A recent energy study at Legacy Salmon Creek Medical Center in Vancouver, WA is expected to have an impact on the future of hospital design. The study, which took place over one month in Winter 2011, confirmed that in many hospitals heating systems use the most energy.
Study partners were the University of Washington’s (UW) Integrated Design Lab and Eugene, OR-based SOLARC Architecture & Engineering Inc. The UW project team worked with Legacy Health officials to monitor energy use at the hospital during the one month study period.
The study is available online. It was made possible with funding from the U.S. Department of Energy (DOE), through the American Recovery and Reinvestment Act, and the Northwest Energy Efficiency Alliance’s BetterBricks Initiative.
“This kind of detailed data is simply not available to experts in hospital design, construction, and operations nationally; it is much needed and anticipated by those seeking to develop high performance hospitals,” said Heather Burpee, research assistant professor with the UW Integrated Design Lab.
Legacy Salmon Creek Already Efficient
Legacy Salmon Creek, which opened in August 2005, was chosen because it already performs more efficiently than the typical U.S. hospital in terms of its use of electricity and natural gas. The national and state average Energy Use Index for hospitals is about 270 KBtu/sf-yr, while Salmon Creek’s EUI is 215 KBtu/sf-yr.
“We could have chosen any hospital in the nation for this study, and Salmon Creek was the best choice,” said Michael Hatten, principal of SOLARC. “They have a reputation for efficient energy use, and they were enthusiastic to work with us.”
“We designed and built this hospital with energy efficiency and high performance in mind, and we have since developed a strong strategic energy management plan in partnership with BetterBricks,” said Pat Lydon, coordinator of strategic resources for Legacy Health. “This study is a great opportunity to share our successes with a larger audience that has similar goals in mind.”
The BetterBricks Initiative encourages hospitals to engage in strategic energy management the way that Legacy Salmon Creek has. Activities such as hiring a resource conservation manager, benchmarking energy use, tuning up existing systems and equipment, training building operators and facility staff, and enhancing ongoing operations and maintenance practices all contribute to significant energy savings in hospitals.
National societies such as ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers), along with key engineering firms and the U.S. DOE, are among those who will be able to use this data to make more informed decisions when working with design teams and hospital owners for both new construction and retrofitting.
According to Energy Star, U.S. healthcare organizations spend more than $6.5 billion annually on energy costs, and that figure is rising. Based on their calculations, every $1 a nonprofit hospital saves on energy is the equivalent to $20 in new revenue.
The energy study dismantled some long held beliefs. Imaging equipment—notably MRI machines—are often thought to be large energy users. But study results indicate all imaging equipment accounts for less than 1% of energy use. Likewise, hot water is another relatively small energy user in the hospital, at less than 2% of total energy use. This information will help designers and energy experts to focus on larger energy users, rather than devoting time and dollars to areas that would result in very small relative gains.
So where can energy savings be found? The study found air reheating equipment to be the largest single energy user by far, accounting for more than 40% of energy use. In a reheating system, air is cooled to a common low temperature, and then reheated to provide comfortable air temperatures. A common practice, it also is very energy intensive.
According to the findings, there are limited, but promising, opportunities for reducing reheating in hospitals. The UW’s Integrated Design Lab has found that most hospitals generate all the heat they need on any day that the temperature is above 20 degrees; the challenge is moving that heat to the right places. (“Targeting 100!”, a separate report by IDL, describes ways hospitals could use significantly less energy without spending significantly more money.)
(Chart: University of Washington, Integrated Design Lab)