Abstract

Opening in 2007, Dell Children’s Medical Center in Texas, USA, became the world’s first LEED Platinum hospital in 2009, establishing it as a milestone in sustainable healthcare. In 2011, a new 75,000-bed tower for the existing Dell Children’s Hospital was also commissioned.

Objectives
The vision was to achieve LEED Platinum status and carry the legacy of the base project through multiple future phased expansion. The challenge was to develop innovative methods to achieve mechanical and electrical efficiencies of greater than 20% in the new bed tower. These systems also had to meet the owner’s financial requirements of a 12% rate of return on investment or six-year payback.

Methodology and results
Features included renewable solar power and heating water systems, an integrated lighting and HVAC controls solution, and air-side energy recovery to achieve savings above the baseline requirements of LEED.

A review of the Phase I combined heat and power plant was conducted to determine plant efficiency. The results of the study and the systems innovated for the new bed tower led to combined energy savings that were 46% more efficient than the baseline building.

The renewable solar power and heating water system, an integrated lighting and HVAC controls solution, and air-side energy recovery have reduced the bed tower’s environmental impact. The solar system backfeeds the normal power system and collects 35815 kWh AC annually.

Solar heating hot water systems maximise the roof area of the new bed tower and reduce the amount of natural gas used for heating loads. The heating-water return water was run through a closed solar array of 50 panels collecting 302,340,596 BTU/h annually.

Dell Children’s Medical Center of Central Texas is part of Austin city’s sustainability initiative. The project received a five-star rating from the Austin Energy Green Building Rating System; it is currently the only five-star rated commercial building in the programme.

Conclusions
Ongoing verification: Overall, the building is operating within a typical range of tolerance of about 8.2%. The facility is refining its controls strategies to narrow the gap between the model and actual data. Lifecycle cost analysis: This was used in all major system decisions. The need for a 12% rate of return or six-year payback was met.