ISO 10916:2014

Calculation of the impact of daylight utilization on the net and final energy demand for lighting

ISO 10916:2014 defines the calculation methodology for determining the monthly and annual amount of usable daylight penetrating non-residential buildings through vertical facades and rooflights and the impact thereof on the energy demand for electric lighting. It can be used for existing buildings and the design of new and renovated buildings. ISO 10916:2014 provides the overall lighting energy balance equation relating the installed power density of the electric lighting system with daylight supply and lighting controls (proof calculation method). The determination of the installed power density is not in the scope of this method, neither are controls relating, for instance, to occupancy detection. Provided the determination of the installed power density and control parameters using external sources, the internal loads by lighting and the lighting energy demand itself can be calculated. The energy demand for lighting and internal loads by lighting can then be taken into account in the overall building energy balance calculations: heating; ventilation; climate regulation and control (including cooling and humidification); and heating the domestic hot-water supply of buildings. For estimating the daylight supply and rating daylight-dependent artificial lighting control systems, a simple table-based calculation approach is provided. The simple method describes the division of a building into zones as required for daylight illumination-engineering purposes, as well as considerations on the way in which daylight supplied by vertical facade systems and rooflights is utilized and how daylight-dependent lighting control systems effect energy demand. Dynamic vertical facades with optional shading and light redirection properties are considered, i.e. allowing a separate optimization of facade solutions under direct insolation and under diffuse skies. For rooflighting systems standard, static solutions like shed rooflights and continuous rooflights are considered. The method is applicable for different latitudes and climates. For standard building zones (utilizations), operation times are provided. For detailed computer-based analysis (comprehensive calculation), minimum requirements are specified. To support overall building performance assessment, additional daylight performance indicators on the overall building level are provided.

Calcul de l'effet d'utiliser la lumière du jour à la demande énergétique net et finale pour l'éclairage

General Information

• Status: Published
• Publication Date: 16-Jun-2014
• ICS: 91.160.01 - Lighting in general
• Technical Committee: ISO/TC 274 - Light and lighting
• Drafting Committee: ISO/TC 274 - Light and lighting
• Current Stage: 9599 - Withdrawal of International Standard
• Due Date: 18-Nov-2024
• Completion Date: 18-Nov-2024

Relations

• Revised: ISO/CIE 10916:2024 - Light and lighting — Energy performance of lighting in buildings — Calculation of the impact of daylight utilization
• Effective Date: 23-Apr-2020

Standards Content (Sample)

DRAFT INTERNATIONAL STANDARD ISO/DIS 10916
ISO/TC 163/SC 2 Secretariat: SN
Voting begins on Voting terminates on

2013-07-03 2013-10-03
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION  •  МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ  •  ORGANISATION INTERNATIONALE DE NORMALISATION

Calculation of the impact of daylight utilization on the net and
final energy demand for lighting
Calcul de l'effet d'utiliser la lumière du jour à la demande énergétique net et finale pour l'éclairage

ICS 91.160.01
To expedite distribution, this document is circulated as received from the committee
secretariat. ISO Central Secretariat work of editing and text composition will be undertaken at
publication stage.
Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du
secrétariat du comité. Le travail de rédaction et de composition de texte sera effectué au
Secrétariat central de l'ISO au stade de publication.

THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY NOT BE
REFERRED TO AS AN INTERNATIONAL STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNOLOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT, WITH THEIR COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPORTING DOCUMENTATION.
©  International Organization for Standardization, 2013

ISO/DIS 10916
©  ISO 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any
means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission.
Permission can be requested from either ISO at the address below or ISO’s member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved

