SIST EN ISO 16484-4:2025
(Main)Building automation and control systems (BACS) - Part 4: Control applications (ISO 16484-4:2025)
Building automation and control systems (BACS) - Part 4: Control applications (ISO 16484-4:2025)
This document specifies control applications and function blocks focusing on, but not limited to, lighting, solar protection and heating, ventilation and air conditioning (HVAC) applications.
It describes how energy performance, comfort, and operational requirements of buildings are translated into functional specifications for integrated plant and room control.
Systeme der Gebäudeautomation - Steuerungsanwendung (ISO 16484-4:2025)
Dieses Dokument legt Steuerungsanwendungen und Funktionsblöcke, mit Schwerpunkt auf Beleuchtung, Sonnenschutz und Anwendungen für Heizung, Lüftung und Klimatisierung (HLK), fest.
Es beschreibt, wie Energieeffizienz, Komfort und betriebliche Anforderungen von Gebäuden auf funktionale Spezifikationen für integrierte Anlagen- und Raumautomation übertragen werden.
Systèmes d'automatisation et de contrôle des bâtiments (BACS) - Partie 4: Applications de contrôle (ISO 16484-4:2025)
Ce document spécifie les applications de contrôle et les blocs fonctionnels qui se concentrent, sans s'y limiter, sur les applications d'éclairage, de protection solaire et de chauffage, de ventilation et de climatisation (CVC).
Il décrit comment la performance énergétique, le confort et les exigences opérationnelles des bâtiments sont traduits en spécifications fonctionnelles pour le contrôle intégré des installations et des locaux.
Sistemi za avtomatizacijo in regulacijo stavb (BACS) - 4. del: Izvedba regulacije (ISO 16484-4:2025)
Ta dokument določa izvedbe regulacije in funkcionalne sklope, pri čemer se med drugim osredotoča na razsvetljavo, zaščito pred soncem ter ogrevanje, prezračevanje in klimatizacijo (HVAC). V njem je opisano, kako se energetske lastnosti, udobje in operativne zahteve za stavbe pretvorijo v funkcionalne specifikacije za integrirano regulacijo naprav in prostorov.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2025
Nadomešča:
SIST EN 17609:2022
Sistemi za avtomatizacijo in regulacijo stavb (BACS) - 4. del: Izvedba regulacije
(ISO 16484-4:2025)
Building automation and control systems (BACS) - Part 4: Control applications (ISO
16484-4:2025)
Systeme der Gebäudeautomation - Steuerungsanwendung (ISO 16484-4:2025)
Systèmes d'automatisation et de contrôle des bâtiments (BACS) - Partie 4: Applications
de contrôle (ISO 16484-4:2025)
Ta slovenski standard je istoveten z: EN ISO 16484-4:2025
ICS:
35.240.67 Uporabniške rešitve IT v IT applications in building
gradbeništvu and construction industry
91.140.01 Napeljave v stavbah na Installations in buildings in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 16484-4
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2025
EUROPÄISCHE NORM
ICS 91.040.01; 35.240.67 Supersedes EN 17609:2022
English Version
Building automation and control systems (BACS) - Part 4:
Control applications (ISO 16484-4:2025)
Systèmes d'automatisation et de contrôle des Systeme der Gebäudeautomation - Teil 4:
bâtiments (BACS) - Partie 4: Applications de contrôle Steuerungsanwendung (ISO 16484-4:2025)
(ISO 16484-4:2025)
This European Standard was approved by CEN on 21 August 2025.
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, Türkiye 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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16484-4:2025 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 16484-4:2025) has been prepared by Technical Committee ISO/TC 205
"Building environment design" in collaboration with Technical Committee CEN/TC 247 “Building
Automation, Controls and Building Management” the secretariat of which is held by SNV.
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 March 2026, and conflicting national standards shall
be withdrawn at the latest by March 2026.
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 17609:2022.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations 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, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 16484-4:2025 has been approved by CEN as EN ISO 16484-4:2025 without any
modification.
