dcv flakt woods 2005

8/4/2019 DCV Flakt Woods 2005

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Demand Controlled Ventilation Saving energy, improving economy and protecting

the environment with Flkt Woods Group

Saving Energy,Economy and

Environment with

Flkt Woods.


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Introduction

In fact, approximately 40 percent of all the

energy consumed in the European Union

is used for buildings where ventilation

and air conditioning are major contributors.

As a consequence, and with the objective

to reduce the CO2

emissions with 20 percent

until year 2010 (compared with 1996 levels),

the Commission of the European Union have

issued the Energy Performance in Buildings

Directive (2002/91/EC). The directive is very

clear on the fact that energy savings in buil-

dings should not negatively affect the indoor

climate conditions.

Today, most people spend over 90 percent

o their time indoors e.g. at home, in

schools, at hospitals and oces. Breathing

resh indoor air is vital or our health,

perormance and weel being, and couldin act be considered as a basic human

right (1). However, we also know that

providing the necessary amount o resh

air to create a comortable and healthy

indoor climate consumes energy in terms

o electrical an power as well as cooling-

and heating energy. Energy that, when

produced also has a negative impact on

our environment and contributes to the

CO2-emissions to our atmosphere.


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Article 1

Objective

The objective of this Directive is to promote

the improvement of the energy performance

of buildings within the Community, takinginto account outdoor climatic and local

conditions, as well as indoor climate require-

ments and cost-effectiveness.

Article 4

Setting of energy performance

requirements

1. Member States shall take the necessary

measures to ensure that minimum energy

performance requirements for buildings

are set, based on the methodology referredto in Article 3. When setting requirements,

Member States may differentiate between

new and existing buildings and different

categories of buildings. These requirements

shall take account of general indoor climate

conditions, in order to avoid possible nega-

tive effects such as inadequate ventilation, as

well as local conditions and the designated

function and the age of the building. These

requirements shall be reviewed at regular

intervals which should not be longer than

ve years and, if necessary, updated in order

to reect technical progress in the building

sector. Source: EPBD 2002/91/EC

The indoor air directly affects people in all

stages of life. Childrens performance and

learning capabilities in classrooms, patients

recovery from illness when in hospitals,

peoples productivity and quality of workwhen in ofces are all examples where in-

ternational research have shown that indoor

air quality (IAQ) has a critical impact on the

outcome. In recent years, research has also

shown a relation between inadequate venti-

lation and absence due to sickness emphasi-

zing the importance of providing a healthy

indoor air climate.

The expression indoor air quality has

different meanings depending on context.

In this text, the following aspects of AirQuality are considered:

Physical factors such as temperature

and humidity.

Mechanical factors such as air velocity

and ventilation rate.

Human bioefuents (e.g, odours).

So, is a healthy indoor air climate

contradictory to a high level of energy

performance in a building?

No, the solution is Flkt Woods Groups

ventilation strategy based on Demand

Controlled Ventilation!


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Saving Energy and Protectingthe Environment with

Demand Controlled Ventilation

The main objective of a Demand Con-

trolled Ventilation system is to create

a high level of indoor air quality and

at the same time avoid unneccessary ventila-

tion and thereby to save energy.

Experience and eld studies have shown

that the level of CO2

in a room is a reliable

indicator of the air quality and ventilation

rate, and could therefore be used as the

determing parameter in Demand Control-

led Ventilation systems. People are the mainsource of CO

2in a building, if the number of

people in a room are doubled, the CO2

level

will also double. If one, or a few people leave

a room, the level of CO2

will proportionally

decrease.

A high level of CO2

in a rooom (>1000ppm)

indicates that the ventilation rate is insuf-

cient to obtain an adequate indoor quality.

Consequently a low level of CO2

(


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that are subject to large variations or inter-

mittent occupancy, but also rooms with static

occupancy patterns will benet from the ade-

quate ventilation provided with this concept.

from Demand Controlled Ventilation would

be 45-65 %.

In general, Demand Controlled Ventilation

systems are more advantageous in rooms

M

PO1

M

PO2

M

PO3

M

PO4

M

PO5

M

PO6

M

PO7

M

PO8

MPOAv

UD1

UD2

UD3

UD4

UD5

UD6

UD7

UDAv

IOAv

Totav(DennisJohansson2005)

80Occupancy rate / %

70

60

50

40

30

20

10

0

Occupancy rates for different spaces in three different buildings

Example 2

Difference in occupancy between all-time and daytime

Occupancy all-time


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Improving Economy withDemand Controlled Ventilation

Astudy published 2007 by Middlesex

University (3) shows the correlation

between levels of CO2 and wellbeing of occupants. The most important n-

dings from this study was the fact that when

levels of CO2

rise, the health complaints,

tiredness and lack of concentration also rise.

With CO2

levels above 1500ppm, 79 % of the

occupants reported feeling tired, and above

2000ppm 65 % of the occupants reported

having no level of concentration.

Even if it is difcult to set absolute gures

on the economical impact, the conclusion is

undoubtedly that poor indoor air qualtitywill have impacy costs through sick leaves

and decerased productivity and quality.

Depending on how a building is used, the

negative effects such as tiredness might

even involve critical risks e.g. in surgical

rooms, nuclear- or military control rooms etc.Unsatised tenants could also lead to

increased costs for a building owner in

terms of additional administration, bad-will

and ultimately loss of income if the tenants

decide to leave the buidling because of ina-

dequate indoor climate conditions.

Since CO2

levels in a room can be consi-

dered proportional to the ventilation rate, it

is also interesting to study the relationship

between ventilation rates and sick leaves.

Example 4 shows the compiled results ofseveral studies and suggests that sick leaves

will decrease when the ventilation rate

increases.

