Daylighting Sensor Controls Measure

This measure adds daylighting sensor controls to a building’s spaces where they are daylighted by sidelighting and/or toplighting based on NECB-2011.
Some parts of this measure used the existing measure, called “assign_ashrae_9012010_daylighting_controls”, in OpenStudio’s BCL with some modifications.

Description

The workflow of this measure is as follows: 1. Find all spaces in a building that have the fenestration types of “fixed window”, “operable window”, and “skylight” on exterior surfaces. 2. Calculate “Primary Sidelighted Areas” and “Sidelighting Effective Aperture” for the spaces that have fixed and/or operable window(s), as per NECB-2011’s Article 4.2.2.9. and Article 4.2.2.10. See Notes #1 and 2 below. 3. Calculate “Daylighted Area Under Skylights” and “Skylight Effective Aperture” for the spaces that have skylight(s), as per NECB-2011’s Article 4.2.2.5. and 4.2.2.7. See Notes #3 and 4 below. 4. Exclude the daylighted spaces where the NECB-2011’s required conditions are not met for either “Primary Sidelighted Areas”, “Sidelighting Effective Aperture”, “Daylighted Area Under Skylights”, or “Skylight Effective Aperture”. See Note #5 below for the NECB-2011’s required conditions. 5. However, include all daylighted office spaces larger than 25 m<sup>2</sup> even if they do not meet NECB-2011’s required conditions for either “Primary Sidelighted Areas”, “Sidelighting Effective Aperture”, “Daylighted Area Under Skylights”, or “Skylight Effective Aperture”. This approach is based on NECB-2011’s Article 4.2.2.2. 6. Create daylighting sensor(s) (one or two) for the daylighted spaces that should have daylighting sensors controls. See Note #6 below for number of sensors.

Note #1:
Note #2:
Note #3:
Note #4:
Note #5:
Note #6:

Approach

This measure has some assumptions and limitations: 1. It does not consider rooftop monitors regarding toplighting. 2. It does not exclude overlapped daylighted areas regarding wide windows in spaces daylighted by sidelighting. 3. It assumes that skylight(s) are in parallel to roof(s) edges. 4. It assumes that skylight(s) are flush with ceiling(s). 5. It assumes that skylight(s) is(are) rectangular in shape. 6. In the calculation of extension of skylight(s)‘ projection onto the floor, the window head height is subtracted from the associated vertical distance of skylight projection to the exterior wall once (even if the exterior wall has multiple windows). 7. It does not consider space types (see NECB-2011’s 4.2.2.8.) regarding whether they should or should not have daylighting sensor controls. 8. It does not consider this clause from NECB-2011: 4.2.2.4.: “enclosed space > 800 m<sup>2</sup> in buildings located above the 55˚N latitude” regarding toplighting.

Testing Plan

Files Added/Modified