Visual Acuity Evaluations I -Daylight Factor Visualization

from Visible Radiation (Daylight) Studies | Master in Sustainable Design

In this section, we explored the daylight factor in this office to measure the available daylight. Remind that the daylight factor can be calculated using the following function:

Daylight Factor = Ei/Eo x 100%

Daylight Factor is defined as a percentage value of the total daylight available, Ei is the illuminance (lux) on the indoor working plane due to the daylight, and Eo is the simultaneous outdoor illuminance (lux) on a horizontal plane from an unobstructed hemisphere of the overcast sky (“CIE overcast sky,” 10,000 lux). It is essential to note that the daylight factor is calculated when the sky condition is fixed.

A room is considered well lit is when the daylight factor reaches at least 2% and less than 5%, but supportive artificial light may still be required. Lastly, there will be no need for artificial light if the daylight factor is over 5% but might feel vigorously lit.

Baseline Visual Acuity Evaluations II - Point-in-Time Illuminance

This section explored the illuminance on the working plane (desk surface) at specific times and dates, 9:00 a.m. and 3:00 p.m. on March 21st and December 21st. The target range is between 300 lux (Target lux) and 3000 lux (Excessive lux).

Climate-Based Annual Daylighting Evaluations

The following simulations were done for the open office space, with a schedule of 8 am- 6 pm on Monday to Fridays with DST. The simulations were also calculated for the entire year. The metrics measured are spatial daylight autonomy [% of area], annual sunlight exposure [% of area], LEED v4.1 credits earned [#], and mean illuminance [lux]. In order to get these results, a sensor grid was created within the grasshopper script with a grid spacing of 0.3 meters that was offset 0.76 meters away from the floor plane. The target lux for this grid was 300 lux.

Spatial Daylight Autonomy (sDA) Mean Illuminance

Annual Sunlight Exposure (ASE)

Visual Comfort Evaluations I - Annual Glare Analysis

This section explored the possible glare that may adversely affect the occupants in the assigned case buildings. When the DGP (Daylight Glare Probability) falls between 0.35 and 0.40, the occupant can detect the glare, but it will not cause trouble. However, when the DGP is between 0.40 and 0.45, the occupant will feel disturbed by the glare, and they will seek another place for working due to the intolerable glare when DGP is over 0.45.

Perceptible Glare

Disturbing Glare Intolerable Glare

B. Visual Comfort Evaluations II - Point-In-Time Glare Analysis

The point for this analysis has been selected to understand the glare while all the windows are within the camera range. We understand that this requires the camera to be in a corner where there will be imperceptible glare (according to the simulations) but it provides a wholesome analysis by considering the high illuminance surfaces and it can be interpreted that the locations with high illuminance will experience glare during these times.