OVERVIEW




Energy Outcomes

Based on a highly integrated bundle of schematic architectural, building mechanical, and plant system designs, Targeting 100! is able to achieve a 60% reduction in energy use compared to average operational hospitals, thus meeting the 2030 Challenge goal for 2010-2015. Targeting 100! also achieves the goal of reducing energy to 100 KBtu/SF Year across all six study cities. The major energy end use reduction was in heating energy, specifically re-heat energy. This was expected, as heating energy was identified as the single largest energy load, and therefore the best target of opportunity for energy savings. The key moves to decreasing the heating load and overall energy footprint were 1) first reducing loads on the envelope through solar control; 2) de-coupling of space tempering and ventilation for most spaces using supplemental radiant sources for heating and cooling rather than fully relying on air-transport for tempering during peak conditions; 3) using displacement ventilation with 100% Outside Air to deliver required air changes in most spaces; 4) turning down air changes in highly regulated areas while un-occupied; and 5) using efficient, right sized central plant approaches with maximum heat recovery.

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This de-coupled and de-centralized scheme of heating, cooling and ventilating systems acting in close coordination with solar heat gain load reductions, heat recovery from significant powered or heated energy sources, and a large ground source heat pump system (or distributed heating system, or heat recovery chiller) significantly reduces the energy demands for ventilation, space heating, cooling and water heating.

Surprisingly similar energy results were seen between the two architectural schemes in the study. While maintaining a 30 percent window-to-wall ratio for both architectural schemes, the more articulated version has nearly double the actual window area due to its overall increase in surface area. Despite this increase in surface area, this scheme does not require significantly more energy. Hospitals are typically internally load dominated, meaning that the systems used to heat, cool, and ventilate the building are a large source of the overall load. The high performance options in both architectural schemes significantly reduce those internal and envelope loads. In summary, it is possible to build a hospital with significantly more surface area and still meet aggressive energy targets such as the 2030 Challenge.