International
Standard
ISO 16484-4
First edition
Building automation and control
2025-08
systems (BACS) —
Part 4:
Control applications
Systèmes d'automatisation et de contrôle des bâtiments
(BACS) —
Partie 4: Applications de contrôle
Reference number
ISO 16484-4:2025(en) © ISO 2025
ISO 16484-4:2025(en)
© ISO 2025
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Published in Switzerland
ii
ISO 16484-4:2025(en)
Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 3
5 Functional specifications having an impact on energy performance, comfort, and
operational requirements of buildings . 3
5.1 Heating control .3
5.1.1 Emission control .3
5.1.2 Emission control for TABS (heating mode) .6
5.1.3 Control of distribution network hot water temperature (supply or return) .9
5.1.4 Control of distribution pumps in networks .10
5.1.5 Intermittent control of emission and/or distribution . 13
5.1.6 Heat generator control (combustion and district heating) .16
5.1.7 Heat generator control (heat pump) .18
5.1.8 Heat generator control (outdoor unit) .19
5.1.9 Sequencing of different heat generators . 20
5.1.10 Control of Thermal Energy Storage (TES) charging. 23
5.1.11 Hydronic balancing heating distribution (including contribution to balancing to
the emission side) .24
5.2 Domestic hot water (DHW) supply control . 26
5.2.1 Control of DHW storage charging with direct electric heating or integrated
electric heat pump . 26
5.2.2 Control of DHW storage charging using hot water generation .27
5.2.3 Control of DHW storage charging with solar collector and supplementary heat
generation . 29
5.2.4 Control of DHW circulation pump .31
5.3 Cooling control .32
5.3.1 Emission Control .32
5.3.2 Emission control for TABS (cooling mode) . 35
5.3.3 Control of distribution network chilled water temperature (supply or return) .37
5.3.4 Control of distribution pumps in hydraulic networks . 38
5.3.5 Intermittent Control of Emission and/or Distribution .41
5.3.6 Interlock between heating and cooling control of emission and/or distribution . 44
5.3.7 Generator control for cooling .45
5.3.8 Sequencing of different chillers (generators for chilled water) . 46
5.3.9 Control of Thermal Energy Storage (TES) charging. 48
5.3.10 Hydronic balancing cooling distribution (including contribution to balancing to
the emission side) . 49
5.4 Ventilation and air conditioning control .51
5.4.1 Supply air flow control at the room level.51
5.4.2 Room air temperature control by the ventilation system (all-air systems;
combination with static systems as cooling ceiling, radiators etc.) . 53
5.4.3 Coordination of room air temperature control by ventilation and by static
systems . 55
5.4.4 Outside air flow control . 56
5.4.5 Air flow or pressure control at the air handler level . .57
5.4.6 Heat recovery control (icing protection) . 60
5.4.7 Heat recovery control (prevention of overheating) .61
5.4.8 Free mechanical cooling .62
5.4.9 Supply air temperature control at the air handling unit level . 64
5.4.10 Humidity control . 65
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ISO 16484-4:2025(en)
5.5 Lighting control . 66
5.5.1 Occupancy control . 66
5.5.2 Light level/Daylight control (daylight harvesting). 69
5.6 Blind control .71
5.6.1 Type 1 — Motorized operation of blind with manual control .71
5.6.2 Type 2 — Motorized operation of blind with automatic control . 72
5.6.3 Type 3 — Combined light/blind/HVAC control . 73
6 Functional elements . 74
6.1 Sensor functions.74
6.1.1 Air quality measurement .74
6.1.2 Air temperature measurement. 75
6.1.3 Dewpoint monitoring .76
6.1.4 Humidity measurement . 77
6.1.5 Brightness measurement . 78
6.1.6 Precipitation detection . 78
6.1.7 Presence detection . 79
6.1.8 Window monitoring . 80
6.1.9 Wind speed measurement . 81
6.1.10 Real-time clock . 82
6.1.11 Air volume flow measurement. 82
6.1.12 Partition wall position sensor . 83