ISO/DIS 10916
Contents Page
Foreword . vi
Introduction . vii
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Symbols, indices and abbreviated terms . 4
4.1 Symbols . 4
4.2 Indices . 5
5 Proof calculation method . 5
5.1 Energy demand for lighting as function of daylight . 5
5.2 Subdivision of a building into zones . 7
5.3 Operating time . 8
5.4 Artificial lighting . 8
5.5 Constant illuminance control . 8
5.6 Daylight. 8
5.7 Occupancy dependency factor F . 9
O,n
6 Daylight Performance Indicator . 9
Annex A (informative) Simple calculation method . 10
A.1 General . 10
A.2 Building segmentation: Spaces benefiting from daylight . 12
A.3 Daylight supply factor for vertical facades . 14
A.3.1 Daylight factor classification . 14
A.3.2 Daylight supply factor . 19
A.4 Daylight supply factor for rooflights . 34
A.4.1 Daylight availability factor . 34
A.4.2 Daylight supply factor . 37
A.5 Daylight Responsive Control Systems . 43
A.6 Monthly evaluation method . 44
A.7 Determination of daytime and night-time hours . 45
A.8 Exemplary operation times of different building zone . 48
Annex B (normative) Comprehensive calculation . 50
Annex C (informative) Daylight performance indicator . 51
Annex D (informative) Examples . 52
D.1 Space with vertical façade . 52
D.2 Space with rooflights . 55
D.2.1 General . 55
D.2.2 Determination of the daylight availability factor F . 56
D,s
D.2.3 Determination of the annual and monthly final energy demand for lighting . 58
Bibliography . 61

ISO/DIS 10916
Tables
Table A.1 — Daylight availability classification as a function of the daylight factor D of the raw building
Ca,j
carcass opening . 19
Table A.2 — Representative locations on the northern and southern hemisphere with the corresponding
radiation ratios H /H . 22
dir glob
Table A.3 — Relative times t for not activated solar radiation and/or glare protection systems, as a
rel,D,SNA,j
function of the façade orientation, the geographic latitude  and the ratio H /H . 23
dir global
Table A.4 — Typical values of the transmittance  of transparent and translucent building
D65,SNA
components . 25
Table A.5 — Daylight supply factor F for sun shading not activated parameterized by D, , E ,
m
D,s,SNA,j
climate (H /H ), façade orientation, and geographic location for orientation South . 27
dir glob
Table A.6 — Daylight supply factor F for sun shading not activated parameterized by D, , E ,
D,s,SNA,j m
climate (H /H ), façade orientation, and geographic location for orientations East/ West . 29
dir glob
Table A.7 — Daylight supply factor F for sun shading not activated, parameterized by D, , E ,
m
D,s,SNA,j
climate (H /H ), façade orientation, and geographic location for orientation North . 31
dir glob
Table A.8 — System solutions (values to be applied for the period t ) . 33
rel,D,SA,j
Table A.9 — Typical values of the transmittance  , U and g of components frequently used in rooflight
D65
construction . 35
Table A.10 — External daylight factor D as a function of the façade slope  for a floor reflectance  of 0,2
a F B
(without building shading) . 38
Table A.11 — Dome skylight utilances  , expressed as a percentage, as a function of the space index k and
R
the geometry parameters of the annular support design . 39
Table A.12 — Shed rooflight utilances  , expressed as a percentage, as a function of the space index k and
R
the geometry parameters . 36
Table A.13 — Classification of daylight availability as a function of the daylight factor D . 37
j
Table A.14 — Daylight availability factor F of spaces with skylights as a function of the daylight availability
D,s,j
classification, the maintained illuminance E , façade orientation and incline, location  and climate
m
(H /H ) . 38
dir glob
Table A.15 — Correction factor F to account for the impact of daylight responsive control systems in a
D,c,j
zone n, as a function of the maintained illuminance E and the daylight availability classification . 44
m
Table A.16 — Monthly distribution key factors v for vertical façades . 44
Month,i
Table A.17 — Monthly distribution key factors v for rooflights . 45
Month,i
iv © ISO 2013 – All rights reserved

ISO/DIS 10916
Table A.18 — t and t as a function of latitude for typical operating hours from 8 am – 5 pm, weekends
day night
excluded . 47
Table A.19 — Data for usage of boundary conditions for non-residential buildings . 48
Table D.1 — Boundary conditions for the example with vertical façade . 53
Table D.2 — F , F , F and Q for system solutions 1, 2, 3 at the locations under
D,s,SNA,j D,s,SA,j D,s,j L,f
investigation . 55
Table D.3 — Monthly final energy demand for strip type rooflights . 60
Table D.4 — Monthly final energy demand for shed rooflights . 60

