Insight in the Relation Between the Objective and Subjective Office Environment

8/3/2019 Insight in the Relation Between the Objective and Subjective Office Environment

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Technische Universiteit Eindhoven

Public Health Engineering For Built Environment

Insight In The Relation Between The ObjectiveAnd Subjective Office Environment

7Y900 Health & ComfortTercan , M.E.0629316

2007-Netherlands


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Table of Contents

Abstract

1. Introduction

2. Methodology

3. Results

3.1. Indoor Air Quality

3.2. Indoor Contaminants

3.3 Cleaning and Maintenance

3.4.Contaminant Source Control

3.5.Communication

3.6.Air Delivery Systems

3.7. Outdoor Air Supply Rate

3.8 .What is meant by thermal comfort?

3.9. What temperature should an office be?

3.10. What humidity level and air velocity should an office be?

3.11.Are there any standards on office temperatures?

3.12 What temperature is 'right' for various activities?

3.13 Why Satisfaction is Important

4. Discussions and Conclusions

5. References

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Abstract

The office environment is a combination of lighting, temperature, humidity and air quality. The office can be a healthy and comfortable place to work if the correctcombination of some elements is maintained like temperature,air conditioning,humidity etc The changing need for office property is being influencedheavily by the universal adoption of information and communications technology:

the vast array of mains and signal cables needs to be managed extra heat from the equipment needs to be controlled or removed new health and safety risks include electrical hazards, sitting positions,

eyestrain, lack of breaks and RSI information security needs to be considered amongst other security needs constantly changing businesses and processes demand flexible

accommodation.

Older buildings (and older furniture) are increasingly difficult to use effectively, andcosts of adaptation are being driven higher and higher. Organisations are seeking toescape from long leases on older buildings, either moving into newly built offices or entering into agreements to strip and refurbish, or in the extreme demolish andrebuild

As a consequence there has been an increase in demand for modern, flexible spaceon short-term leases, fuelling the success of the business centre sector. The very

best modern buildings incorporate zoned temperature and air quality control, naturallighting and good sound insulation. Unfortunately this all comes at a price that manyemployers are not prepared to pay. Most people end up working in officeenvironments that are sub-standard in some way.

After considering these results we realized that existing risks of the office spaecesin the modern business world are unavoidable.Continiously increasing problems alsoattracts both employees and emplyoers. While employees were gettingunproductiveness employers were having decreasing in their profits by this way.Itsclear that offices that design suitable for their aims and usage are necessary for every society.

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1.Introduction

Over the lifespan of a typical office building, it is estimated that 82% of all costsare those associated with office employees (mainly salaries and benefits), with theremaining cost being for the construction, maintenance and operation of the building(Brill, Weidemann & BOSTI Associates, 2001). It is also estimated that almost half of the European population is employed in office buildings (Giuliano, 1982; Christie,1985) and similar estimations have been made in relation to employees fromindustrialised nations in general (Bloom, 1986). As e very day, people have to work in a physical environment that affects their ability and desire to work (Goodrich,1982; p.355), and given the proportionally small cost of changing the physical officespace, it makes considerable sense to ensure that offices are designed to facilitatethe comfort and satisfaction of Office occupants.

The concept of open-plan office design evolved from burolandschaft , more

commonly known as office landscaping, a design movement that developed inGermany in the 1960s (Hedge, 1986; Burgess, Lai, Eisner & Taylor, 1989). Althoughvarying in form, this type of office design is characterised by modular furniture andmoveable partitions which partially screen office occupants from co-workersoccupying the same office space. This is in contrast to the conventional office designin which full height internal walls and doors provide separate, private office spaces.The proposed benefits of the open-plan office have been summarised bynumerous researchers (eg. Oldham & Brass, 1979; Sundstrom, Herbert and Brown,1982; Hedge, 1982; 1986; Cangelosi & Lemoine, 1988; Burgess et al, 1989;Jackson, Klein & Wogalter, 1997). In brief, the open-plan office is argued to bebeneficial in providing flexibility which organisations can utilise in response to

changes in organisational size and structure. Such designs also allow higher occupant density, thereby providing space and cost savings. Finally, advocates of theopen-plan office claim that these designs enhance communication betweenoccupants, which in turn promotes morale and organisational effectiveness. Thesepotential benefits are still persuasive in the modern office context and are reflected inthe continued popularity of open-plan office designs.However, despite enthusiastic support for open-plan offices, research suggestssome problems associated with this type of office design. The most commonly stateddisadvantage of open-plan offices is their lack of visual and acoustical privacy,coupled with an increase in distractions and interruptions ,for example, found thatemployees working in an open-plan computer office often reported being annoyed bydistracting sounds such as conversation, computer and printer beeping, the arrivaland departure of other people, keyboard typing and ventilation systems.

