work package 1 perceived barriers to natural ventilation design of office buildings the objective of...

Work Package 1Work Package 1Perceived Barriers toPerceived Barriers to

Natural Ventilation DesignNatural Ventilation Designof Office Buildingsof Office Buildings

The objective of the study was to identify perceived barriers restricting the implementation of natural or simple fan assisted ventilation systems in the design of new office

buildings and in the refurbishment of existing

office buildings.

The objective of the study was to identify perceived barriers restricting the implementation of natural or simple fan assisted ventilation systems in the design of new office

buildings and in the refurbishment of existing

office buildings.

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ObjectiveObjective

Barriers to Barriers to natural natural

ventilationventilation

InterviewsInterviews

KnowledgeKnowledge

ExperienceExperience

Guidelines & Guidelines & productsproducts

User satisfact.User satisfact.

PerformancePerformance

ControllabilityControllability

CostsCosts

FutureFuture

RestrictionsRestrictions

DesignDesign

RESULTS of RESULTS of interviewsinterviews

Conclusions & Conclusions & recommendationsrecommendations

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InterviewsInterviewsintervieweesinterviewees

Interview of 107 designers and decision makers:

42 architects 24 consultant engineers 11 contractors 9 developers 14 owners 7 governmental

decision

makers

Interview of 107 designers and decision makers:

42 architects 24 consultant engineers 11 contractors 9 developers 14 owners 7 governmental

decision

makers

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ObjectiveObjective




KnowledgeKnowledge






CostsCosts

FutureFuture


DesignDesign



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InterviewsInterviewsquestionnairesquestionnaires

Structured interviews based on questionnaires. Questionnaires completed by the interviewee and the interviewer

together. Focus on:

general knowledge viewpoints experience and perceived problems.

Focus on decisions actually taken in specific building projects. Allows for additional comments, remarks and viewpoints.

Structured interviews based on questionnaires. Questionnaires completed by the interviewee and the interviewer

together. Focus on:

general knowledge viewpoints experience and perceived problems.

Focus on decisions actually taken in specific building projects. Allows for additional comments, remarks and viewpoints.

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ObjectiveObjective




KnowledgeKnowledge






CostsCosts

FutureFuture


DesignDesign



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InterviewsInterviewsusersusers

Interviews with users of office buildings are not included in this study.

The users perception is part of Work Package 2: ‘Performance of naturally ventilated buildings’, where physical parameters are also measured and compared with the users responses.

Interviews with users of office buildings are not included in this study.

The users perception is part of Work Package 2: ‘Performance of naturally ventilated buildings’, where physical parameters are also measured and compared with the users responses.

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ObjectiveObjective




KnowledgeKnowledge






CostsCosts

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InterviewsInterviewsCountries & ClimatesCountries & Climates

7 central and north European countries with moderate or cold climates: Belgium (B) Denmark (DK) Switzerland (CH) Norway (N) The Netherlands (NL) Sweden (S) United Kingdom (UK)

7 central and north European countries with moderate or cold climates: Belgium (B) Denmark (DK) Switzerland (CH) Norway (N) The Netherlands (NL) Sweden (S) United Kingdom (UK)

CH

BNL

S

UK

DK

N

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Perception of own knowledgePerception of own knowledge

Nearly all the interviewees know less about specially designed natural ventilation than they know about mechanical ventilation.

On average the interviewees have nearly the same level of knowledge of traditional natural ventilation as on mechanical ventilation.

Nearly all the interviewees know less about specially designed natural ventilation than they know about mechanical ventilation.

On average the interviewees have nearly the same level of knowledge of traditional natural ventilation as on mechanical ventilation.

A specific 5 point scale ranking from 1: None to 5: Thorough is used to indicate the level of knowledge.

All is the average of all groups except the governmental decision makers, with the professional groups weighted equal.

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4

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Arc

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cts

Con

s.e

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Con

tra

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Dev

elo

p.

Ow

ne

rs All

Gov

. D

ec.

Non

e

T

horo

ugh

Mech. vent.

Trad. NatVent

Spec. NatVent

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The interviewees’ experienceThe interviewees’ experience

Most of the interviewees have considerable experience of mechanical ventilation.

Many of the interviewees have worked with traditional natural ventilation.

Their experience with special designed natural ventilation is very limited.

Most of the interviewees have considerable experience of mechanical ventilation.

Many of the interviewees have worked with traditional natural ventilation.

Their experience with special designed natural ventilation is very limited.

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20

40

60

80

100

Mech. vent. Trad. NatVent Spec. NatVent

Per

cen

tBDKCHNNLSUKAll

The relative experience is the per cent of mechanical or natural ventilated offices designed, constructed or owned.

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Guidelines & productsGuidelines & products

Nearly all of the interviewees reported that design guidelines and products were more readily available for mechanical ventilation systems than natural ventilation systems.

