building commissioning.

Building 2 Energy Usage: Each utility slowly increasing over time is an indicator that building performance may be improved by existing building commissioning.

Building 2 Energy Metrics: Site EUI reflects the amount of gas and electricity consumed by a building as captured by the utility bills.

Then using the Department of Energy’s building performance resource it’s easy to analyze how your building compares to a building dataset similar in type, climate, size, and age. Using these (type, climate, size, and age) variables within the BPD tool you can narrow down the dataset to best compare your building. Our buildings were found to be operating on opposite sides of the median when compared to our separate datasets of similar buildings.

Benchmarking can help determine if your building is an energy consuming outlier and/or if money is being lost in operations over time due to degrading building performance. Contact us if you need help benchmarking your building(s) or reading your utility data. In our next EBCx workshop blog we’ll get into analyzing utility data in further detail.

Department of Energy Building Performance Database Building Profiles:

Building 1 Source EUI: Performance is slightly better than the median EUI in the unique similar building dataset.

Building 2 Source EUI: Performance is worse than the median EUI in the unique similar building dataset. This is an indicator that building performance may be improved by existing building commissioning.