Hot Tip

Pursue this point if your project space has sufficient available daylight to make a lighting control system that includes daylight sensors worthwhile. Have your lighting designer provide estimated annual energy savings and simple payback calculations and, if warranted, a daylight simulation to examine possible control strategies. 

This credit addresses your project’s entire connected lighting load. It’s not limited either to spaces near windows or to daylit spaces. 

You can use the same lighting power calculations you completed for EAp2.

Daylight-sensitive controls work only with ambient space lighting—not task lighting, art illumination, or other forms of lighting.

Spaces with daylight can save more energy in a “manual-on/auto-off mode” by forcing the user to turn on the lights. Many people will prefer to keep the lights off if they have good daylight.

Some new sensors self-adjust and “learn” occupancy patterns in the space. Some systems allow the time-out delay to change depending on the time of day to adapt to changing occupancy patterns. This can save even more energy by providing short time delays at night for cleaning crews, and longer time delays during the day to avoid false “off” occurrences.

ASHRAE 90.1-2007 guidelines require occupancy-sensitive controls for buildings of 5,000 ft2 or greater, but this credit requires the use of occupancy-sensitive controls for all buildings, regardless of size.

The credit requirement is to connect 50% of the project lighting load to daylight sensors. This does not mean connecting to 50% of the total number of fixtures, as some fixtures have higher power loads than others. If 30% of fixtures contribute to 60% of your lighting load, then you need fewer sensors to meet the minimum threshold for the credit. Or conversely, by adding more sensors, you can achieve the 75% Exemplary Performance threshold and earn an extra point through IDc1.

Some spaces are more suitable for daylight sensors than others. For example, offices can function with sufficient daylight and daylight sensors, but storage spaces typically need artificial lighting. 

It generally makes sense to control the fixtures within 15 feet of the windows, but the credit requires that you place the sensors within 15 feet of the windows. Unfortunately, it can be counterproductive to dictate the location of fixtures in this way without looking at the specific site conditions.