The general opinion among the interviewees is that there are few good sources of information about natural ventilation

Nearly all of the interviewees reported that design guidelines and products were more readily available for mechanical ventilation systems than natural ventilation systems.

The general opinion among the interviewees is that there are few good sources of information about natural ventilation

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5

Guidelines Products

P

oo

r

E

xce

llen

t

Natur., Cellular

Natur., Open plan

Mech., Cellular

Mech., Open plan

A specific 5 point scale ranking from 1: Poor to 5: Excellent is used to indicate the interviewees’ perceptions

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Expected user satisfactionExpected user satisfaction

On average, the interviewees expect the same level of user satisfaction for naturally and mechanically ventilated cellular offices.

The interviewees expect higher level of user satisfaction in natural ventilated cellular offices than in natural ventilated open plan offices.

The level of user satisfaction expected In mechanically ventilated offices is the same as in cellular offices as in open plan offices.

On average, the interviewees expect the same level of user satisfaction for naturally and mechanically ventilated cellular offices.

The interviewees expect higher level of user satisfaction in natural ventilated cellular offices than in natural ventilated open plan offices.

The level of user satisfaction expected In mechanically ventilated offices is the same as in cellular offices as in open plan offices.

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1

2

3

4

5

User satisfaction

P

oo

r

E

xce

lle

nt

Natur., Cellular

Natur., Open plan

Mech., Cellular

Mech., Open plan

A specific 5 point scale ranking from 1: Poor to 5: Excellent is used to indicate the expected user satisfaction

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Expected performance in practiceExpected performance in practice

In general, the interviewees expect mechanical ventilation systems to perform better than natural ventilation systems with regard to cooling effectiveness, draught minimisation, ability to remove odours, ability to prevent ingress of odours and ability to insulation against external noise.

Regarding the generation or transmission of internal noise the interviewees expect the same level of performance from both types of ventilation system.

In general, the interviewees expect mechanical ventilation systems to perform better than natural ventilation systems with regard to cooling effectiveness, draught minimisation, ability to remove odours, ability to prevent ingress of odours and ability to insulation against external noise.

Regarding the generation or transmission of internal noise the interviewees expect the same level of performance from both types of ventilation system.

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1

2

3

4

5

Coolin

geff

ect

.

Dra

ught

Rem

ove

odour

Ingre

ssodour

Ext

ern

nois

e

Inte

rnnois

e

P

oo

r

E

xce

llen

t

Natur., Cellular

Natur., Open plan

Mech., Cellular

Mech., Open plan

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Expected controllabilityExpected controllability

In general the interviewees expect a high degree of centralised control with mechanical ventilation systems and less centralised control of natural ventilation systems: especially in cellular offices.

The level of local and individual control of ventilation expected is higher in cellular offices than in open plan offices.

In general the interviewees expect a high degree of centralised control with mechanical ventilation systems and less centralised control of natural ventilation systems: especially in cellular offices.

The level of local and individual control of ventilation expected is higher in cellular offices than in open plan offices.

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1

2

3

4

5

Central Local Individual

Po

or

Exce

lle

nt

Natur., Cellular

Natur., Open plan

Mech., Cellular

Mech., Open plan

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Expected costsExpected costs

Most interviewees expect higher installation, higher running and higher maintenance costs for mechanical ventilation than for natural ventilation.

If mechanical ventilation is installed in a building it will account for a significant proportion of the total construction costs.

Installation costs for a natural ventilation systems could be high if the system requires chimneys, more floor area or additional volume.

Most interviewees expect higher installation, higher running and higher maintenance costs for mechanical ventilation than for natural ventilation.

If mechanical ventilation is installed in a building it will account for a significant proportion of the total construction costs.

Installation costs for a natural ventilation systems could be high if the system requires chimneys, more floor area or additional volume.

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1

2

3

4

5

Installation Running Maintenance

In

exp

en

siv

e

Exp

en

siv

eNatur., Cellular

Natur., Open plan

Mech., Cellular

Mech., Open plan

A specific 5 point scale ranking from 1: Inexpensive to 5: Expensive is used to indicate the interviewees’ perception of the costs.

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Expected future use of natural Expected future use of natural ventilationventilation

In general, architects have the highest expectations of the increasing use of natural ventilation in offices.

On an average basis, it is only the governmental decisions makers who anticipate a decrease in the use of natural ventilation.

In general, architects have the highest expectations of the increasing use of natural ventilation in offices.

On an average basis, it is only the governmental decisions makers who anticipate a decrease in the use of natural ventilation.

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Arc

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ns.

en

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Co

ntr

acto

rs

De

ve

lop

ers

Ow

ne

rs All

Go

v.

De

c.

D

ecre

ase

Un

ch

an

ge

In

cre

ase

Min. country

Average

Max. country

The expectation is indicated on a specific 5 points scale ranking from 1: Significant decreasing over 3: Unchanged to 5: Significant increasing.