Figures
Figure 1 — Flowchart showing calculation of the energy demand for lighting . 7
Figure A.1 — Flowchart illustrating the simplified approach . 11
Figure A.2 — Three stage approach to determining the daylight supply factor F . 12
D,s,j
Figure A.3 — Impact of façade opening on daylight area for vertical façades . 14
Figure A.4 — Impact of roof opening on daylight area for rooflights . 14
Figure A.5 — Cross section diagram to illustrate the effect of the linear shading altitude angle  . 16
V,lV
Figure A.6 — Cross section diagram to illustrate the effect of the horizontal shading angle  . 16
V,hA
Figure A.7 — Cross section diagram to illustrate the effect of the vertical shading angle  . 17
Sh,vf
Figure A.8 — Illustration of the geometrical parameters used to define the well index wi . 18
Figure A.9 — Selected sites for which radiation ratios H /H are provided with assignment of latitude
dir glob
corridors and direct normal radiation. .
...

INTERNATIONAL ISO
STANDARD 10916
First edition
2014-06-15
Calculation of the impact of daylight
utilization on the net and final energy
demand for lighting
Calcul de l’effet d’utiliser la lumière du jour à la demande énergétique
net et finale pour l’éclairage
Reference number
©
ISO 2014
© ISO 2014
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2014 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols, indices, and abbreviated terms . 3
4.1 Symbols . 4
4.2 Indices . 5
5 Proof calculation method . 5
5.1 Energy demand for lighting as function of daylight . 5
5.2 Subdivision of a building into zones . 7
5.3 Operating time. 8
5.4 Artificial lighting . 8
5.5 Constant illuminance control . 8
5.6 Daylight. 8
5.7 Occupancy dependency factor F .
O,n 9
6 Daylight Performance Indicator . 9
Annex A (informative) Simple calculation method.10
Annex B (normative) Comprehensive calculation .53
Annex C (informative) Daylight performance indicator .54
Annex D (informative) Examples .55
Bibliography .63
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
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committee has been established has the right to be represented on that committee. International
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
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Attention is drawn to the possibility that some of the elements of this document may be the subject of
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any patent rights identified during the development of the document will be in the Introduction and/or
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to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 163, Thermal performance and energy use in the
built environment, Subcommittee SC 2, Calculation methods.
iv © ISO 2014 – All rights reserved