A number of searchs have demonstrated a lack of privacy in open-plan ascompared to conventional enclosed offices (eg. Brookes, 1972; 1978; Brookes &Kaplan, 1972; Sundstrom, Burt & Kamp, 1980; Hedge, 1982; Sundstrom, Herbert etal, 1982; Zalesny & Farace, 1987; Block & Stokes, 1989). Sundstrom, Herbert et al(1982) for example, found a decrease in satisfaction with privacy after employeesmoved from closed to open offices. Similarly, Carlopio & Gardner found thatemployees working in enclosed offices reported more communication privacy thandid those working in either open-plan or completely open office environments. Boyce(1974) noted that lack of privacy remained a major complaint one year after movingfrom closed to open offices.

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Acoustical privacy appears to be a particular problem for open-plan offices, andSundstrom, Town, Rice, Osborn & Brill (1994), for example, found that phonesringing, face-to-face conversations and phone conversations were the most

distracting noises for open-plan office occupants. Noise may be a more intrusivefactor than other ambient conditions (Jackson et al, 1997) and speech in particular has been shown to be distracting, especially when employees are engaged incomplex processing tasks (eg. Young & Berry, 1979; Jackson et al, 1997).

Privacy and distractions are important considerations as they affect employeesability to concentrate on quiet, focussed work, an activity in which office occupantsspend an estimated 48-64% of their time at work (Brill et al, 2001). Speech and officenoise can disrupt performance on some and perceived privacy and distractions havealso been shown to be related to environmental and job satisfaction

In addition to privacy considerations, research suggests that the proposedcommunication benefits arising from open-plan office designs are not alwaysrealised. One of the purposes behind open-plan environments is that the layout is

planned so that people who work together are near each other for efficient communication (Sundstrom, Herbert et al, 1982; p.380). Researchers have alsoargued that increased opportunities for communication facilitate the formation of social relationships, which in turn affect employee morale and satisfaction . However, although Allen & Gerstberger (1973) reported greater ease of communication after employees moved from closed to open office environments,other research has suggested that open-plan offices negatively influencecommunication (eg. Oldham & Brass, 1979). In Becker, Gield, Gaylin & Sayers(1983) study, for example, faculty staff and students at a community college reporteddifficulties in interacting with each other effectively when staff members were basedin open-plan as compared to closed offices.Some research has also suggested that employees may experience less favourableambient conditions in open-plan offices. Open-plan office occupants in Hedges(1982) study reported dissatisfaction with ambient conditions, particularly thoserelating to air quality and thermal comfort. In a telephone survey conducted byWoods, Drewry & Morey (1987), employees working in open-plan offices were 1.5times more likely to report poor air quality and to believe this negatively affected their

productivity as compared to employees in closed offices. Such problems are likely tobe related, at least in part, to employees inability to control ambient conditions and tothe variability of conditions within the open-plan work space. Furthermore, Hedge(1982) provides anecdotal evidence that, because of a lack of storage space in open-plan cubicles, occupants stored items on ventilation diffusers, thereby restrictingairflow.However, despite the potential problems that have been associated with open-planoffices, it seems likely that this type of office design will remain popular in futureyears.Thus, it is important to determine whether there are design characteristics that mayminimise the potential detriments to occupant satisfaction. Previous research has

suggested that workstation density and enclosure are two factors that could influenceoccupant reactions to open-plan office environments.

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Workstation density can be measured in terms of the number of occupants sharingan open-plan office, the distance from one occupant to another, the area of eachworkstation or the area of the floorplate per person. Although Szilagyi & Holland(1980) found that increased density lead to improved friendship opportunities,

information exchange and work satisfaction, the majority of research concerningdensity has indicated adverse occupant reactions as density . Increased workstation area, for example, has been associated with increasedenvironmental satisfaction and with perceived distractions (ONeill, 1994). Similarly,Oldham (1988) found that employees moving from an open office to a similar, butlower density, open Office experienced greater task privacy, communication privacyand environmental satisfaction, and reduced perceived crowding. In addition,occupants working in more crowded work areas were more likely to be dissatisfiedwith air quality (Woods et al, 1987). Workstation enclosure can be measured by thenumber of partitions surrounding a workstation or the height of those partitions. Ingeneral, studies show that the number of enclosed sides is positively related tooccupant perceptions of privacy and environmental and job satisfaction.However, although studies comparing offices with full height walls, partitions and nopartitions indicate greater privacy, communication and satisfaction as enclosureheight increases (eg. Sundstrom, Herbert et al, 1982; Oldham, 1988), few researchshave compared the more subtle effects of open-plan office partitions of differentheights (ONeill, 1994). Of those researchs which have been undertaken, ONeill &Carayon (1993) reported that average partition height was positively related toperceived privacy, and Brill et al (1984) found that partition height was positivelyrelated to ratings of communication, privacy and job performance.ONeill (1994), by contrast, did not find partition height to influence communication,distractions, privacy or satisfaction. In addition to these occupant reactions, ONeill(1992; p.891) notes that the degree of enclosure may influence the circulation of air within the work space and to some extent the ability to control the thermal environment (such as shutting a door to reduce drafts). In his own comparison studyof open, openplan and enclosed offices, this researcher found that enclosurepredicted satisfaction with temperature, although it was not significantly related tosatisfaction with air quality.

