U.S. Department of Energy - Energy Efficiency and Renewable Energy
Building Technologies Office
Hospital Energy Alliance: HVAC—Providence Portland Medical Center Video (Text Version)
Below is a text version of the Hospital Energy Alliance video showing the approach to Heating, Ventilation, and Air Conditioning (HVAC) at the Providence Portland Medical Center in Portland, Oregon.
Heating, ventilation, and air conditioning (HVAC) is especially critical in hospitals where patients and their families must be kept in a comfortable environment 24-7; some spaces must be kept at lower temperatures or higher pressures; and air must be filtered for infection control and exchanged at a higher rate than in other commercial buildings. As a result, HVAC is the highest portion of a hospital's energy expenditure, and an area of intense scrutiny for hospitals seeking to lower costs. Providence Portland Medical Center in Portland, Oregon has recently completed major upgrades to its central plant that have resulted in significant energy savings.
We originally started about eight years ago putting this plant together and we had about 13,000 tons of cooling power at the time; three small chillers. We moved this up. We've got three 1,200-ton chillers here now. We incorporated energy savings in heat exchangers and plate exchangers.
Everything about the chilled-water system has variability built into it. The chillers themselves; the pumps are on variable-speed drives.
If set up properly, you aren't just running the motor at 100 percent. Two of our chillers are on a VFD so you can run the motor at a slower rate. On a day like today, it's about 52, 55 degrees outside. We're putting out about 150 tons of cooling to the hospital right now. The MRI area with the equipment rooms needs to be kept about 67, and a couple other areas in the hospital need to be kept at a low temperature and we're able to accomplish that by using outside air coming into the main hospital for keeping the building cool, and then also that little bit of chilled water that's needed for those other areas. If we didn't have that heat exchanger, we'd be running a chiller just wasting energy.
New 900-horsepower boilers can be dialed down for use on the hottest summer days, which offers extra energy efficiency.
After we built this plant, our incremental cost was about 1.2 million dollars. We had a number of energy-efficiency grants. We had Oregon Business Energy Tax Credits that helped defray that cost and we were able to return our investment dollars in less than two years. This is the most efficient central plant that we have. It's operating today at approximately 205,000 KBTUs per square foot. The national average is more in the 360,000 KBTU per square foot range, so this is a very, very energy-efficient facility.