Monitoring Utility Usage Can Save Owners Thousands
Imagine that you’ve driven a car for years and you routinely get 20 miles per gallon of gasoline. Now imagine that number starting to dip down to 15 miles per gallon. You aren’t likely to ignore that: Something is wrong, something has changed, and you’re going to fix it because it’s costing you money.
The ability to see similar changes in utility usage at a healthcare facility can save thousands of dollars—and that’s where a utility usage dashboard tool can make a real difference.
The University of Kansas Hospital began planning for a new medical office building (MOB) in Kansas City, Kan., in 2008. The hospital selected Burns & McDonnell (Kansas City, Mo.) to prepare the mechanical, electrical, and plumbing engineering design for the project. The engineering design was completed in 2009, and construction was completed in 2011. The 216,000-square-foot building went on to earn LEED Silver certification from the U.S. Green Building Council.
As part of the energy use verification services provided for the facility, Burns & McDonnell developed and implemented an energy dashboard. The Web-based dashboard provides real-time readings on use of electricity, natural gas, and water in the building, which has now been in operation for two years.
Meters were placed throughout the building to measure utility usage. The data from the systems feeds back to the dashboard and is tied to the building automation system. The dashboard provides a simple real-time readout of actual utility usage, with each gauge also indicating predicted usage and daily peak usage levels. At a glance, it’s possible to see utility expenses, plus savings (or excess) relative to the baseline expectations. The results are displayed in both dollars and the relevant units.
After the initial investment in setting up the equipment, the only recurring expense for the dashboard is updating current blended utility rates. Since most utility companies include various charges, taxes, and fees on invoices, this system breaks that information down into a simple cost per unit on a monthly basis, making the dashboard’s savings calculations as accurate as possible.
In order to determine those baseline values, an energy simulation of the building was generated. It models the thermal qualities of the facility and takes into account when the building is occupied and such details as when lights or equipment are expected to be in use. It adds models of the heating and cooling systems and reflects the efficiencies of chillers, boilers, pumps, and associated equipment.
The program performs a minute-by-minute simulation of outside air temperatures, determines whether lights are on or off, and predicts other factors such as building occupancy. The program then calculates what the heating and cooling values should be at that time. One of the complications of creating the dashboard for the MOB project was that standard energy simulation software uses average weather data, so the challenge was to factor in predicted utility use based on actual outside temperatures. An algorithm was developed to calculate expected energy usage based on current weather conditions as well as day type (weekday versus weekend, start of the week versus mid-week or later) and time of day, an attempt to create a better benchmark than a simple average or approximation.
Making a case for savings
The simulation-driven baseline lets an operator observe efficiencies and see whether the utilities are performing to expectations. The dashboard offers insight into what utility consumption means from a cost or usage standpoint, and it provides the potential to identify savings opportunities or troubleshoot unexpected readings.
Upon completion of the MOB, The University of Kansas Hospital began trending its utility data in the facility. An interesting pattern developed fairly quickly: the electricity usage was significantly higher than anticipated.
It was deduced that the reason for this was the original simulations for the facility assumed the building would be closed from 7 p.m. until 7 a.m. and would allow the thermostats to set back to a cooler or warmer temperature depending on the season. It also assumed the lights would be off at night. But the way the building was being operated, the lights were being left on all night and the HVAC system was being left in an “occupied” setting, maintaining the day temperature set points.
By calculating the overall energy use for both predicted and actual conditions, the dashboard made it possible to justify an appropriate fix that proved to have a very quick payback for the hospital. Temperature setbacks saved $66,000 per year, and turning off lights saved another $40,000 annually.
Catching a complication
Perhaps the greatest potential use of the dashboard is as a troubleshooting tool and early warning system to identify inconsistencies or changes over time. For example, by using the tool, the facility staff discovered natural gas usage was higher than expected, and it was counterintuitively higher in the summer than in the winter.
To solve a problem with one specific room that was too warm, the building operator had lowered the air handling unit supply temperature and increased the static pressure of the air handling units to increase the cooling airflow and lower the supply air temperature to that room. That resolved the heat issue for that room, but it meant the entire building was being supplied with colder air, with the net result of requiring a considerable amount of reheating for all of the other HVAC zones in the building. The hospital was effectively paying to simultaneously cool and reheat the air while placing unnecessary strain on its equipment—all to satisfy one room.
Traditionally, this might have gone unnoticed, but the dashboard allowed the gas expense spike to become very noticeable. That prompted closer review of how the building systems were being operated and led to identifying the source of the problem and corrective action that saved an estimated $41,000 annually.
The bottom line
The energy dashboard is an economical addition to a facility project that offers a lot of potential to save owners money, especially when it’s incorporated during the design phase. While it’s possible to add an energy dashboard after a building is in operation, this requires the shutdown of utilities in order to add meters. Software for controls and programming is also more easily integrated into a building automation system during original construction.
Another possible application is to display some energy information in a lobby kiosk, where it could serve as an incentive for employees to turn off lights and participate in energy-saving strategies, and as a visible way to demonstrate the hospital’s sustainability commitment to building users.
The University of Kansas Hospital is now planning a new hospital and is pursuing an energy dashboard for that building, too. “The energy dashboard is a vital tool for our implementation and development of energy savings initiatives and strategies,” says Adam Zorn, capital project manager at the hospital. “It serves as both a real-time, daily verification of the system efficiency and as an important part of our predictive maintenance process.”
Richard McKown, PE, FPE, LEED AP, is director of healthcare engineering and principal for Burns & McDonnell. He can be reached at firstname.lastname@example.org.