EN 721:2019

SLOVENSKI STANDARD
01-januar-2020
Nadomešča:
SIST EN 721:2005
Bivalna počitniška vozila - Zahteve za varnostno prezračevanje
Leisure accommodation vehicles - Safety ventilation requirements
Bewohnbare Freizeitfahrzeuge - Anforderungen an die Sicherheitslüftung
Véhicules habitables de loisirs - Exigences de ventilation de sécurité
Ta slovenski standard je istoveten z: EN 721:2019
ICS:
43.100 Osebni avtomobili. Bivalne Passenger cars. Caravans
prikolice in lahke prikolice and light trailers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 721
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2019
EUROPÄISCHE NORM
ICS 43.100 Supersedes EN 721:2004
English Version
Leisure accommodation vehicles - Safety ventilation
requirements
Véhicules habitables de loisirs - Exigences de Bewohnbare Freizeitfahrzeuge - Anforderungen an die
ventilation de sécurité Sicherheitslüftung
This European Standard was approved by CEN on 9 September 2019.

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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 721:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Requirements . 5
4.1 General . 5
4.2 Ingress of products of combustion. 5
4.3 Avoidance of obstructions . 7
4.4 Safety ventilator grilles . 7
5 Minimum free area of safety ventilation, by calculation . 7
5.1 General . 7
5.2 Sizes of safety ventilation openings in habitable compartments . 7
5.3 Alternative ventilation arrangements for caravan holiday homes over 20 m floor
area . 8
6 Testing . 10
6.1 Preparation . 10
6.2 Procedure. 10
6.3 Test report . 11
7 User's handbook . 12
Annex A (normative) Warning notice . 13

European foreword
This document (EN 721:2019) has been prepared by Technical Committee CEN/TC 245 “Leisure
accommodation vehicles”, the secretariat of which is held by AFNOR.
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 April 2020, and conflicting national standards shall be
withdrawn at the latest by April 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 721:2004.
In relation to EN 721:2004, the main technical changes are:
a) “ventilation” specified to “safety ventilation” throughout the document;
b) specified to flueless appliances;
c) normative references updated;
d) in 6.2 “Procedure”, procedure and calculation modified;
e) in 6.3 “Test report”, elements of the test report specified;
f) editorially modified;
g) Alternative ventilation arrangements have been added
h) Revision of chapter 5.2.1 “Habitable compartments containing non-room-sealed appliances” (the
table has been divided into two different tables)
i) deleted volume calculation for CO testing
j) 6.2.4 modified.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
1 Scope
This document specifies the minimum safety ventilation requirements for leisure accommodation
vehicles.
It provides alternative methods of calculation or testing of safety ventilation.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
EN 13878, Leisure accommodation vehicles — Terms and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13878 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
habitable compartment
compartment used for living purposes which is not solely utility room, sanitation compartment, walk in
storage or hallway
3.2
utility room
room limited in function to a washing machine and/ or tumble dryer
4 Requirements
4.1 General
Each habitable compartment, shall be provided with safety ventilation. Where trickle ventilation is used
in caravan holiday homes, the sanitary compartments shall be included. A habitable compartment that
includes a part that can be temporarily separated by a curtain shall be considered as a single
compartment.
The safety ventilation shall permit at least:
a) renewal of air for occupants;
b) supply of combustion air for appliances that are non-room-sealed;
c) evacuation of the products of combustion for flueless appliances, and
d) the necessary ventilation as prescribed by installed appliances manufacturer's instructions.
This requirement shall be considered fulfilled if, for each model:
e) the minimum free area of safety ventilation is provided, in accordance with Clause 5, or
f) the CO concentration in the air within each habitable compartment of the leisure accommodation
vehicle does not rise by more than 1 % (10 000 ppm) absolute above the background level, when
tested in accordance with Clause 6 and independently verified, and a permanent label is affixed
adjacent to the cooker (see Annex A).
If, when the vehicle is in motion, the free area of safety ventilation is reduced, then as the vehicle
becomes stationary the ventilators shall automatically return to the position in which the free area of
safety ventilation was calculated in accordance with Clause 5 or tested in accordance with Clause 6.
4.2 Ingress of products of combustion
Flue terminals shall be sited in accordance with the appliance manufacturer's instructions preferably on
the roof or in the wall of the vehicle.
Where national legislation does not forbid that the flue of an appliance is designed to discharge through
the floor, precautions shall be taken to prevent ingress of the products of combustion into the
habitation area through safety ventilation openings in the floor. The terminal shall be positioned as
close as possible to the sides or rear of the vehicle.
If there are underfloor flue terminals, it is recommended that low level safety ventilation openings are
positioned in the side of the vehicle and not in the floor.
Where the underfloor area is divided into distinct channels that project below the floor, e.g. by chassis
members or floor bearers, there shall be no safety ventilation openings in the same channel as any flue
outlet.
Flue terminals shall not be positioned within 500 mm of a refuelling point or fuel tank breather outlet
or any ventilator from the fuel system(s).
Flue terminals positioned on a wall or a roof (except for gas appliances of not more than 30 g/h LPG
consumption) shall not be fitted within 300 mm of a ventilator for the living space or an opening part of
a window (see Figure 1).
Key
1 Ventilator
2 Prohibited zone
l = 300 mm
Figure 1 — Prohibited zone for discharge openings for the products of combustion in relation to
ventilators
Where the flue terminal of an appliance (except for gas appliances of not more than 30 g/h LPG
consumption) is positioned vertically below an opening part of a window, the appliance shall be fitted
with an automatic shut-off device to prevent operation when the window is open (see Figure 2).

Key
1 Window
2 Prohibited zone
3 Floor
l = 300 mm
Figure 2 — Prohibited zone for discharge openings for the products of combustion in relation to
windows
4.3 Avoidance of obstructions
Safety ventilation openings shall be positioned so that they cannot be made ineffective by drapes,
curtains or other obstructions.
If the safety ventilation is provided to the interior through a cupboard, bed box or similar space, it shall
not be possible for the passage of air to be obstructed inadvertently e.g. by items stored in these spaces.
4.4 Safety ventilator grilles
The safety ventilation openings shall be protected by a grille that shall be accessible for cleaning. Access
may be gained by the use of a simple tool, e.g. a screwdriver.
5 Minimum free area of safety ventilation, by calculation
5.1 General
All safety ventilation grilles (see 4.4) shall be accounted for when providing the minimum free area of
safety ventilation.
When the high level safety ventilation is not provided by roof vents, the minimum high level safety
ventilation area shall be twice the values shown for roof vents in Table 1. The high level safety
ventilation openings, which are not roof vents, shall be not less than 1 750 mm from the interior floor
level of the leisure accommodation vehicle and not less than 300 mm above the upper surface of the
uncompressed mattress of the highest sleeping berth.
A combination of roof and wall vents is possible. To calculate the level of safety ventilation required,
subtract the level of safety ventilation given by the roof vent from the total required. Multiply the
remainder by two to give the level of safety ventilation required of the wall vents.
Low level safety ventilation openings shall be not more than 100 mm above the interior floor level.
5.2 Sizes of safety ventilation openings in habitable compartments
5.2.1 Habitable compartments containing non-room-sealed appliances
Safety ventilation openings shall conform to Table 1 for caravans and motorcaravans and to Table 2 for
caravan holiday homes.
Table 1 — Minimum sizes of safety ventilation openings in habitable compartments containing
non-room-sealed appliances in caravans and motorcaravans
Overall plan area Minimum high level safety Minimum low level safety
ventilation (Roof vents) ventilation
2 2 2
m mm mm
up to 5 7 500 1 000
...