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.
Consider various strategies for harvesting available daylight—like adding light-shelves, reflective surfaces and light-colored finishes. Keep partitions low, especially those parallel to the windows. Alternatively, provide clear or frosted glazing in higher partitions to provide acoustic benefit while still allowing for daylight penetration.
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.
“Closed loop” daylighting controls only control one set of fixtures. With “open loop” controls, multiple zones can be controlled from one sensor and each zone can be calibrated independently to the daylight available in that zone.
