EN ISO 15927-5:2004

SLOVENSKI STANDARD
01-februar-2005
Higrotermalne značilnosti stavb - Izračun in predstavitev podnebnih podatkov - 5.
del: Podatki za določitev računske potrebne toplote za ogrevanje prostorov (ISO
15927-5:2004)
Hygrothermal performance of buildings - Calculation and presentation of climatic data -
Part 5: Data for design heat load for space heating (ISO 15927-5:2004)
Wärme- und feuchteschutztechnisches Verhalten von Gebäuden - Berechnung und
Darstellung von Klimadaten - Teil 5: Daten zur Bestimmung der Norm-Heizlast für die
Raumheizung (ISO 15927-5:2004)
Performance hygrothermique des bâtiments - Calcul et présentation des données
climatiques - Partie 5: Données pour la charge calorifique de conception pour le
chauffage des locaux (ISO 15927-5:2004)
Ta slovenski standard je istoveten z: EN ISO 15927-5:2004
ICS:
91.120.10 Toplotna izolacija stavb Thermal insulation of
buildings
91.120.30 Zaščita pred vlago Waterproofing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 15927-5
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2004
ICS 07.060; 91.120.10
English version
Hygrothermal performance of buildings - Calculation and
presentation of climatic data - Part 5: Data for design heat load
for space heating (ISO 15927-5:2004)
Performance hygrothermique des bâtiments - Calcul et Wärme- und feuchteschutztechnisches Verhalten von
présentation des données climatiques - Partie 5: Données Gebäuden - Berechnung und Darstellung von Klimadaten -
pour la charge calorifique de conception pour le chauffage Teil 5: Bemessungstemperaturen der Außenluft im Winter
des locaux (ISO 15927-5:2004) und zugehörige Winddaten (ISO 15927-5:2004)
This European Standard was approved by CEN on 27 October 2004.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15927-5:2004: E
worldwide for CEN national Members.

Foreword
This document (EN ISO 15927-5:2004) has been prepared by Technical Committee ISO/TC 163
"Thermal insulation" in collaboration with Technical Committee CEN/TC 89 “Thermal
performance of buildings and building components”, the secretariat of which is held by SIS.

This European Standard shall be given the status of a national standard, either by publication of
an identical text or by endorsement, at the latest by May 2005, and conflicting national standards
shall be withdrawn at the latest by May 2005.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,
Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Endorsement notice
The text of ISO 15927-5:2004 has been approved by CEN as EN ISO 15927-5:2004 without any
modifications.
INTERNATIONAL ISO
STANDARD 15927-5
First edition
2004-11-15
Hygrothermal performance of
buildings — Calculation and presentation
of climatic data —
Part 5:
Data for design heat load for space
heating
Performance hygrothermique des bâtiments — Calcul et présentation
des données climatiques —
Partie 5: Données pour la charge calorifique de conception pour le
chauffage des locaux
Reference number
ISO 15927-5:2004(E)
©
ISO 2004
ISO 15927-5:2004(E)
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ii © ISO 2004 – All rights reserved

ISO 15927-5:2004(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references . 1
3 Terms, definitions, symbols and units . 1
4 Methods of calculation . 2
5 Coincident wind speed. 4
6 Dominant wind direction . 4
7 Reference altitude. 4
8 Presentation of data. 5
9 Data representing a geographical area, region or zone. 6

ISO 15927-5:2004(E)
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 through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 15927 was prepared by the European Committee for Standardization (CEN) in collaboration with
Technical Committee ISO/TC 163, Thermal performance and energy use in the built environment,
Subcommittee SC 2, Calculation methods, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
ISO 15927 consists of the following parts, under the general title Hygrothermal performance of buildings —
Calculation and presentation of climatic data:
 Part 1: Monthly means of single meteorological elements
 Part 5: Data for design heat load for space heating
The following parts are under preparation:
 Part 4: Data for assessing the annual energy for cooling and heating systems
 Part 6: Accumulated temperature differences (degree days)

iv © ISO 2004 – All rights reserved

ISO 15927-5:2004(E)
Introduction
The choice of design heat load for space heating is a matter of balancing user needs against cost. On the one
hand, users expect a heating system to maintain the internal temperatures needed for health and comfort; on
the other hand, very high heating demand arises from time to time, when a meteorological extreme occurs. It
may be uneconomic to design heating systems for rare extremes, as this can lead to high capital (initial) cost
and to lower operational efficiency of the system.
The practical solution is to choose an infrequent, but not extreme, climatological value as the basis for the
design load. This means that from time to time heat demand will exceed the system capacity, with the result
that internal temperatures will be lower than desired, or that supplementary heating will be needed (e.g. from
local heaters). The methods of calculation in this part of ISO 15927 include a standard return period or
frequency, which is judged to give an acceptable balance between risk of inadequate performance and cost.
The definition of winter external design temperatures also needs to reflect the interaction between buildings
and their external environment. Buildings possess thermal inertia and do not respond instantly to changes in
weather conditions. The time delay (or lag) before internal conditions are significantly affected varies among
different types of construction and heating methods. To allow for this, winter external design temperatures,
calculated according to this part of ISO 15927, can be defined over a range of periods from as short as 1 h to
as long as 4 days.
The influence of wind is important, as infiltration can cause a large proportion of heat loss from buildings that
are not airtight; this is especially true in climates where infrequent, low temperatures are associated with high
wind speeds. This part of ISO 15927 specifies that average coincident wind speed and range of directions are
determined for the conditions of the winter external design temperature.

INTERNATIONAL STANDARD ISO 15927-5:2004(E)

Hygrothermal performance of buildings — Calculation and
presentation of climatic data —
Part 5:
Data for design heat load for space heating
1 Scope
This part of ISO 15927 specifies the definition, method of calculation and method of presentation of the
climatic data to be used in determining the design heat load for space heating in buildings. These include
— the winter external design air temperatures;
— the relevant wind speed and direction, where appropriate.
Heat loss through the ground, which also contributes to the heat load for buildings, depends on longer-term
1)
temperature changes; methods for calculating ground heat loss are given in ISO 13370 .
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 6243, Climatic data for building design — Proposed system of symbols
World Meteorological Organization: Guide to Meteorological Instruments and Methods of Observation,
th
6 Edition, WMO — No. 8, 1996
3 Terms, definitions, symbols and units
3.1 Terms and definitions
For the purposes of this standard, the terms and definitions given in ISO 6243 and the following apply.
3.1.1
design heat load
maximum heat output required from the heating system of a building, in order to maintain required internal
temperatures without supplementary heating
3.1.2
winter external design temperature
low external air temperature with a defined return period, used to determine the design heat load of a building

1) ISO 13370, Thermal performance of buildings — Heat transfer via the ground — Calculation methods.
ISO 15927-5:2004(E)
3.1.3
c
...