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LEED v4.1
Data Centers – NC
Indoor Environmental Quality
Daylight

LEED CREDIT

Data-Centers-NC-v4.1 EQc7: Daylight 1-3 points

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SPECIAL REPORT

LEEDuser expert

TODD REED

PA DMVA
Energy Program Specialist

SPECIAL REPORT

LEEDuser’s viewpoint

Explore this LEED credit

Post your questions on this credit in the forum, and click on the credit language tab to review to the LEED requirements.

Credit language

USGBC logo

© Copyright U.S. Green Building Council, Inc. All rights reserved.

Intent

To connect building occupants with the outdoors, reinforce circadian rhythms, and reduce the use of electrical lighting by introducing daylight into the space.

Requirements

Provide manual or automatic (with manual override) glare-control devices for all regularly occupied spaces.

AND

Select one of the following three options.

Option 1. Simulation: Spatial Daylight Autonomy and Annual Sunlight Exposure (1–3 points, 1-2 points Healthcare)

Perform annual computer simulations for spatial daylight autonomy300/50% (sDA300/50%), and annual sunlight exposure1000,250 (ASE1000,250 ) as defined in IES LM-83-12 for each regularly occupied space. Healthcare projects must use each regularly occupied space located in the perimeter area determined under EQ Credit Quality Views. Additionally, calculate the average sDA300/50% value for the total regularly occupied floor area.

For any regularly occupied spaces with ASE1000,250 greater than 10%, identify how the space is designed to address glare.

Points are awarded according to Table 1.

Table 1. Points for Option 1


New Construction, Core and Shell, Schools, Retail, Data
Centers, Warehouses and Distribution Centers,
Hospitality
Healthcare
The average sDA300/50% value for the regularly
occupied floor area is at least 40%
1 point 1 point
The average sDA300/50% value for the regularly
occupied floor area is at least 55%
2 points 2 points
The average sDA300/50% value for the regularly
occupied floor area is at least 75%
3 points Exemplary performance
Each regularly occupied space achieves sDA300/50% value of at least 55% Exemplary performance

or 1 additional point if only 1 or 2 points achieved
above.

Exemplary performance

or 1 additional point if only 1 point achieved above.

The sDA and ASE calculation grids should be no more than 2 feet (600 millimeters) square and laid out across the regularly occupied area at a work plane height of 30 inches (76 millimeters) above finished floor (unless otherwise defined). Use an hourly time-step analysis based on typical meteorological year data, or an equivalent, for the nearest available weather station. Include any permanent interior obstructions. Moveable furniture and partitions may be excluded.

OR

Option 2. Simulation: Illuminance Calculations (1–3 points, 1-2 points Healthcare)

Perform computer simulations for illuminance at 9 a.m. and 3 p.m. on a clear-sky day at the equinox for each regularly occupied space. Healthcare projects should use the regularly occupied spaces located in the perimeter area determined under EQ Credit Quality Views.

Demonstrate illuminance levels are between 300 lux and 3,000 lux at both 9 a.m. and 3 p.m. Spaces with view-preserving automatic (with manual override) glare-control devices may demonstrate compliance for only the minimum 300 lux illuminance level.

Points are awarded according to Table 2.

Table 2. Points for Option 2


New Construction, Core and Shell, Schools, Retail, Data
Centers, Warehouses and Distribution Centers,
Hospitality
Healthcare
Percentage of regularly occupied floor area Points
Percentage of regularly occupied floor area within
perimeter area
Points
55% 1 55% 1
75% 2 75% 2
90% 3 90% Exemplary performance

Calculate illuminance intensity for sun (direct component) and sky (diffuse component) for clear-sky conditions as follows:

  • Use typical meteorological year data, or an equivalent, for the nearest available weather station.
  • Select one day within 15 days of September 21 and one day within 15 days of March 21 that represent the clearest sky condition.
  • Use the average of the hourly value for the two selected days.

Exclude blinds or shades from the model. Include any permanent interior obstructions. Moveable furniture and partitions may be excluded.

OR

Option 3. Measurement (1-3 points, 1-2 points Healthcare)

Measure illuminance in each regularly occupied space. Healthcare projects should use the regularly occupied spaces located in the perimeter area determined under EQ Credit Quality Views.

Achieve illuminance levels between 300 lux and 3,000 lux. Spaces with view-preserving automatic (with manual override) glare-control devices may demonstrate compliance for only the minimum 300 lux illuminance level.

Points are awarded according to Table 3.

Table 3. Points for Option 3


New Construction, Core and Schools, Schools, Retail,
Data Centers, Warehouses and Distribution Centers,
Hospitality

Healthcare
Percentage of regularly occupied floor area
Points

Percentage of regularly occupied floor area within
perimeter area

55% at one time in the year 1 55% at one time in the year 1
75% at two times in the year 2 75% at two times in the year 2
90% at two times in the year 3 90% at two times in the year exemplary performance

With furniture, fixtures, and equipment in place, measure illuminance levels as follows:

  • Measure at appropriate work plane height during any hour between 9 a.m. and 3 p.m.
  • If pursuing one point, take one measurement in any regularly occupied month. If pursuing two points, take two measurements: one measurement in any regularly occupied month, and take a second as indicated in Table 4.
  • For spaces larger than 150 square feet (14 square meters), take measurements on a maximum 10 foot (3 meter) square grid.
  • For spaces 150 square feet (14 square meters) or smaller, take measurements on a maximum 3 foot (900 millimeters) square grid.
Table 4. Timing of measurements for illuminance


If first measurement is taken in …
take second measurement in …
January May-September
February June-October
March June-July, November-December
April August-December
May September-January
June October-February
July November-March
August December-April
September December-January, May-June
October February-June
November March-July
December April-August
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LEEDuser expert

TODD REED

PA DMVA
Energy Program Specialist

USGBC logo

© Copyright U.S. Green Building Council, Inc. All rights reserved.

