Building energy efficiency is gaining a lot of attention for its ability to help dramatically reduce carbon emissions and unnecessary energy expenditures. Energy efficiency retrofits and upgrades have the potential to save large building owners millions of dollars over time – but not all efficiency upgrades are created equal. It takes a lot of specialized expertise to know which ones will deliver the kinds of returns that will make them worth the investment. Because capex funds are in such high demand and decision-makers can be apprehensive about signing on to anything but a sure thing, efficiency improvements are often delayed or tabled for another time.

But ignoring energy efficiency out of a fear of making the wrong decision is a choice that can cost building owners big money over time. Every month that a strategic energy efficiency project is delayed is another month of paying too much (sometimes way too much) in energy costs. But there is a way forward. Overcoming project inertia begins with developing a better understanding of building systems, their individual energy profiles and the ways in which they impact each other’s processes. This information is key to creating a strategic energy management plan that addresses both energy use and cost savings and leads to better operations overall.

A good place to start building a roadmap is to understand, in general, which building systems use the most energy.

(Source: https://www.energy.gov/sites/prod/files/2017/03/f34/qtr-2015-chapter5.pdf)

By looking at this chart, one may assume that energy efficiency projects should begin with HVAC because the biggest returns must be found in optimizing the biggest energy-consuming system, right? Not quite. In fact, the exact opposite is true. Even though HVAC uses the most energy, upgrading HVAC systems should be the last step in what energy.gov calls the “staged approach to building upgrades.”

(Source: https://www.energystar.gov/sites/default/files/buildings/tools/EPA_BUM_CH9_HVAC.pdf)

…[A] 1 watt per square foot (W/ft2) reduction in lighting load in a 100,000-ft building would allow a chiller capacity reduction of about 23 tons (assuming 80 percent of the waste heat reaches the conditioned space). If a typical chiller costs $450 per ton, then a 23-ton reduction would reduce the first cost of a new chiller by more than $10,000.

According to energy.gov, the majority of buildings in operation today were built before 1970. This means, in general, the efficiency of individual building systems is all over the map, and there is no true one size fits all approach that can be applied without a deep dive into the specifics of each individual building. Because of this, it pays to consult with an energy efficiency expert to help you create a project roadmap that will result in the best possible results.