The U.S. Department of Energy’s Commercial Buildings Program and DOE’s National Renewable Energy Laboratory are working with the American Society of Heating, Refrigerating, and Air Conditioning Engineers and the buildings industry to find ways to reduce the energy intensity of large hospitals, schools, and retail buildings by 50%.
U.S. hospitals spend more than $5 billion annually on energy, often equaling 1% to 3% of a typical hospital’s operating budget. Hospital energy use is extremely high, and the need for reliability is unprecedented. Hospitals in the U.S. alone use more than 836 trillion BTUs of energy annually and produce more than 2.5 times the carbon dioxide emissions of commercial office buildings
The NREL commercial buildings team of NREL Senior Research Engineer and AEDG Project Chair Shanti Pless, Eric Bonnema, and Matt Leach led the development of the Large Hospital, Retail, and School 50% Savings AEDGs. Pless was chair of the project committees of industry experts, and Bonnema and Leach provided efficiency expertise and energy modeling optimization support.
The 50% AEDG series is a new group of publications that builds on previous successes. Collaborators including DOE and NREL published a series of six 30% AEDGs covering structures ranging from small office buildings to highway lodging to self-storage buildings. Between the 30% and 50% AEDGs, there are roughly 450,000 copies currently in circulation.
The AEDGs are written for owners, design teams, and contractors — the professionals who will be constructing these buildings. If they don’t have experience in energy efficiency, they can look to these guides for examples and details on how to do it themselves. The guides have recommendation tables for all climate zones in the United States.
“Hospitals have strict ventilation requirements, and they bring in a certain amount of fresh air along with a certain amount of re-circulated air,” Bonnema said. “There is a huge potential for savings if you set up your system differently, since most hospitals are using energy to cool the air and then heat it back up.”
Jeff Boldt is the director of engineering for KJWW Engineering Consultants, and he was also a project team member for the Large Hospital AEDG. “It’s really interesting when you look at a large hospital energy model; the biggest use of energy is the reheat. It’s because you have to dehumidify all the air. For instance, you cool it down to 52 degrees in order to dehumidify it. Then, your boiler comes on to reheat the air. That process is usually the single largest use of energy in a hospital. This guide figures out how to get that reheat for free or cause the reheat not to happen at all.”
According to Boldt, the AEDG will help the healthcare industry understand that there are practical ways to design a building that uses 50% less energy. “I like that they are prescriptive because a lot of people aren’t comfortable with energy modeling. With the AEDGs, we’ve done all the energy modeling, and you can hand this to your design team and say ‘I want you to follow the items in this AEDG,’ and your team can go from a checklist and know what they are getting.”