John Mardaljevic PhD FSLLProfessor of Building Daylight Modelling School of Civil & Building Engineering

Loughborough UniversityLoughborough, UK

Urban Microclimate: Daylight/Solar

Overcoming obstacles to high density resilient cities | urban microclimate event City Hall, London, UK 6 January 2017

Light

Power

Heat

Performance measures

Some measure of sunlight availability

And/Or Some measure of skylight availability

Or Climate-based daylight modelling (CBDM)

The Sunlight Beam Index

SBI is an area measure of the ‘connectedness’ of a building aperture to all of the possible occurring sun positions for that locale and for that particular aspect of the aperture including all possible obstructing surfaces - averaged across the aperture.

Units: 1⇥ 1 = 1m2 hrs

1m2 aperture set in thin wall 1m2 aperture set 20cm deep reveal

Aperture Without reveal With reveal (20 cm)

orientation SBI [m

2hrs] SBI [m

2hrs]

North 204 84

NE 608 414

East 1,348 1,037

SE 1,826 1,343

South 1,927 1,340

SW 1,822 1,342

West 1,345 1,033

NW 604 411

Cumulative annual sunlight beam index

London, UK

Stot = 1754 m2 hrs : Aglaz = 1.54 m2 [ Snorm = 1139 hrs ]

1 2 3 4 5 6 7 8 9 10 11 12Month

0

4

8

12

16

20

24

Hour

S [m2 hrs]

0.00

0.10

0.20

0.30

135 SWE-Ostersundmod01/glaz01

135glaz01

Glazing orientation(glaz01)

Sun at ~ normalincidence to glaz01

Sun blockedby local obstructions

NightDay (no incident sun)

Day (possible sun)

Sun at ~ grazing incidenceand/or heavily shaded

glaz05

glaz03

glaz08

glaz04

glaz09a

glaz09b

glaz09c glaz10b glaz10a glaz01

glaz02

glaz06a

glaz06b glaz07a

glaz07b

glaz07c

Stot = 24520 m2 hrs : Aglaz = 25.52 m2 [ Snorm = 961 hrs ]

1 2 3 4 5 6 7 8 9 10 11 12Month

0

4

8

12

16

20

24

Hou

r

S [m2 hrs]

0.00

0.50

1.00

1.50

2.00

2.50

01-02-03-04-05-06a-06b-07a-07b-07c-08-09a-09b-09c-10a-10b mod01-GBR-London-135

Scaleability

The Aperture Skylight Index

ASI is an area measure of the ‘connectedness’ of an aperture to the sky vault in terms of the illumination received from a uniform luminance sky dome - averaged across the aperture.

0 50 100 150Zenith angle

0

500

1000

1500

2000

Nor

mal

ised

lux

✓

✓

NUS

Area wght. 530

Dir sky comp of NUS

Area wght. 530

Int-ref comp of NUS

Area wght. 0

mod01sh0/glaz01glaz01

NUS [lux]

100

1000

530

NUS

Area wght. 467

Dir sky comp of NUS

Area wght. 467

Int-ref comp of NUS

Area wght. 0

mod01shv/glaz01glaz01

NUS [lux]

100

1000

467

NUS

Area wght. 690

Dir sky comp of NUS

Area wght. 690

Int-ref comp of NUS

Area wght. 0

mod01s00/glaz01glaz01

NUS [lux]

100

1000

690

NUS

Area wght. 996

Dir sky comp of NUS

Area wght. 996

Int-ref comp of NUS

Area wght. 0

mod01s99/glaz01glaz01

NUS [lux]

100

1000

1000 Stot = 1698 m2 hrs : Aglaz = 1.00 m2 [ Snorm = 1698 hrs ]

1 2 3 4 5 6 7 8 9 10 11 12Month

0

4

8

12

16

20

24

Hou

r

S [m2 hrs]

0.00

0.05

0.10

0.15

0.20

0.25

045 ITA-Romamod01s99/glaz01

1698

Stot = 1701 m2 hrs : Aglaz = 1.00 m2 [ Snorm = 1701 hrs ]

1 2 3 4 5 6 7 8 9 10 11 12Month

0

4

8

12

16

20

24

Hou

r

S [m2 hrs]

0.00

0.05

0.10

0.15

0.20

0.25

000 ITA-Romamod01s99/glaz01

1701

Stot = 1091 m2 hrs : Aglaz = 1.00 m2 [ Snorm = 1091 hrs ]

1 2 3 4 5 6 7 8 9 10 11 12Month

0

4

8

12

16

20

24

Hou

r

S [m2 hrs]

0.00

0.05

0.10

0.15

0.20

0.25

000 ITA-Romamod01s00/glaz01

1091

Stot = 1222 m2 hrs : Aglaz = 1.00 m2 [ Snorm = 1222 hrs ]

1 2 3 4 5 6 7 8 9 10 11 12Month

0

4

8

12

16

20

24

Hou

r

S [m2 hrs]

0.00

0.05

0.10

0.15

0.20

0.25

045 ITA-Romamod01s00/glaz01

1222

Stot = 897 m2 hrs : Aglaz = 1.00 m2 [ Snorm = 897 hrs ]

1 2 3 4 5 6 7 8 9 10 11 12Month

0

4

8

12

16

20

24

Hou

r

S [m2 hrs]