6.2 Actuator functions . 84
6.2.1 Solar protection actuator . 84
6.2.2 Drive actuator . 85
6.2.3 Lighting actuator . . . 86
6.3 Display and user operation functions . 88
6.3.1 Operate lighting . 88
6.3.2 Operate solar protection . 89
6.3.3 Operate Drive . 89
6.3.4 Set Temperature setpoint . 90
6.3.5 Display Current Temperature .91
6.3.6 Select room utilisation type . 92
6.3.7 Set presence . 93
6.4 Control functions . 94
6.4.1 Presence evaluation. 94
6.4.2 Predefined operation setting (scenario) . 95
6.4.3 Schedule . 96
6.4.4 Manual lighting control . 97
6.4.5 Timed lighting control . 98
6.4.6 Partition wall control . 99
6.4.7 Occupancy dependent lighting control . 100
6.4.8 Daylight-dependent lighting . 101
6.4.9 Constant-light control . 103
6.4.10 Twilight control . 105
6.4.11 Priority control . 106
6.4.12 Automatic twilight control . 108
6.4.13 Automatic solar control (simple solar protection) . 109
6.4.14 Slat tracking (complex solar protection) . . 111
6.4.15 Shadow correction . 113
6.4.16 Automatic thermal control .114
6.4.17 Weather protection . 115
6.4.18 Energy mode selection .117
6.4.19 Energy mode selection with start optimisation . 118
6.4.20 Setpoint calculation . 120
6.4.21 Function selection . 122
6.4.22 Temperature control (heating/cooling) . 124
6.4.23 Room supply air temperature cascade control . 126
6.4.24 Fan control .128
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ISO 16484-4:2025(en)
6.4.25 Sequence control . 130
6.4.26 Control value limiting . 131
6.4.27 Air quality control . 133
6.4.28 Night-time cooling . 135
6.4.29 Volume flow control . 136
6.4.30 Sun position calculation . 138
6.4.31 Weather hazard assessment . 138
6.4.32 Wind hazard detection . 139
6.4.33 Icing hazard detection . . 140
6.4.34 Rain hazard detection .141
6.4.35 Solar edge tracking . . .141
6.4.36 Solar edge and slat tracking .142
6.4.37 Window state evaluation/Window group monitoring .143
6.4.38 Electric heating actuator. 144
6.5 Data types and notation of identifiers and types used in function blocks .145
Bibliography .147
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ISO 16484-4:2025(en)
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.
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 editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 205, Building environment design, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 247,
Building Automation, Controls and Building Management, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
A list of all parts in the ISO 16484 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO 16484-4:2025(en)
Introduction
Buildings are built and operated to serve a specific purpose, e.g. as an office workspace, a manufacturing
floor, or a data centre. In each case, the usage of the space requires specific environmental conditions, e.g.
temperature, light level or air quality.
Increasing the efficient usage of energy to provide these environmental conditions is a key aspect of building
design as addressed in ISO 52120-1.
Energy efficiency requirements cannot be fulfilled by optimizing the primary systems of a building alone.
A holistic view on the building and especially on the room control systems for lighting, solar protection and
heating, ventilation and air conditioning (HVAC) is the basis for optimizing the energy efficiency of buildings.
This requires integration of the room and building controls and management systems from the design phase
through installation and commissioning to the building operation.
The planning process for the technical infrastructure of a building and its spaces includes several steps
starting with a rough set of requirements. With each step in the planning process the design becomes more
detailed. Firstly, basic design choices or decisions allow for a budget estimate. These first design choices can
be documented as depicted in Figure 1.