Intent

To connect building occupants with the outdoors, reinforce circadian rhythms, and reduce the use of electrical lighting by introducing daylight into the space.

Requirements

Provide manual or automatic (with manual override) glare-control devices for all regularly occupied spaces.

AND

Select one of the following three options.

Option 1. Simulation: Spatial Daylight Autonomy and Annual Sunlight Exposure (1–3 points, 1-2 points Healthcare)

Perform annual computer simulations for spatial daylight autonomy300/50% (sDA300/50%), and annual sunlight exposure1000,250 (ASE1000,250 ) as defined in IES LM-83-12 for each regularly occupied space. Healthcare projects must use each regularly occupied space located in the perimeter area determined under EQ Credit Quality Views. Additionally, calculate the average sDA300/50% value for the total regularly occupied floor area.

For any regularly occupied spaces with ASE1000,250 greater than 10%, identify how the space is designed to address glare.

Points are awarded according to Table 1.

Table 1. Points for Option 1


New Construction, Core and Shell, Schools, Retail, Data
Centers, Warehouses and Distribution Centers,
Hospitality
Healthcare
The average sDA300/50% value for the regularly
occupied floor area is at least 40%
1 point 1 point
The average sDA300/50% value for the regularly
occupied floor area is at least 55%
2 points 2 points
The average sDA300/50% value for the regularly
occupied floor area is at least 75%
3 points Exemplary performance
Each regularly occupied space achieves sDA300/50% value of at least 55% Exemplary performance

or 1 additional point if only 1 or 2 points achieved
above.

Exemplary performance

or 1 additional point if only 1 point achieved above.

The sDA and ASE calculation grids should be no more than 2 feet (600 millimeters) square and laid out across the regularly occupied area at a work plane height of 30 inches (76 millimeters) above finished floor (unless otherwise defined). Use an hourly time-step analysis based on typical meteorological year data, or an equivalent, for the nearest available weather station. Include any permanent interior obstructions. Moveable furniture and partitions may be excluded.

OR

Option 2. Simulation: Illuminance Calculations (1–3 points, 1-2 points Healthcare)

Perform computer simulations for illuminance at 9 a.m. and 3 p.m. on a clear-sky day at the equinox for each regularly occupied space. Healthcare projects should use the regularly occupied spaces located in the perimeter area determined under EQ Credit Quality Views.

Demonstrate illuminance levels are between 300 lux and 3,000 lux at both 9 a.m. and 3 p.m. Spaces with view-preserving automatic (with manual override) glare-control devices may demonstrate compliance for only the minimum 300 lux illuminance level.

Points are awarded according to Table 2.

Table 2. Points for Option 2


New Construction, Core and Shell, Schools, Retail, Data
Centers, Warehouses and Distribution Centers,
Hospitality
Healthcare
Percentage of regularly occupied floor area Points
Percentage of regularly occupied floor area within
perimeter area
Points
55% 1 55% 1
75% 2 75% 2
90% 3 90% Exemplary performance

Calculate illuminance intensity for sun (direct component) and sky (diffuse component) for clear-sky conditions as follows:

  • Use typical meteorological year data, or an equivalent, for the nearest available weather station.
  • Select one day within 15 days of September 21 and one day within 15 days of March 21 that represent the clearest sky condition.
  • Use the average of the hourly value for the two selected days.

Exclude blinds or shades from the model. Include any permanent interior obstructions. Moveable furniture and partitions may be excluded.

OR

Option 3. Measurement (1-3 points, 1-2 points Healthcare)

Measure illuminance in each regularly occupied space. Healthcare projects should use the regularly occupied spaces located in the perimeter area determined under EQ Credit Quality Views.

Achieve illuminance levels between 300 lux and 3,000 lux. Spaces with view-preserving automatic (with manual override) glare-control devices may demonstrate compliance for only the minimum 300 lux illuminance level.

Points are awarded according to Table 3.

Table 3. Points for Option 3


New Construction, Core and Schools, Schools, Retail,
Data Centers, Warehouses and Distribution Centers,
Hospitality

Healthcare
Percentage of regularly occupied floor area
Points

Percentage of regularly occupied floor area within
perimeter area

55% at one time in the year 1 55% at one time in the year 1
75% at two times in the year 2 75% at two times in the year 2
90% at two times in the year 3 90% at two times in the year exemplary performance

With furniture, fixtures, and equipment in place, measure illuminance levels as follows:

  • Measure at appropriate work plane height during any hour between 9 a.m. and 3 p.m.
  • If pursuing one point, take one measurement in any regularly occupied month. If pursuing two points, take two measurements: one measurement in any regularly occupied month, and take a second as indicated in Table 4.
  • For spaces larger than 150 square feet (14 square meters), take measurements on a maximum 10 foot (3 meter) square grid.
  • For spaces 150 square feet (14 square meters) or smaller, take measurements on a maximum 3 foot (900 millimeters) square grid.
Table 4. Timing of measurements for illuminance


If first measurement is taken in …
take second measurement in …
January May-September
February June-October
March June-July, November-December
April August-December
May September-January
June October-February
July November-March
August December-April
September December-January, May-June
October February-June
November March-July
December April-August

LEEDuser expert

TODD REED

PA DMVA
Energy Program Specialist

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