The formula detects unreliable systems and faulty equipment that affects energy consumption, researchers said.
Li Song from University of Oklahoma and her research colleagues, Gang Wang from University of Miami and Mike Brambley from Pacific Northwest National Laboratory, have invented a method that can significantly reduce building operating costs as well as energy consumption.
Her applied research has potential to reduce energy consumption in a single structure by as much as 20 per cent.
Depending on the building conditions, Song estimates peak savings could be as much as 30 to 50 per cent.
Song's research team devised a mathematical formula using existing output data, such as pump speed and power, to monitor energy use in heating, ventilation and air conditioning units.
Based on the results, the formula detects unreliable systems and faulty equipment that affects energy consumption.
Song's formula creates virtual sensors to identify energy waste at the air-handling unit as well as at a whole-building level.
"Waiting until exorbitant utility bills appear may be a sign that the equipment hasn't worked optimally for years," said Song.
"This method allows earlier detection of minor equipment faults, possibly preventing an overhaul of the entire system," Song said.
Besides saving companies money on utility bills, Song's formula is a low-cost option to commercial monitors, making it easier for more companies to track energy efficiency.
Song estimates one ultrasonic flow meter, which monitors water pump performance, could cost as much as $5,000, and an organization would need to buy several monitors to get an accurate picture.
Song's virtual process uses little to no hardware and is within two per cent uncertainty ranges compared with commercial meters.
Prior to developing virtual sensing, Song implemented the energy monitoring and operation fault detection and diagnosis manually in more than 100 buildings with cumulative savings exceeding $70 million.
In one building alone, her method reduced annual electricity consumption by 53 per cent, electricity demand by 21 per cent and gas consumption by 49 per cent in one year.