In addition to the workstations characteristics observate before, we also examinedthe influence of having an external window in the workstation. Access to a window is

clearly preferred by most people Office occupants express a preferencefor natural rather than artificial light and in addition to being a source of illumination, windows provide a view to the outside world .The accessibility of a view,particularly one of nature has been suggested as an important buffer to occupationalstress and is also related to occupant satisfaction.Open-plan office environments offer the potential to improve daylight penetration, butlittle work has been conducted to investigate the relationship between windows andoccupant satisfaction in such contexts.

In the current research, I aimed to examine the relationship betweenworkstation characteristics (workstation area, Windows etc) on environmental

satisfaction measures (satisfaction with privacy, ventilation andlighting, and overall environmental satisfaction).

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2.Methodology

For my assignment I chose the Vertigo building in TU/e campus .It has reallyinteresting past with his renovation in the campus.Building has too many differentoffice types and working areas then it makes the building more attractive fromvarious ways.And also atriums and fully closed areas at the ground levels areimportant to research on it.

Eindhoven Universitys Bouwkunde Faculty has a new building .With radicalrenovation of the old chemistry building.The completion of the Architecture ,Buildingand Planning facultys new premises is for several reasons a milestone in the historyof the TU/e .The event marks the begining of the end of the idea that informed the oldcampus set-up which envisaged technology education as lofty,but also rather unworldly activities.The fact is that the new building dubbed Vertigo following a call

to come up with a name is the first major contribution to a new masterplan for theuniversity which is intended to convey the social position of applied scienceeducation.As such the milestone is also an interim report and a harbinger of yet morechanges to come in.

.Like small working places,in first design the dubious decision had been takento insert mezzanine floors at the some point in the 5.1metre high spaces so as to beable to stack the offices,when in fact the space is inadequate for this.Next they had toheed the call for still more offices to be fitted into design so that as well as beingawfully low.

Pic.1 Vertigo 7.08 Typical Office Pic.2 Vertigo 7 th floor with two narrow floor around the atrium

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The former chemistry building containe a lot of big laborotories.It was thesethat accounted for the exceptional height of the spaces and depth of the floors.After determining main problems at the selected floors and selected working areasand contacting by facility manager study will insight the in the characteristics of thebuilding by using the HOPE checklist. After want all emplyoyees to completeHOPE questions they are gonna be tabled by graphs and other presentationways.Also combination of CO 2 lighting, temperature, humidity and air quality isimportant for this research.

1. What Information Do I Gather?

After made a contact with a facility manager I chose the 7th floor to work on it.Before starting to work at the interior of the building I determine other issues. Whereis the building situated? Are there any nearby potential sources of outdoor air pollution that might influence the indoor environment like Direct access frombasement or roof car park ,busy road,power plant for the building Because theseproblems also couse too many problems for workers in the building.As we knownoise and air pollution problems cause chronic stres and too many people dontunderstand that what is the reason about.

Some of the other important questions asked from Hope list ;

Total treated floor area

Total number of occupants in buildingType of glazing generally in the buildingHas there been any major water leakage or flooding in the last year?Is there a suspended ceiling?If in a radon-affected area, is there proper construction of foundation and ventilation(control of pressure difference), or other measures to control ingress of radon?

2. How Do I Analyze the Information that I Gather?

The nature of my question determines the method of analysis

- Descriptive questions call for descriptive methods- Correlational questions call for me to make correlations

How modifications and materials work with each other in the same time.if therewill be a problem with something is it possibel to change it with another one that wontcause problems for human life in the building.If there will be noise problems about exterior sources how will they block it whilestoring everything not damaged.?

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By collecting datas with given schedules and by put them to the graphs andtables it makes everything more clear and readeble. HOPE lists and other scheduleswere prepared by specialist for Works like this.By using this schedules we cananswer usual questions ,issues in our work are.

The graph should show enough data points over the range considered to

obtain the complete picture. In theobservatins I never answer questions such as,How many data points should I take? because I believe that everyone should beable to decide for themselves when there is enough data. Clearly two points are notenough for most undergraduate experiments, a hundred is time consuming andunnecessary.

3.Results (Data collection and presented in tables / graphs, and text)

Vertigos open-plan office has been popular among design professionals since thelate 1960's. This office design tends to produce higher occupant density than istypically found in traditional enclosed offices, a factor that has the potential toinfluence environmental satisfaction.