0.00

0.05

0.10

0.15

0.20

0.25

045 ITA-Romamod01sh0/glaz01

897

Stot = 743 m2 hrs : Aglaz = 1.00 m2 [ Snorm = 743 hrs ]

1 2 3 4 5 6 7 8 9 10 11 12Month

0

4

8

12

16

20

24

Hou

r

S [m2 hrs]

0.00

0.05

0.10

0.15

0.20

0.25

000 ITA-Romamod01sh0/glaz01

743

Stot = 612 m2 hrs : Aglaz = 1.00 m2 [ Snorm = 612 hrs ]

1 2 3 4 5 6 7 8 9 10 11 12Month

0

4

8

12

16

20

24

Hou

r

S [m2 hrs]

0.00

0.05

0.10

0.15

0.20

0.25

000 ITA-Romamod01shv/glaz01

612

Stot = 795 m2 hrs : Aglaz = 1.00 m2 [ Snorm = 795 hrs ]

1 2 3 4 5 6 7 8 9 10 11 12Month

0

4

8

12

16

20

24

Hou

r

S [m2 hrs]

0.00

0.05

0.10

0.15

0.20

0.25

045 ITA-Romamod01shv/glaz01

795

Glazingorientation

Case Apertureskylight index

Sunlightbeam index

Rome, Italy

NUS

Area wght. 293

Dir sky comp of NUS

Area wght. 293

Int-ref comp of NUS

Area wght. 0

mod01s05/glaz01glaz01

NUS [lux]

100

1000

Stot = 795 m2 hrs : Aglaz = 1.00 m2 [ Snorm = 795 hrs ]

1 2 3 4 5 6 7 8 9 10 11 12Month

0

4

8

12

16

20

24

Hou

r

S [m2 hrs]

0.00

0.05

0.10

0.15

0.20

0.25

045 ITA-Romamod01shv/glaz01

1m2 aperture0.2m reveal depth0.5m overhang (top & sides)

1400

1000

600

200

kWh/m2

N

CBDM

05/01/2015 13:42Nordstrom Tower on 57th St. will be world's tallest residence - NY Daily News

Page 1 of 5http://www.nydailynews.com/life-style/real-estate/new-condo-tower-57th-st-world-tallest-article-1.1860838

BY KATHERINE

CLARKE

A A A

Nordstrom Tower in Midtownwill be world's tallestresidential buildingExtell Development's proposed tower will rise to 1,775 feet at 227 W. 57th St., taller thanthe Empire State Building and slightly under 1 World Trade Center.NEW YORK DAILY NEWS / Published: Wednesday, July 9, 2014, 5:21 PM / Updated: Thursday, July 17, 2014, 4:23 PM

SHARE THIS URL

nydn.us/1toFmL4

258 209 20

Start craning the necks — a newMidtown condo tower is slated tobe the tallest residential buildingin the world.

The Nordstrom Tower, at 227 W.57th St., will rise to a whopping1,775 feet at its spire, making itjust a foot shorter than 1 WorldTrade Center, the tallest buildingin the Western Hemisphere.

But the new building willovershadow other supertallresidential structures such as the1,396-foot 432 Park Ave. andthe 1,450-foot World One Towerin Mumbai — both underconstruction.

Architectural drawings of the

New York News Politics Sports Entertainment Opinion

HOMES FOOD HOROSCOPES EDUCATION COMICS GAMES LIVING PICS FASHION PICS BLOGS

Wednesday, July 9, 2014

[when completed in 2018]

The legal agreement for the development includes a

measure of ‘daylight injury’ predicted using CBDM

censored

The Art Students League Building

West 57th Street, New York

Existing Proposed

2005 proposal

Case Predicted TAIL Change in

[klux hrs] TAIL [%]

Existing 36,946

Proposed 0% refl. 23,455 -36.5%

Proposed 50% refl. 29,972 -18.9%

TAIL = Total annual illumination

2013

Mostly architecture — some technology

Mostly technology — some architecture

Relevant papers / links

J. Mardaljevic and N. Roy. The sunlight beam index. Lighting Research and Technology, 48(1):55–69, 2016. Open access PDF

J. Mardaljevic, G. M. Janes, and M. Kwartler. The ‘Nordstrom Tower’: A landmark daylight injury study. CIE 28th Session, Manchester, UK, 2015. Open access PDF

J. Mardaljevic, R. Kelly Waskett, and B. Painter. Neutral daylight illumination with variable transmission glass: Theory and validation. Lighting Research and Technology, 48(3):267–285, 2016. Open access PDF

J. Mardaljevic. Climate-Based Daylight Modelling And Its Discontents. CIBSE Technical Symposium, London, UK, 16-17 April, 2015. Open access PDF

J. Mardaljevic & G. M. Janes. Multi-Scale Daylight Modelling For Urban Environments in (Solar Energy at Urban Scale). John Wiley and Sons, Inc., 2012. Open access PDF

J. Mardaljevic. Aperture Sunlight and Skylight Indices: A Rating System for Windows and Shading Devices. CIBSE Technical Symposium, Loughborough, UK, 5-6 April, 2017. [Submitted]

Urban Solar Micro-Climate Link

Acknowledgements

George Janes: George M. Janes & Associates, New York, USA

Michael Kwartler: Environmental Simulation Center, New York, USA

Electrochromic glass photos courtesy SAGE Electrochromics, Inc.

Residential house model courtesy of the VELUX Corporation

http://climate-based-daylighting.com/

Link to staff webpage