5 lighting control features now required by ANSI/ASHRAE/IES 90.1-2013

The ANSI/ASHRAE/IES Standard 90.1-2013 Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2013) incorporated more than 120 addenda to the 2010 standard. These changes significantly fine-tuned the design requirements for code-compliant lighting controls systems, mechanical systems and the building envelope.

The five biggest changes to the lighting control requirements are dedicated to saving energy by turning off or reducing lights and plug-load equipment more quickly when unnecessary or not in use. These requirements also added a tabular format to clarify the specific lighting control requirements by space type.

1. Respond sooner to unoccupied spaces. Previous versions of Standard 90.1 allowed lighting in a space to remain on for up to 30 minutes after the last occupant left. The new code trims the amount of time that a lighting system can illuminate an empty space by one-third, requiring that lights be automatically reduced or shut off within 20 minutes after occupants have left. Select occupancy sensors with a 20-minute time delay to satisfy this energy-saving addendum. 
2. Automatically reduce plug loads in more spaces. The growing energy consumption by equipment (computers, printers, etc.) at the receptacle is garnering more attention in the energy code. While Standard 90.1-2010 required automatic receptacle control in private offices, open offices and conference rooms, ensuring that devices did not drawing power in these spaces when unoccupied, Standard 90.1-2013 has expanded the role of automatic receptacle control and now requires rooms that are primarily used for printing and/or copying, breakrooms, classrooms (other than computer classrooms) and individual workstations to be outfitted for receptacle control as well. There are two additional changes to the receptacle control requirements that are important to note. Occupancy-based turn-off is required within 20 minutes of a space becoming unoccupied, instead of the 30 minutes allowed by Standard 90.1-2010. In addition, controlled receptacles must be visually marked to allow users to differentiate between controlled receptacles and those that are not. 
3. Automatic daylighting control now required in secondary areas. Automatic daylight-responsive controls are now required deeper into the floorplate. Daylighting controls must be in secondary sidelighted areas where the combined controlled power in the primary and secondary daylighted areas is above 300 watts (W). Although the combined wattage of primary and secondary sidelighted areas is considered in determining where control is necessary, the code requires that the primary and secondary areas be controlled separately.
4. Automatic partial-off in more spaces. There are many areas in a building that are often unoccupied, yet these might not be good candidates for an automatic off lighting control strategy due to safety concerns or the general needs and use of the space. Standard 90.1-2010 recognized this type of space and reduced its energy use by requiring that lights be automatically turned partially off within 30 minutes of the space becoming unoccupied. The partially off functionality was further defined as light levels being reduced by at least 50 percent. Standard 90.1-2013 requires that more spaces be equipped to turn partially off and mandates this functionality in stairwells, corridors, classroom laboratories, some lobbies, small storage areas, library stacks and warehouses. The requisite time delay has also been reduced to 20 minutes, instead of 30. 
5. New tabular format. Standard 90.1-2013 now includes a table that summarizes the minimum lighting control requirements by space type. The goal was to make the lighting control requirements in Standard 90.1-2013 clearer and easier to understand in the hopes that it would improve compliance and be easier to enforce. 

Standard 90.1-2013 now includes a table that summarizes the minimum lighting control requirements by space type.

Note: for project-specific requirements and interpretation of the changes to lighting and lighting controls requirements within the energy code, please directly consult Standard 90.1-2013 and the building authority having jurisdiction.

Learn more about Standard 90.1-2013.