Many of the causes of poor indoor air quality and thermal conditions are similar for alltypes of offices at the floors of the building, ( Allen & Gerstberger 1973 ) However, open-plan offices tend to be more densely populated than individual enclosed offices, asituation which can influence the amount of heat and contaminants produced in thespace. It is important, therefore, that these factors be taken into account whenapplying standards and recommendations to the design of open-plan offices.

The results includes ideas that can be used to increase occupant satisfaction andcomfort, and reduce physical symptoms. The prevention of more serious healthconditions (e.g., asthma, cancer, hyper-sensitivity) is not addressed. If there isreason to believe that serious health concerns are related to the air quality or thermalconditions in the office, an investigation by medical and indoor environmentspecialists should be carried out.

3.1.Indoor Air Quality

To achieve good IAQ, many factors must be considered in the offices . These includethe type and amount of contaminants in the space, the quality and quantity of theoutdoor air supply, the movement of air and contaminants within the space, and thecleanliness of the office space and ventilation system.

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3.2.Indoor Contaminants

Contaminants in the office space can arise from many sources. For example, outdoor contaminants from vehicles and factories,laborotories, such as carbon monoxide andsulphur dioxide, can enter the building through the ventilation system, doorways or

infiltration through walls. Building materials and office furnishings contain chemicals,particularly volatile organic compounds (VOCs), that are continuously being releasedinto the indoor air. Office equipment, such as printers and photocopiers, can createozone, and also emit VOCs. Dust and moisture can accumulate in ventilationsystems and office spaces, providing a habitat for microbial contaminants.

In the vertigo (7 th floor) Office occupants themselves can also be a source of contaminants, which can include the by-products of breathing and perspiring,personal hygiene products (such as perfume and deodorants), and dust and animaldander carried into work on clothing. All of the above contaminants can make the air feel dusty and stale, produce unpleasant odours, and lead to occupant dissatisfactionand discomfort.

3.3Cleaning and Maintenance

Contaminants can accumulate in the office space and in the ventilation system itself.Regular and thorough cleaning of the space and the ventilation system equipmentreduces the accumulation of dust, VOCs and microbes, and also improves occupantsatisfaction and reduces physical symptoms. 2 However, because some cleaningprocesses temporarily distribute dust into the air, and many cleaning productscontain VOCs themselves, these activities should be undertaken when the offices arenot occupied.

3.4.Contaminant Source Control

The best way to improve IAQ is to prevent contaminants from entering the officespace in the first place. For example, careful selection of materials and products canreduce the quantity of VOCs emitted, particularly when new materials are introducedinto the office space. Figure 2 provides one example of how VOC concentrations canbe reduced when low-VOC-emitting products rather than typical products are

chosen.8

High-efficiency air filters should be used in the ventilation system, to prevent outdoor contaminants from entering the office space.

3.5.Communication

Indoor air quality can be a sensitive issue for occupants, managers and buildingoperators. One way to avoid conflicts is to develop a clear and responsive complaintsprocedure. This way, concerns can be promptly addressed, clear feedback given,and IAQ problems solved quickly.

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3.6.Air Delivery Systems

Air supply diffusers and return air grilles should be positioned and operated so thatair is evenly delivered to all parts of the office space, and contaminants effectivelyremoved or diluted. Air delivery systems used in Europe include traditional (mixing),

displacement and personal (local) systems.

Most European open-plan offices use a traditional system. As long as this type of system is properly designed and operated, it can produce good IAQ. Researchersfound that workstation size, panel height, and supply diffuser location had little effecton how well a traditional system controlled contaminant concentration in an open-plan office space However, occupants in workstations with high panels tend to beless satisfied with ventilation. 2 This is likely to be a psychological effect rather than afunction of the physical environment that is, there is an occupant perception thathigh panels impede acceptable airflow. For this reason, panels higher than 1.68 m(66") should be avoided.

3.7.Outdoor Air Supply Rate

Office spaces need to be ventilated with sufficient outdoor air to dilute contaminantsand provide occupants with oxygen for breathing. For many years, Standardsrecommended a minimum outdoor air supply rate of 10 litres per second per person(L/s.p), but recently this rate was reduced to 8.5 L/s.p. 4 This reduction can lead toenergy savings, but the effect on occupants is unclear because research to comparethese two rates has yet to be conducted. However, research suggests that outdoor air supply rates below 10 L/s.p may lead to occupant discomfort and dissatisfaction,increased physical symptoms, absenteeism, and reduced task performance.Recommendations of 8.5 L/s.p should be treated as an absolute minimum outdoor air supply rate; a rate of 10 L/s.p is preferable for IAQ purposes.

Achieving adequate ventilation in the occupied space also depends on appropriateoperation of the ventilation system. Special steps should be taken where possible,such as increasing the ventilation rate or isolating the area when renovating officespaces or installing new materials and furnishings, as materials typically emit themost VOCs when new. 6

As outdoor air supply rates are determined on a per person basis, it is important to

establish an appropriate outdoor air supply based on the occupancy of the open-planoffice, and to revise this appropriately following any changes in occupant density.