SOURCE SN 502411:2016 / SIA 411:2016
Figure 1 — Example for documentation of design choices for technical infrastructure of a building
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ISO 16484-4:2025(en)
Figure 1 shows equipment used for the different technical building disciplines (e.g. heating, cooling,
ventilation, lighting, solar protection) in the space including energy related interconnections between the
equipment of the respective disciplines. The schema depicts source/sink, conversion, storage, distribution,
and emission elements and their interconnections in a simple manner. This is a high-level view on the
mechanical and electrical equipment. It does not yet include the automation requirements associated with
the equipment.
In a further planning step, the control functions (BAC functions) associated with the technical infrastructure
equipment of a building are added as depicted in Figure 2.
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ISO 16484-4:2025(en)
SOURCE SN 502411:2016 / SIA 411:2016
Figure 2 — Example for documentation of design choices for technical infrastructure and associated
control functions of a building
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ISO 16484-4:2025(en)
The column “usage/operation” contains control functions used either for user interaction with the technical
building infrastructure in the space or for super-ordinated (e.g. building-wide) functions and requirements
or both.
Whereas the control functions are determined by the technical building equipment and the user operation
interface in general, the sophistication of these control functions is determined by the desired level of
energy efficiency of a building or comfort and operational requirements. Hence, in both views, the desired
level of energy efficiency of a building and the comfort and operational requirements, are considered
and documented such that this documentation serves as a requirement specification for building control
applications (e.g. heating, cooling, ventilation, lighting, solar protection) in a space.
In Figure 2, BAC functions have been added to the equipment. The labels refer to BAC functions listed in
ISO 52120-1:2021, Table 5. These BAC functions are not specified in detail in ISO 52120-1.
Clause 5 of this document provides a method to transfer energy performance, comfort, and operational
requirements as defined in ISO 52120-1:2021 into a more detailed specification of building automation
functions.
ISO 52120-1:2021, Table 5, contains a list of functions contributing to achieve the desired level of energy
performance. Whereas ISO 52120-1 only provides a very brief description of the functionality, Clause 5
contains a more detailed description.
NOTE Application of automated control improves the energy performance of buildings. Clause 5 of this document
covers automated control applications only. Any manual or non-automated control listed in ISO 52120-1:2021, Table 5,
is not covered in this document.
For the purpose of clarity, each subclause in Clause 5 identifies the corresponding entry in ISO 52120-1:2021,
Table 5 directly after the sub-clause heading.
The more detailed description includes information about mandatory and optional inputs as well as
mandatory and optional outputs for the control function. The control function is not described in detail but
rather is a “black box” as the actual implementation can be project or manufacturer specific.
Figure 3 provides an informative schematic view with the function (box), mandatory (blue) and optional
(grey) inputs and mandatory (blue) and optional (grey) outputs. The informative schematic drawing
also shows if inputs can be controlled, e.g. by manual operation or by a schedule, and if output values are
associated, e.g. with an alarm or a trend.
Figure 3 — Informative depiction of control application scheme for heating control — Emission
control — Type 1: Central automatic control
Clause 5 contains in each sub-clause a brief description of the control function itself, the target of the
function, different operating modes, where applicable, and a description of the inputs and outputs of the
function. Optionally, parameters and implementation equipment may be described.
For some of these functions, more than one version is described, covering different technological
implementations.
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ISO 16484-4:2025(en)
Building control functions may be associated with a specific zone, a room, a building segment, or the whole
building.
The result of applying Clause 5 is a collection of building automation control function blocks. This does not
yet depict how these blocks work in detail or how they are linked to each other. A more detailed control
scheme description can be provided using the function blocks described in Clause 6.
Clause 6 of this document provides function blocks, which can be used to describe building control functions
in more detail independent of a specific building control system or vendor.
Applications can be described by a combination of sensor input, actuator output, user interaction, and
control and monitoring functions. Certain functions in a room (e.g. presence detection) can be shared by
two or more applications. A common set of function blocks covering sensor input, actuator output, user
interaction, and control functions for the different applications in a room serves as the basis for describing
room automation, controls and management systems.
