Wisconsin health care campus achieves water conservation

The University of Wisconsin Hospital & Clinics incorporates a number of water sustainability measures.

By Willa Kuh and Fred Betz, PhD, LEED AP BD+C, Affiliated Engineers Inc., Madison July 17, 2014

The University of Wisconsin Hospital & Clinics (UWHC) will soon open UW Health at The American Center. Referred to as a health care campus, the 42-acre site includes a 492,000-sq-ft hospital, a universal care center, and a wellness campus, representing a unique approach for the Madison, Wis.-based health care provider to serve a growing patient population and establish a service point separate from the main UWHC campus. 

The three-wing facility is designed to be U.S. Green Building Council LEED for Healthcare Silver and to promote the city’s goal of reducing water use. From a base design that would have used 17.6 million gal/year, the selection and right-sizing of mechanical systems and facility equipment reduced the total water demand to 11.7 million gal/year. Of that number, more than half of the building’s water use (6.1 million gal/year) will be with second-generation (reuse) water. 

This water reuse enabled the project’s stormwater management ponds to be designed to a reduced water infiltration level, supporting site design objectives and making it easier to secure approvals for the stormwater management plan. When the building opens in 2015, UWHC will avoid purchasing 12 million gal/year of potable water that the base design would have used. 

“We practice our mission of advancing health both within our facilities and in the communities we serve,” said Ralph Turner, UWHC vice president of facilities and support services. “The water-conserving design of UW Health at the American Center illustrates this, partnering with our host city to meet the water needs of our growing community without increasing groundwater withdrawal.”

The facility incorporates a number of sustainability measures, including the following design elements that work to reduce building energy demand and water use: 

  • Heat recovery chillers for base load heating and cooling
  • High-performance window glazing and roof 
  • High-performance chiller plant with optimized chilled water plant, and six cycles of concentration
  • High-performance boiler plant with stack economizers
  • Efficient lighting, daylight harvesting, and lighting controls
  • Comprehensive HVAC controls to setback unoccupied airflows in operating rooms, imaging, and outpatient spaces
  • Chilled water cooled imaging equipment
  • High-performance central kitchen with variable air volume (VAV) hoods, end-skirts, efficient appliances, water-cooled freezers, and efficient hood layout.
  • Design elements that reduce water use and, consequently, reduce building energy demand, with a premium placed on reducing potable water use include: 
  • Chilled water cooled sterilizers (207 gal of quench water avoided per cycle, 15 gal evaporated in cooling tower per cycle) 
  • A system of interconnected ponds that receive and naturally filter water from air handling units, roofs, lawn, and parking areas 
  • A cooling tower and landscape system that use water from the site’s interconnected ponds
  • Landscape design with minimal irrigation needs
  • An isopropyl alcohol liquid pool cover to reduce pool evaporation by 40% and reduce dehumidification and makeup water heating
  • Efficient water fixtures and devices.

In addition to the direct energy and water savings from these systems, reducing cooling loads on the main chillers reduces heat rejection and consequently evaporated water, drift, and blowdown. Reducing heating loads on the steam boilers reduces blowdown. For nearly every energy savings, there is a complementary water savings, and vice versa. 

Even with relatively low water and sewer rates, the design of this building was able to offer the building’s owner a payback of less than three years for many of the water use reduction-and-reuse elements of the building design. 

Willa Kuh is Affiliated Engineers’ director of planning. She has expertise in campus projects with an emphasis on resource planning, assisting clients in their development of facility master plans, strategic energy plans, sustainability plans, and climate mitigation plans. Kuh is a planner for the UW Health at the American Center project. Fred Betz is a senior sustainable systems analyst with Affiliated Engineers. With a doctorate in building performance and diagnostics from Carnegie Mellon University, he specializes in advanced building systems integration, energy and other resource simulation and planning, renewable energy and power generation, and controls and diagnostics. He is the lead energy and water analyst for the UW Health at the American Center project.