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3.10.What humidity level and air velocity should an office be?

When relative humidity is kept at about 50%, office workers have fewer respiratoryproblems (specifically in the winter) and generally feel better. Higher humidity makesthe office feel "stuffy". More important, it can contribute to the development of

bacterial and fungal growth (especially in sealed buildings).

Humidity lower then 50% causes discomfort by drying out the mucous membranes,contributing to skin rashes. Dry conditions cause electrostatic charge on both officeequipment and their users.

Air velocities below 0.25 metres/second (or about 50 feet/minute) does not createany significant distraction even in tasks requiring sustained attention.

3.11.Are there any standards on office temperatures?

The CSA Standard CAN/CSA Z412-00 - "Office Ergonomics" gives acceptableranges of temperature and relative humidity for offices in the world. Therecommended temperature ranges have been found to meet the needs of at least80% of individuals. Some people may will feel uncomfortable even if these values aremet. Additional measures may be required.

Table 1Measured Temperature / Humidity Ranges for Comfort in the Floor

Conditions Relative Humidity

Acceptable OperatingTemperatures

C F

Summer (light clothing) If 30%, thenIf 60%, then24.5 - 2823 - 25.5

76 - 8274 - 78

Winter (warm clothing) If 30%, thenIf 60%, then20.5 - 25.5

20 - 2469 - 7868 - 75

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Table 2 shows measured (and even acceptable) temperatures ranges for relativehumidity levels of 30% and 60%in the 7th floor

Table 2Examples of acceptable operative temperature ranges based on comfort zonediagrams

Conditions Acceptable operative temperatures

C F

Summer (clothing insulation = 0.5 clo)

Relative humidity 30% 24.5 - 28 76 - 82

Relative humidity 60% 23 - 25.5 74 - 78

Winter (clothing insulation = 1.0 clo)

Relative humidity 30% 20.5 - 25.5 69 - 78

Relative humidity 60% 20 - 24 68 - 75

3.12In general, what temperature is 'right' for various activities?

Table 3 summarizes some typical responses to various temperatures.

Table 3

Temperature

F C

78 25 Optimal for bathing, showering. Sleep is disturbed

75 24 People feel warm, lethargic and sleepy. Optimal for unclothedpeople.

72 22 Most comfortable year-round indoor temperature for sedentarypeople.

70 21 Optimum for performance of mental work.

64 18 Physically inactive people begin to shiver. Active people arecomfortable.

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4.Discussions and Conclusions

In the interior Vertigo has too many kinds of working space and it means thatthere is too many problems about and solutions about these office environments.Until quite recently ,it would have been quite out of the questions to create the kind of workspaces on these floors that are now to be found there: Dutch buildingregulations decreed that work spaces had to be close to the outer walls so as toprotect users from having to work in dark and airless places deep within abuilding.This was why all office buildings in Nederlands look the same and havemuch the same double-loaded corridor profile.In other parts of the world wherepeople were not so bothered about working under artificial light and in air conditionedspaces,other building types were able to evolve,such as skyscrapers with their deepspace .In the Nederlands it was only the widespread ntroduction of the computerswith their need for subdued light rather than a place at the window that bropughtabout a relaxation of this regulation.

Several other issues suggest that the relationship between outdoor ventilation ratesand occupant responses may be more complex than is sometimes considered. For example, as noted by Godish & Spengler (1996; p.140), The ability of general ventilation to reduce contaminant levels can be compromised by inadequate mixing of supply air in occupied spaces. Contaminant removal efficiency may differ between spaces or within a space, due toventilation strategies, air flow patterns and room characteristics (eg. Teijonsalo,Jaakkola & Seppanen, 1996; Haghighat, Zhang, & Shaw, 1996). Thus, reportedoutdoor ventilation rates may not adequately reflect the actual ventilation conditions

in some parts of a building or room.

In addition, the ability of outdoor ventilation rates to remove contaminants is relatedto the nature and sources of pollutants present in the building under study (Godish &Spengler, 1996; Seppanen et al, 1999). Thus, a given outdoor ventilation rate may besufficient to ensure favourable occupant responses in low polluting environments, butmay be insufficient in high pollution load conditions. Current European standards for outdoor ventilation rates in office spaces are set with the assumption that there areno unusual sources of pollution present in the building. Despite this fact, the reviewedstudies varied considerably in the information provided about pollution loads. Whilst itis acknowledged that a comprehensive analyses of building contaminants may betime consuming and costly, some indication of the presence of any unusual pollutionsources would be useful in interpreting results. This issue may be particularlyimportant where pollution loads are likely to vary between buildings or zones(Mendell, 1993).

