Little by little, a little becomes a lot. How much overdue maintenance becomes a lot of energy expense?
Aiming to answer that question is a paper entitled “Deferred Maintenance: The Cost of Doing Nothing” at DOE’s Better Buildings Solutions website. The base case for the analysis is a five-story, 115,000-square-foot building that houses the mathematics and statistics departments at North Carolina State University. Constructed in 2009, the facility includes general classrooms, faculty offices and lecture halls. Assuming that building systems are well maintained, the facility’s annual energy costs total $164,200, which consists of HVAC (54%), equipment (26%) and lighting (20%).
The researchers then examined the drag of deferred maintenance items on energy costs – lighting controls, filters, fans, pumps, cooling tower, chillers, boilers, thermostats, humidity control, night setback, outside air ventilation and economizer cycle. A sampling of miscarried maintenance and the impact on energy consumption includes the following:
Other factors in the analysis are inefficient humidity and temperature setpoints and setbacks as well as ventilation malfunctions (economizers, outside air and CO2 sensors). All in all, the maintainable mechanical and electrical systems account for 75% of building energy.
The researchers create a worst case scenario in which all of the maintainable items fail.
The cost? An 81% increase in annual energy, from $164,000 to $297,852.
That’s a lot of little by little.