By JOHN GALYEN, President, Danfoss North America

Nationally, talk of doubling U.S. energy productivity by 2030 is growing louder. Representing nearly 36 percent of U.S. electricity consumption and 21 percent of primary energy consumption, existing buildings are an ideal target in the pursuit of greater energy productivity.

Fortunately, the energy performance of buildings is expected to improve significantly in the decades ahead: From 1980 to 2009, for every 1 percent of growth in U.S. commercial-building space, primary energy consumption increased 1.19 percent; from 2009 to 2035, the U.S. Energy Information Administration estimates, for every 1 percent of growth in U.S. commercial-building space, primary energy consumption will increase only 0.79 percent.

How will those predicted energy savings be obtained? Through the many proven technologies available today, such as variable-speed … everything.

With HVAC equipment accounting for 40 percent of commercial-building energy consumption, substantial reductions in use can be achieved with mechanical equipment capable of modulating capacity and lowering speed, such as variable-speed compressors, fans, and pumps. Variable-speed equipment provides the additional benefit of enabling systems to better match capacity to demand to operate efficiently at part-load conditions.

For example, on one project, two 150-ton chillers were replaced with one 150-ton variable-speed chiller, which improved efficiency 42 percent.

Variable-speed technology not only improves efficiency, performance, and comfort, it helps to address peak-demand concerns, allowing utilities to control the speed of a unit intelligently and minimize impacts on occupants.

At the 64-story U.S. Steel Tower in Pittsburgh, installation of more than 150 variable-speed drives for domestic-water supply and fan and pump motors over a nearly 15-year period produced annual energy savings totaling more than $1.1 million (see “VFD Retrofits Lower Skyscraper’s Energy Consumption,” December 2016). The variable-speed technology aided participation in demand-response programs, while the 34-percent reduction in energy consumption enabled the property-management company to obtain rebates from the local utility.

Imagine the possibilities if variable-speed technology were deployed on a greater scale.

Moving to “variable-speed everything” is a step on the path to doubling our energy productivity and making our buildings more sustainable. To encourage the broader deployment of variable-speed technology, we need supportive regulations and standards and the right package of incentives.

We’re on our way, but the journey is far from over.