In the United States, Standard 90.1-2010 serves as a critical legal benchmark: Standard 90.1 - ASHRAE
: Introduced more stringent equipment efficiencies and specific design requirements for hydronics and airside systems. It also mandated variable speed pump control for many chilled water systems. ashrae 90.1-2010
: Updated Lighting Power Density (LPD) allowances and introduced more detailed methods for determining power allowances, such as the Space-by-Space Method. In the United States, Standard 90