A further consideration is the fact that pollutant concentrations are also affected bythe quality of the supply air. This is determined in part by recirculation rates, but willalso be affected by the pollutants present in outdoor air, the location of the outdoor air intake relative to outdoor pollution sources and the ability of ventilation systems tofilter out contaminants (Seppanen et al, 1999).

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The ventilation system itself may constitute a source of pollution, and has beenshown to be a source of VOCs (Molhave & Throsen, 1991) and a potential site for bacteria and fungi, particularly in ventilation systems which incorporate air-conditioning (Sverdrup & Nyman, 1990; Morey, 1988). As such, regular maintenanceand cleaning of ventilation systems has been argued to be important to occupant

responses (eg. Burge, Jones & Robertson, 1990; Bluyssen, 1993), and studiesinvestigating the impact of outdoor ventilation rates should determine the potential for ventilation system pollution to affect results. Wargocki et als (2000) study isparticularly useful in this respect, since this study was conducted using a ventilationsystem argued to minimise the confounding potential of pollution from this source.Overall, as Godish & Spengler (1996; p.142) noted,the relationship between building ventilation conditions and air quality is relatively complex. As such, the use of general ventilation to mitigate building-related healthcomplaints should be tempered by an understanding of the various factors than may limit its effectiveness and that it is not a generic solution to indoor air quality

problems.

In my opinion modifications in the building is the main problem for employees in thebuilding,Ventilation ,heating system ,water and heat insulations are one of the mainexcuse of the problems.By the way all modifications have material sources and thismaterials effects on human breathing system ,nervous system etc.In past years some building materials are forbidden for healtcare like asbestos.Itsimportant to know did they use any materials before these materials made forbidden..

This feeling is also echoed in an addendum to the latest ASHRAE ventilationstandard, which states that;compliance with the standard will not necessarily result in acceptable indoor air quality for a variety of reasons. The comfort and health effects of indoor environments are very complex and not fully understood. It is not possible at this timeto create a standard that will provide acceptable indoor air for all occupants under all circumstances. (ASHRAE 1999; p.1)

However, although outdoor ventilation rates should not be relied upon as the onlymechanism to ensure adequate indoor air quality, the current review does confirmthat outdoor ventilation rates do make an important contribution to occupantsatisfaction. Our review suggests that applying a minimum outdoor ventilation rate atthe current standards, is likely to avoid serious detriments to occupant satisfaction,

provided that this level of ventilation is achieved locally and maintained over time.As might be expected, occupants with workstations that incorporated a windowwere more satisfied with lighting. However, we also found that these occupants wereless satisfied with ventilation, as compared to occupants in windowless workstations.The windows in the study sample were sealed; therefore, this finding is probably theresult of temperature variations arising from increased draught during the winter andincreased heat gain during the summer.I found that those occupants with a lower minimum partition height were moresatisfied with overall environmental satisfaction. The mechanisms behind this findingare less obvious; however workstations containing at least one lower height partition

might provide occupants with an improved sense of space, and may also improve

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ambient conditions (through, for example, better air flow or access to overheadlighting).

However, although the above findings were statistically significant, I found thatthe overall amount of variance in occupant satisfaction that could be explained by

workstation characteristics was relatively small (between 4 and 14%). One reason for this may be the largely favourable workstation characteristics found in the literature.For example, although workstation area ranged from 12.5 to 30 m 2 , the averageworkstation area was 20m 2. Therefore, in many cases, workstation area might havebeen too large to influence occupant responses greatly. In addition, whilst minimumpartition height varied from 0 to 2.5m, the majority of workstations had a minimumpartition height of 2.3m, and this restricted range is likely to have influenced myresults. Previously researchs on open-plan offices has often compared open andclosed environments, in which the characteristics of spaces differ more dramatically

It is likely that the effects of workstation variations within open-plan environments aremore subtle and more difficult to detect. Such considerations suggest that future workshould attempt to include a wider ranges of workstation characteristics, either through the use of a greater number of different buildings or through examining theeffects of changes in workstation characteristics over time (as is currently planned for thepostrenovation phase of the COPE field study).An alternative argument is that different measures of workstation characteristicsmight better explain differences in occupant environmental satisfaction. For example,in previously studies(Boubekri & Haghighat, 1993) researchers have used alternativemeasures of enclosure, such as average partition height or number of partitions.Similarly, the effects of workstation area might differ from density measures that takeinto account the position of workstations relative to each other, such as the distancefrom one occupant to the next, the number of employees within a specified radius of the target occupant, or area on the floorplate per person. Workstation characteristicsnot featured in my current study, for example the amount of storage space or locationon the floorplate relative to exhaust outlets, might also be related to occupantenvironmental satisfaction. Future work could, therefore, benefit from the inclusion of alternative measures of workstation characteristics.

