3 Ways Energy Models Add Value For Facilities Management
July 10, 2018 - Contact FacilitiesNet Editorial Staff »
Every facility manager has heard or experienced a horror story about engineers building a wildly inaccurate energy model for a new institutional or commercial facility. The energy model predicts a building will use a certain amount of energy, but when the real-world building goes into operation, it uses vastly more, causing finger-pointing between architect, contractor, and facility manager.
This situation often isn’t really anyone’s fault. To build the model, engineers need to make assumptions and guesses, such as operation hours of the building. Sometimes those assumptions just don’t bear out. The building is just open longer, so it uses more energy than the model predicted.
For this and other reasons, many managers are skeptical of the accuracy of models. Maybe a change in thinking about the role of the energy model is needed. An energy model shouldn’t be a be-all-end-all predictor of energy use in a building. Rather, managers should be able to use it to evaluate trade-offs and identify synergies between building systems.
Specifically, managers can use energy models in these three ways:
- Reduce equipment size. Modeling various building shapes, sizes and orientations, as well as the way they affect building equipment, can reveal that a smaller HVAC system will do the trick, for example.
- Find areas of largest impact. Doing comparisons of what-ifs shows the tipping point on the law of diminishing returns for energy decisions and, as a result, allows managers to make decisions based on strategies with the highest energy impact.
- Identify building performance relationships that don’t make sense. Energy models allow managers to discover that the “If some is good, more is always better” rule doesn’t always add efficiency to a building.
As building information modeling (BIM) gains prominence in the design community — and managers learn the ways BIM also can benefit them — energy models incorporated in those programs are becoming increasingly sophisticated. What’s more, as the integrated project delivery model also gains steam, assumptions about building characteristics become more accurate and representative of the way the building will function in the real world.
This Quick Read was submitted by Greg Zimmerman, executive editor, Building Operating Management. Read his Read his recent story about the way building Internet of Things technology is leading to a boon in net-zero energy buildings.