Example 3 & 4

Indoor air quality has nancial impact in the areas o peoples

well-being and thereby costs or sick leaves and health care.

1,0

Illnessorsickleaveprevalencerelative

to

prevalencewithnoventilation

Ventilation rate (h -1) air changes per hour

0,8

0,6

0,4

0,2

0

0 1 2 3 4

X

,

(Fisketal.2003)

, ,

, ,

,

549

30Count of Level of tiredness during AM occupancy of room

25

20

15

10

5

0

612

614

634

706

728

749

753

783

853

881

884

887

892

914

972

973

985

1039

(blank)

(Julie

J

Bennet2007)

The correlation between CO2

(ppm) leveland perceived tiredness Relative sick-leave as a function of ventilation rate

,

Drinka (1996), illness in nursing home

Brundage (1988), illness in barracks, all years

Particle concentration model

Brundage (1988), illness in barracks, 1983 data

Milton (2000), sick leave in offices

X

Alert and Awake

Average

No Level

Tired, ocassional Yarning

Very Tired

(blank)

4.

3.


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(1) Under the principle of human right to health, everyone

has the right to breathe healthy indoor air.EUR/00/5020494. World Health Organization

(2) Modelling life cycle cost for indoor climate systems

Report TVBH-1014 Lund 2005. Building Physics LTH.

Dennis Johansson

(3) Carbon Dioxide and IAQ Correlation, Julie J Bennet,

M00029823. Middlesex University

Bjarne W. Olsen (4), Indoor Environment Health,

Comfort and Productivity, Clima 2005 Lausanne, 8th

REHVA World Congress, Switzerland, Oct. 9-12, 2005.

Olli Seppanen and William Fisk (5), A Method to Esti-

mate The Cost Effectiveness of Indoor Environments in

Ofce Work, Clima 2005 Lausanne, 8th REHVA World

Congress, Switzerland, Oct. 9-12, 2005

Alan Hedge (6), Linking Environmental Conditions to

Productivity, Eastern Ergonomics Conference & Exposi-

tion, New York, June 2004.

A

study by Bjarne Olsen from Interna-

tional Center for Indoor Environ-

ment and Energy (ICIEE) in Den-mark, indicated that improved thermal com-

fort, reduction in indoor pollutants, and

enhanced ventilation rates and effectiveness

can increase productivity by 5 to 10 percent.

Conversely, the research also indicates that a

10 percent decrease in tenant satisfaction with

IAQ results in a 1 percent drop in productivity

In Finland, researcher Olli Seppanen,

from the Helsinki University of Technology,

developed a conceptual model to estimate

cost effectiveness based on improved indoorenvironment. The model shows a decrease

in performance by 2 percent for each degree

increase of space temperature between 25 de-

grees C and 32 degrees C. Optimal produc-

tivity performance was found to occur when

the space temperature was 22 degrees C.

In a study conducted by Allan Hedge of

Cornell University, low temperatures in

work space also have a negative impact on

productivity. His ndings show that chilly

workers not only make more errors, but

cooler space temperature could increase the

hourly labor cost by 10 percent.

Flkt Woods conclusion from these nd-

ings is that investing in a demand controlled

ventilations system with individual tempe-

rature settings in every room will not only

improve peoples well being and performan-

ce, but also reduce costs for sick leaves.

Indoor climate conditions, and itsimpact on human productivity

Human perormance is highly aected by the thermal

conditions and perceived level o comort.

References


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FWG-DCVBrochure-EN-200805-869

9Copyright2008FlktWoodsGroup

CondesignCommun

icationsAB+4636308380

Flkt Woods Group SA

18, avenue Louis Casa, CH-1209 Geneva, Switzerland

Tel. +41 22 309 3800

email [email protected] www.faktwoods.com

See global website or international sales oces www.faktwoods.com

We Bring Air to Life

FlktWoods is a global

leader in air management.

We specialise in the design

and manuacture o a wide

range o air climate and air

movement solutions. And

our collective experience

is unrivalled.

Our constant aim is to

provide systems that

precisely deliver required

unction and perormance,

as well as maximise

energy eciency.

Air Handling Units (AHUs)

Modular, compact and small AHU

units. Designed to ensure optimisa-

tion o indoor air quality, operational

perormance and service lie.

Air Terminal Devices and Ducts

Supply and exhaust diusers and

valves or installation onwalls, ceilingor oor are all included in our large

range and ft all types o applications.

Chilled Beams

Active induction beams or ventilation,

cooling and heating, and passive

convection beams or cooling. For

suspended or ush-mounted ceiling

installation and multi-service confg-

uration. With unique Comort Control

and Flow Pattern Control eatures.

Residential ventilation

A complete range o products or

residential ventilation. Consists o

ventilation units, exhaust air ans and

cooker hoods designed to optimise

indoor comort and save energy.

Energy recovery

Dessicant-based product and systems

that recover energy, increase ventilation

and control humidity.

Solutions for all your air climate and air movement needsFlktWoods is providing solutions or ventilation and air climate or buildings as

well as an solutions or Industry and Inrastructure.

Fans

Advanced axial, centriugal and

boxed ans or general and specialist

applications. Comprehensive range

including high temperature and ATEX

compliant options. Engineered or

energy efciency and minimised lie

cycle cost.

Chillers

Air-cooled and water-cooled chillers

with cooling capacity up to 1800kW.

Designed to minimised annual energy

consumption in all types o buildings.

Controls and drives

Variable speed drives and control

systems, all tested to ensure total

compatibility with our products.

Specialist team can advise on energy

saving and overall system integration.

Acoustical products

A complete line o sound attenuating

products, including rectangular and

round silencers. Media Free silencers,

custom silencers and acoustic

enclosure panels.

dcv flakt woods 2005

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