A number of researchers have highlighted the potentially complex relationshipsbetween the physical office environment, occupants perceptions of those

environments and their reactions towards them. This complexity is highlighted in astudy by ONeill & Carayon (1993). Here, perceived enclosure accounted for 43% of the variance in satisfaction with privacy, whereas physical enclosure (measured asworkstation area and average partition height) accounted for only 8%; suggestingthat perceptions of enclosure were formed from more than simply the physicalcharacteristics of workstations.It has been argued, for example, that occupantresponses to office environmentare influenced by personal and organisational sfactors. Job complexity has previously been related to occupant satisfaction, withoccupants preferring more privacy when completing more complex tasks (ie. Hedge,1982; Sundstrom, Town et al, 1982; Block & Stokes, 1989; Fried, Slowik, Ben-David& Tiegs, 2001). This is likely to be because complex tasks require more focused

concentration, and so more private environments provide a buffer against distractionsand interruptions. Related to job complexity, job level has also been associated with

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occupant satisfaction (eg. Johnson, 1970; Hedge, 1982; Carlopio & Gardner, 1992;1995). Here, managers are typically found to be more sensitive to privacy anddisturbances, primarily because higher level jobs are assumed to be more complexand demanding.

Other factors, such as organisational tenure, experience of alternative officeenvironments, abilities to screen out distracting stimuli, and personal needs for privacy, have also been associated with occupant satisfaction (eg. Hedge, 1982;Oldham, 1988; Block & Stokes, 1989; Jackson et al, 1997; Fried et al, 2001). Inaddition, as noted by both Sundstrom (1987) and Marans & Spreckelmeyer (1982),occupant responses are also likely to be affected by how an individuals ownworkstation compares to those of their co-workers, and to the workstation they feelthey deserve to have. characteristics and occupant environmental satisfaction mightalso interact with the relative importance that occupants place on environmentalfeatures. Sundstrom (1987), for example, argues for a weakest link approach, inwhich the aspect of the environment that the occupant is least satisfied with becomesthe most important in determining environmental satisfaction. In the current study, Ifound that occupants in larger workstations and occupants in windowed workstationstended to rate access to a window as more important than did occupants in smaller workstations and windowless workstations respectively. This latter finding is incontrast to previous research, which has suggested that occupants in windowlessworkstations tend to rate the importance of having a window higher than occupants inwindowed workstations (Boubekri & Haghighat, 1993). Thus, whilst others haveargued that occupants rate aspects of the environment as more important if they donot currently have them, our findings suggest that occupants might underplay theimportance of features they do not have (particularly if it is unlikely that they willobtain them in the future). Clearly, more work is needed to determine the role of occupants importance rankings, particularly in relating these ratings to occupantsatisfaction.

Finally, I note that little work has been undertaken on the mediating role of physical ambient conditions on the relationship between workstation characteristicsand occupant satisfaction. It can be argued that workstation characteristics affectambient conditions, such as illuminance, temperature and noise levels, which in turnaffect occupant satisfaction. As such, stronger relationships might be evidentbetween ambient conditions and occupant satisfaction than were found here for workstation characteristics. This notion may be particularly important if the same

workstation characteristic is positively related to one ambient condition but negativelyrelated to another ambient condition.Some work has been conducted on the relationship between workstationcharacteristics and ambient conditions. Bauman et al (1992), for example, conductedenvironmental chamber experiments and concluded that variations in partition heightproduced only small differences in overall thermal and ventilation performance.ODonnell & Nguyen (1990), by comparison, argue that partition height influences air velocity. Other work has suggested that partition height and the provision of a gap atthe bottom of the partition does not affect air distribution or mean age of air, but doesaffect contaminant removal efficiency (eg. Haghighat, Huo, Zhang & Shaw, 1996).Haghighat et al (1996) also noted that the workstation nearest to the return grill

tended to have the worst contaminant concentrations, because pollutants from other sources in the space were being drawn towards the return grill. Furthermore,

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Haghighat (1994) found that the layout of workstations in an open office spaceaffected airflow patterns, and couldtherefore influence contaminant removal. In relation to acoustical parameters,researchers have also noted the role of partition height and partition construction indetermining speech privacy (eg. Moreland, 1988).

There is a clear need for the extension of work of this kind, to link workstationcharacteristics, ambient conditions and occupant environmental satisfaction together.

In this study, I found significant, albeit small, relationships between workstationCharacteristics relation between the objective and subjective office environment andoccupant environmental satisfaction. These findings provide a promising base fromwhich to further explore these relationships. Potential directions for the future includeobtaining data on a broader variation of workstation characteristics (either fromadditional buildings or from the same buildings over time), examining alternativeworkstation measures, investigating the role of job category in more depth, relatingoccupant importance rankings to occupant satisfaction, and analysing therelationships between workstation characteristics,

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References

Allen, E. C., & Gerstberger, P. G. (1973). A field experiment to improvecommunications in a product engineering department: The nonterritorial office.Human Factors, 15(5), 487-498.