All is the average of all groups except the governmental decision makers, with the professional groups weighted equal.

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Perceived restrictions in regulations, Perceived restrictions in regulations, codes, norms and standardscodes, norms and standards

The perception that regulations limit the use of natural ventilation varies from country to country.

In Belgium, Norway and Sweden the interviewees report that there are significant barriers to the use of natural ventilation.

In other countries, such restriction are perceived to be more limited.

The perception that regulations limit the use of natural ventilation varies from country to country.

In Belgium, Norway and Sweden the interviewees report that there are significant barriers to the use of natural ventilation.

In other countries, such restriction are perceived to be more limited.

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1

2

3

4

5

Architects Cons. eng. All Gov. Dec.

N

on

e

Co

mp

reh

en

sive

BDKCHNNLSUK

The perception of restrictions is indicated on a specific 5 points scale ranking from 1: None to 5: Comprehensive

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Critical parameters for the designCritical parameters for the design

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Win

ter

tem

p.

Ind.

air

qual

.

Dra

ught

, w

int.

Sum

mer

tem

p.

Sol

ar lo

ads

Int.

hea

t lo

ads

Dra

ught

, su

m.

Indi

v. c

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ol

Inte

rnal

noi

se

Ext

erna

l noi

se

Int.

pol

lutio

ns

Ext

. po

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ns

Fire

reg

ulat

.

Sec

urity

Con

st.

cost

s

Ope

r. c

osts

Mai

nt.

cost

s

L

ow

H

igh

Min. country

Average

Max. country

Each interviewee was allowed to point out a maximum of 5 critical parameters and was asked to prioritise them from 1: Low to 5: High.

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The most critical parametersThe most critical parameters

For many of the interviewees the most critical parameter is summer-time room temperature or construction costs.

Other give the highest priority to solar heat gains, indoor air quality and indoor pollution.

Several of the interviewees identified external noise and operation costs parameters.

For many of the interviewees the most critical parameter is summer-time room temperature or construction costs.

Other give the highest priority to solar heat gains, indoor air quality and indoor pollution.

Several of the interviewees identified external noise and operation costs parameters.

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CostsCosts

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Influence on designInfluence on design

Architects, consultant engineers and owners have the greatest influence on the choice of design.

Architects, consultant engineers and owners have the greatest influence on the choice of design.

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1

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3

4

5

Arc

hite

ct

Co

ns.

Eng

ine

er

Co

ntr

acto

r

Ow

ner

De

ve

lope

r

Investe

r

Users

Build

. site

Co

de

sLo

w

Hig

h

Min. country

Average

Max. country

Each interviewee was allowed to point out a maximum of 5 persons or conditions and was asked to prioritise them from 1: Low to 5: High.

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Conclusions Conclusions & & RecommendationsRecommendations

The interviews identify significant lack of knowledge and experience of specially designed natural ventilation in office buildings compared to the knowledge and experience of mechanical ventilation.

The interviews identify significant lack of knowledge and experience of specially designed natural ventilation in office buildings compared to the knowledge and experience of mechanical ventilation.

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ObjectiveObjective




KnowledgeKnowledge






CostsCosts

FutureFuture


DesignDesign



More...More...

Simple, energy efficient, low cost natural ventilation system concepts for new and refurbished office buildings have to be developed.

Standards and guidelines must be developed so that there is a more favourable technical and legal framework for naturally ventilated office buildings.

Simple design tools: diagrams or easy - to - use computer programmes have to be developed.

Components and control systems for natural ventilation have to be improved.

General knowledge on natural ventilation has to be improved.

Simple, energy efficient, low cost natural ventilation system concepts for new and refurbished office buildings have to be developed.

Standards and guidelines must be developed so that there is a more favourable technical and legal framework for naturally ventilated office buildings.

Simple design tools: diagrams or easy - to - use computer programmes have to be developed.

Components and control systems for natural ventilation have to be improved.

General knowledge on natural ventilation has to be improved.

Conclusions &Conclusions & RecommendationsRecommendations

More information...More information...

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ObjectiveObjective




KnowledgeKnowledge






CostsCosts

FutureFuture


DesignDesign



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The European barrier report and the different national barrier reports (pdf-files) can be found on the CD-rom in the directory /Reports/Barriers/…

The European barrier report and the different national barrier reports (pdf-files) can be found on the CD-rom in the directory /Reports/Barriers/…

You can read and print pdf-files with the Acrobat® Reader ®3.0. Program. This program is free.

Download it from the Acrobat web site: www.adobe.com OR run the installation file ar32e301(1).exe in the directory \Installation

You can read and print pdf-files with the Acrobat® Reader ®3.0. Program. This program is free.

Download it from the Acrobat web site: www.adobe.com OR run the installation file ar32e301(1).exe in the directory \Installation

work package 1 perceived barriers to natural ventilation design of office buildings the objective of...

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