NOTE Room automation is coordinated control of lighting, solar protection, heating/ventilation/air conditioning
devices and systems in a room providing the desired comfort level with maximum energy efficiency. Using a typical
example, Figure 4 shows the relationship between sensor, display/operation, control and actuator functions.
Information exchanged between functions is provided from outputs to inputs. Physical inputs and outputs associated
with sensor and actuator functions are not depicted in the Figure 3. As some functions can require parameters, these
are also depicted in each function block.
Figure 4 — Relationship between automation functions (typical example)
A sensor function typically includes a physical input (e.g. a temperature sensor, not depicted in Figure 4) and
provides a logical output (OUTPUT of the Sensor function block in Figure 4) for use by other functions.
A display and operation function includes physical inputs or outputs depending on its functionality and
provides logical inputs for display purposes and logical outputs for use by other functions (Display and
Operation function block in Figure 4).
Control functionality as depicted in Figure 4 is assigned to specific control functions with one or more
logical inputs (INPUT 1 and INPUT 2 of the Control function block in Figure 4) and at least one logical output
(OUTPUT of the Control function block in Figure 4). Control functions are not directly associated with
physical inputs or outputs.
Actuator functionality is assigned to specific actuator functions. An actuator function typically includes a
physical output (controlling a valve for example) and provides a logical input (INPUT of the Actuator function
in Figure 4) and logical output. This logical output can be used as a feedback status information.
The generalized description format used in Clause 6 for functions includes a brief description of the function,
of the physical input(s), of the logical input(s) expected from other functions, of the logical output(s) provided
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ISO 16484-4:2025(en)
to other functions, and of the physical output(s). In addition, parameters are listed that are required to more
precisely define the function for a specific project.
The description of the functions blocks follows this uniform scheme:
— short description of the function;
— physical input(s);
— logical input(s);
— logical output(s);
— physical output(s);
— parameters (optional).
The list of functions can be extended where necessary.
xii
International Standard ISO 16484-4:2025(en)
Building automation and control systems (BACS) —
Part 4:
Control applications
1 Scope
This document specifies control applications and function blocks focusing on, but not limited to, lighting,
solar protection and heating, ventilation and air conditioning (HVAC) applications.
It describes how energy performance, comfort, and operational requirements of buildings are translated
into functional specifications for integrated plant and room control.
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.
ISO 52120-1:2021, Energy performance of buildings — Contribution of building automation, controls and
building management — Part 1: General framework and procedures
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 52120-1 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
display function
presentation of information coming from an actuator, control, monitoring or sensor function in a visible
format understandable by a human user
Note 1 to entry: Information may be displayed in text form (e.g. 18 °C, 100 %) or in a graphical form (e.g. light blue for
cool, bar graph).
3.2
energy efficiency
ratio or other quantitative relationship between an output of performance, service, goods or energy, and an
input of energy
EXAMPLE Efficiency conversion energy; energy required/energy used; output/input; theoretical energy used to
operate/energy used to operate.
Note 1 to entry: Both input and output need to be clearly specified in quantity and quality. Additionally, they need to
be measurable.
[SOURCE: ISO 52120-1:2021, 3.9]
ISO 16484-4:2025(en)
3.3
building automation
coordinated control of lighting, solar protection, heating, ventilation, and air conditioning (HVAC) devices
and systems in a building providing the desired comfort level with maximum energy efficiency
Note 1 to entry: Coordinated control may also encompass access control via information links from those devices and
systems to other building control devices and systems.
3.4
logical input
interface of a function receiving data from an output of another function
3.5
logical output
interface of a function sending data to an input of another function
3.6
operation function
means for input of information by a human user intended for use by an actuator, control, monitoring or
display function
Note 1 to entry: Operation of, for example, a wall switch or touch panel area, may be used as input.
3.7
plant
equipment for generation of either hot or cold water, or conditioned air, or both
3.8
room
one or more zones with a joint perimeter typically determined by walls or other types of partitions
Note 1 to entry: Typically, a room is a
...
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