Introduction
This International Standard is part of a set of standards allowing to rate the overall energetic performance
of buildings. Facades and rooflights have a key impact on the building’s energy balance. This International
Standard supports the daylighting and lighting-energy-related analysis and optimization of facade and
rooflight systems. It was therefore specifically devised to establish conventions and procedures for the
estimation of daylight penetrating buildings through vertical facades and rooflights, as well as on the
energy consumption for electric lighting as a function of daylight provided in indoor spaces.
INTERNATIONAL STANDARD ISO 10916:2014(E)
Calculation of the impact of daylight utilization on the net
and final energy demand for lighting
1 Scope
This International Standard defines the calculation methodology for determining the monthly and
annual amount of usable daylight penetrating non-residential buildings through vertical facades and
rooflights and the impact thereof on the energy demand for electric lighting. This International Standard
can be used for existing buildings and the design of new and renovated buildings.
This International Standard provides the overall lighting energy balance equation relating the installed
power density of the electric lighting system with daylight supply and lighting controls (proof calculation
method).
The determination of the installed power density is not in the scope of this method, neither are controls
relating, for instance, to occupancy detection. Provided the determination of the installed power density
and control parameters using external sources, the internal loads by lighting and the lighting energy
demand itself can be calculated. The energy demand for lighting and internal loads by lighting can then
be taken into account in the overall building energy balance calculations:
— heating;
— ventilation;
— climate regulation and control (including cooling and humidification);
— heating the domestic hot-water supply of buildings.
For estimating the daylight supply and rating daylight-dependent artificial lighting control systems,
a simple table-based calculation approach is provided. The simple method describes the division of a
building into zones as required for daylight illumination-engineering purposes, as well as considerations
on the way in which daylight supplied by vertical facade systems and rooflights is utilized and how
daylight-dependent lighting control systems effect energy demand. Dynamic vertical facades with
optional shading and light redirection properties are considered, i.e. allowing a separate optimization
of facade solutions under direct insolation and under diffuse skies. For rooflighting systems standard,
static solutions like shed rooflights and continuous rooflights are considered. The method is applicable
for different latitudes and climates. For standard building zones (utilizations), operation times are
provided.
For detailed computer-based analysis (comprehensive calculation), minimum requirements are
specified.
To support overall building performance assessment, additional daylight performance indicators on the
overall building level are provided.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
CIE S 017/E:2011, ILV: International Lighting Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in CIE S 017/E:2011 ILV apply.
3.1
ballast
unit inserted between the supply and one or more discharge lamps, which by means of inductance,
capacitance, or a combination of inductance and capacitance, serves mainly to limit the current of the
lamp(s) to the required value
3.2
control system
various types of electrical and electronic systems including the following:
— systems used to control and regulate;
— systems to protect against solar radiation and/or glare;
— artificial lighting in relation to the currently available daylight;
— systems used to detect and record the presence of occupants
3.3
daylight factor
D
ratio of the illuminance at a point on a given plane due to the light received directly and indirectly from
a sky of assumed or known luminance distribution to the illuminance on a horizontal plane due to an
unobstructed hemisphere of this sky, where the contribution of direct sunlight to both illuminances is
excluded
[SOURCE: CIE S 017/E:2011 ILV, modified]
Note 1 to entry: CIE S 017/E:2011 defines the unit as 1. However, daylight factor is in practice, usually presented
in percent values.
3.4
electrical power of artificial lighting system
P
the total electrical power consumption of the lighting system in the considered space
3.5
illuminance
E
quotient of the luminous flux dΦ incident on an element of the surface containing the point, by the area
dA of that element
[SOURCE: CIE S 017/E:2011 ILV, modified]
–2
Note 1 to entry: Unit: lx = lm × m .
3.6
lamp
source made to produce optical radiation, usually visible
3.7
light reflectance
ratio of the reflected luminous flux to the incident luminous flux in the given conditions
Note 1 to entry: Unit: 1.
2 © ISO 2014 – All rights reserved

3.8
light transmittance
ratio of the transmitted luminous flux to the incident luminous flux in the given conditions
Note 1 to entry: Unit: 1.
3.9
luminaire
apparatus which distributes, filters, or transforms the light transmitted from one or more lamps and
which includes, except the lamps themselves, all the parts necessary for fixing and protecting the lamps
and, where necessary, circuit auxiliaries together with the means for connecting them to the electric
supply
[SOURCE: CIE S 017/E:2011 ILV]
3.10
luminous exposure
quotient of quantity of light dQ incident on an element of the surface containing the point over the given
v
duration, by the area dA of that element
–2
Note 1 to entry: Unit: lx × s = lm × s × m .
3.11
luminous flux
Φ
quantity derived from the radiant flux, Φ , by evaluating the radiation according to its action upon the
e
CIE standard photometric observer
Note 1 to entry: Unit: lm.
3.12
maintained illuminance
E
m
value below which the average illuminance over the specified surface is not allowed to fall
-2
Note 1 to entry: Unit: lx = lm × m .
3.13
obstruction
anything outside the window which prevents the direct view of part of the sky
3.14
rooflight
daylight opening on the roof or on a horizontal surface of a building
3.15
task area
partial area in the work plane in which the visual task is carried out
[SOURCE: CIE S 017/E:2011 ILV]
3.16
visual task
visual elements of the work being done
[SOURCE: CIE S 017/E:2011 ILV]
4 Symbols, indices, and abbreviated terms
For the pur
...