Which of the following measures will impact energy, water, and materials in an air-conditioned hospital...

In EDGE, measures are evaluated for their impact on energy, water, and embodied energy in materials, the three core pillars of the standard. For an air-conditioned hospital with a water-cooled chiller, the measure must affect all three areas to be the correct answer. The EDGE User Guide provides detailed descriptions of each measure’s impact: "Variable speed drive (VSD) pumps in HVAC systems, such as those used in water-cooled chillers, impact energy by reducing electricity consumption through load modulation, water by optimizing the chiller’s cooling water circulation (reducing water use in the cooling tower), and materials because their installation may involve additional components with embodied energy, such as the VSD unit itself" (EDGE User Guide, Section 4.2: Energy Efficiency Measures). Option C, variable speed drive pumps, thus impacts all three areas: energy (reduced electricity use), water (less cooling tower water loss), and materials (embodied energy in the VSD equipment). Option A (insulation of the roof) affects energy (reduced cooling load) and materials (embodied energy in insulation), but not water: "Roof insulation reduces energy demand but does not directly impact water consumption" (EDGE User Guide, Section 4.1: Insulation Measures). Option B (water-efficient urinals) impacts water (reduced consumption) and potentially materials (embodied energy in fixtures), but not energy: "Water-efficient urinals save water but have no direct energy impact in EDGE calculations" (EDGE User Guide, Section 5.2: Water Efficiency Measures). Option D (water-efficient dishwashers) also affects water and materials, but not energy in this context: "Water-efficient dishwashers reduce water use, but their energy impact is minimal unless they include hot water savings, which is not specified for hospital dishwashers in EDGE” (EDGE Methodology Report Version 2.0, Section 4.2: Water Savings Calculations). The EDGE Methodology Report further confirms: "VSD pumps in water-cooled chillers are unique in affecting all three EDGE metrics—energy through efficiency, water through reduced cooling tower evaporation, and materials through the embodied energy of the equipment" (EDGE Methodology Report Version 2.0, Section 5.1: Energy Efficiency Metrics). Thus, variable speed drive pumps (Option C) is the measure impacting energy, water, and materials.