What Factors Affect Building Energy Use?
Buildings can be used for a variety of functions: administrative offices, faculty offices, classrooms, laboratories for research and classes, food services, conference rooms, study areas and on and on.
We’ve grouped these uses into five categories that we call classrooms, laboratories, housing, community, and offices. Each building type has a unique energy profile.
For example, laboratory spaces use a lot of energy because they require much higher ventilation rates, as the air cannot be recirculated in a lab. The air coming into a lab must be 100% outside air (not recirculated), and then it must completely leave the building through the exhaust systems. Moving this quantity of air with fans, and heating and cooling the air, is an energy intensive process.
Check out all of the different building types on the Campus Energy Education Dashboard (CEED).
No matter what type of building you look at, you'll see that chilled water is highest when it’s warmer outside, and that steam is highest when it's colder outside. This is because more steam is required to heat the buildings during the colder months of the year. Inversely, during the summer, you'll see chilled water reach its peak usage because the buildings need that precious cooling power.
Steam is highest when it’s colder outside.
319,189 kBtu > 36,225 kBtu
Chilled Water is highest when it's warmer outside.
56,225 kBtu < 458,907 kBtu
The number of building occupants has the largest impact on the lighting and plug loads of a building.
People also affect the Heating, Ventilation, and Air Conditioning (HVAC) system based on when the system is scheduled to be on and off. For example, the HVAC schedule needs to be properly tuned to the hours when the building is occupied. If it’s not, there is potential energy being wasted and/or uncomfortable people in the building.
In the graph to the left you can see how the energy demand rises over time with the classroom's occupancy in Giedt Hall.