New provisions for commercial refrigeration equipment and improved controls for heat rejection and boiler equipment.Revised equipment efficiencies for heat pumps, packaged terminal air conditioners (PTACs), single package vertical heat pumps and air conditioners (SPVHP and SPVAC), and evaporative condensers.Improvements to daylighting controls, space-by-space lighting power density limits, and thresholds for toplighting.Revised, stricter opaque element and fenestration requirements at a reasonable level of cost-effectiveness.This 2013 edition has been expanded to include new features and more detailed requirements, as well as incorporating changes from more than 100 addenda. It is an indispensable reference for engineers and other professionals involved in design of buildings and building systems. It offers, in detail, the minimum energy-efficient requirements for design and construction of new buildings and their systems, new portions of buildings and their systems, and new systems and equipment in existing buildings, as well as criteria for determining compliance with these requirements.

This standard provides the minimum requirements for energy-efficient design of most buildings, except low-rise residential buildings. Standard 90.1 has been a benchmark for commercial building energy codes in the United States and a key basis for codes and standards around the world for more than 35 years.