Radiance: sDA, ASE LEED V4

[AbhishekSKhanna]

I had posted this 2 days back but was not approved yet. Please help me with this as I am a student and I am nearing my deadline for submission. You quick reply will be highly appreciated.

Location: Minneapolis
Building: 4 Floors, 160 ft X 60 ft X 13 ft one room per floor
Windows to wall area ratio: N 65.4% S 65.4% E 23.1% W 23.1% Glazing U-Value 0.32, SHGC 0.4 VT 0.42 Transmittance 0.458
Test: LEED V4 Daylihgt Option 1: Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE)
Testing only 4th floor
Workplane: 2.79 (0.85 m) above floor
Sensor location: on the workplane (2.79) facing upwards
Process: Dynamic Simulation within Radiance
Reflectance: 20% for floor, 0.4 for walls and ceiling

Procedure followed: Ran dynamic simulation within Radiance for Full year 365 days, Room_4.wpd file indicates 4460 simulations. Run time 4 hours

Questions:
1. Is this approach correct ?
2. The sensor location at 2.79 ft from floor facing upwards is correct of should it be on the ceiling ? In my opinion it must be at the workplane to be analyzed.
2. Is this processing time reasonable for just a single room ? Is there any process to boost speed ?
3. Is there any alternate way to do it like doing it in FlucsDL or anything else ?

Result related questions:
A) ASE: 1000 lux 250 hours (8:00-18:00) -----> Pass 0 of 3360 = 0.00%

1) Process Annual WP data dialog box indicates ASE as Percentage of sensors that achieve the target Lux for the target number of hours.
There is only one sensor at the center of room(x, y) and z =2.79 ft and the probability of getting exposure to direct sunlight is less. How does this sensor percentage based ASE number co-relates to the LEED requirement of 1000 Lux for 250 hours and same area of sDA 300 lux for 50% hours ?

2)According to this, the result set suggests that there is no instance when any portion of floor is exposed to direct sunlight; however, this looks unjustified as considering the North and south windows of 65%. Is my interpretation correct ? Let me know what it indicates.

2) What is the floor area / area percentage associated with this ?

3) What does the number 3360 indicate ?

4) To qualify for LEED credit, ASE must be less than 10%.

5) The sensor location in sensor settings, it is 80, 30, 41.790 but the result summary (DDS File) indicated the WP height as 12.74 (11.89) grid 0.61. I had already set the WP at 2.79 ft as Indicated earlier.
Am I getting the ASE zero because the wp is high up at 12.74 ? I am not sure if or how it has changed (as per DDS file)
Is this height in meters from Z=0 of ground floor ? Is this number in meters ?

6) Is the any way to override this? What should be the sensor location for ASE study ?


B) sDA: 300 Lux 50% hours (8:00-18:00) -----> Pass 2754 of 3360 = 81.96%

1) This percentage is based on the number of hours how does this co-relates with the floor area ?

2) This SDA value appears to be too high for Minneapolis.

3) Where can we find the floor area information associated with sDA ?

4) Full annual hours from 8:00 to 18:00 are 3650 hours so from where the 3360 value come from ?


Is there any document explaining the result for ASE .... ? or regarding its interpretation as per the Result ?

Your quick guidance is highly appreciated.

Thanks,
Abhishek

[jm2000]

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