Banbury, S., & Berry, D. C. (1998). Disruption of office-related tasks by speech andoffice noise. British Journal of Psychology, 89, 499-517.

Bauman, F. S., Faulkner, P. E., Arens, E. A., Fisk, W. J., Johnston, L. P., McNeel, P.J., Pih, D., & Zhang,H. (1992). Air movement, ventilation, and comfort in a partitionedoffice space. ASHRAE Transactions: Symposia, 756-780.

Becker, F. D., Gield, B., Gaylin, K., & Sayer, S. (1983). Office design in a communitycollege: Effect on work and communication patterns. Environment and Behavior,

15(6), 699-726.

Block, L. K., & Stokes, G. S. (1989). Performance and satisfaction in private versusnonprivate work settings. Environment and Behavior, 21(3), 277-297.

Bloom, D. E. (1986). Women and work. American Demographics, 15, 25-30.

Boubekri, M., & Haghighat, F. (1993). Windows and environmental satisfaction: Asurvey study of an office building. Indoor Environment, 2, 164-172.

Boyce, P. R. (1974). Users assessments of a landscaped office. Journal of

Architectural Research, 3(3), 44- 62.

Brill, M., Margulis, Konar & BOSTI (1984). Using Office Design to IncreaseProductivity (Vol. 1). Buffalo, NY: Workplace Design and Productivity Inc.

Brill, M., Weidemann, S., & BOSTI Associates. (2001). Disproving widespread mythsabout workplace design. Jasper, IN: Kimball International.

Brookes, M. J. (1972). Office landscape: Does it work? Applied ergonomics, 3(4),224-236.

Brookes, M. J. (1978). Changes in employee attitudes and work practices in an officelandscape. In A.

Brookes & Kaplan, 1972; The office environment: Space planning and affectivebehavior pg 66,84,146

Burgess, Lai, Eisner & Taylor, 1989 Environmental Satisfaction in Open-PlanEnvironments: 2 ,pg350

Friedmann, C. Zimring & E. Zube (eds.), Environmental Design Evaluation (pp. 35-45). London: Plenum Press.

21


22/23

Brookes, M. J., & Kaplan, A. (1972). The office environment: Space planning andaffective behavior. Human Factors, 14, 373-391.

Burgess, M. A., Lai, J. C. S., Eisner, M., & Taylor, E. (1989). Speech privacy in open-plan offices post occupancy. Proceedings of the 25th Annual Conference of the

Ergonomics Society of Australia: Ergonomics, Technology, & Productivity, 26-29November (pp. 351-354). Fortutide Valley, Australia: Ergonomics Society of Australia.

Dean, L. M., Pugh, W. M., & Gunderson, E. K. E. (1975). Spatial and perceptualcomponents of crowding: Effects on health and satisfaction. Environment andBehavior, 7, 225-236.

Fried, Y., Slowik, L. H., Ben-David, H. A. & Tiegs, R. B. (2001). Exploring therelationship between workspace density and employee attitudinal reactions: Anintegrative model. Journal of Occupational and Organizational Psychology, 74, 359-372.

Giuliano, V. E. (1982). The mechanization of office work. Scientific American, 247(3),149-164.

Goodrich, R. (1982). Seven office evaluations: A review. Environment and Behavior,14(3), 353-378.

Marans, R. W., & Speckelmeyer, K. F. (1982). Evaluating open and conventionaloffice design. Environment and Behavior, 14(3), 333-351.

Markus, T. A. (1967). The function of windows: A reappraisal. Building Science, 2,97-121.

Mital, A., McGlothlin, J. D., & Faard, H. F. (1992). Noise in multiple-workstation open-plan computer rooms: Measurements and annoyance. Journal of Human Ergology,21, 69-82.

Oldham, G. R., & Rotchford, N. L. (1983). Relationships between officecharacteristics and employee reactions: A study of the physical environment.Administrative Science Quarterly, 28(4), 542-556.

Oldham & Brass, 1979; Sundstrom Desgnng Effectve Study Envronments pg114-115

O'Neill, M. J. (1992). Effects of workspace design and environmental control on officeworkers' perceptions of air quality. Proceedings Of The Human Factors Society, 36thAnnual Meeting, Atlanta GA. Part 2 (pp. 890-894). Santa Monica, CA: The HumanFactors Society.

O'Neill, M. J. (1994). Work space adjustability, storage, and enclosure as

22
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23/23

Sundstrom, Herbert et al, 1982; Prvacy In The Work Place: The Impact Of BuldngDesgn p.380Sundstrom, Herbert et al, 1982; Traditional versus Open Offices: A Comparison of Sociotechnical, Social Relations, and Symbolic Meaning Perspectives pg 85,93

Veitch, J. A, Farley, K. M. J., & Newsham, G. R. (2002). Environmental satisfaction inopen-plan environments: 1. Methods and scale validation (Internal Report No. IRC-IR-844). Ottawa, ON: National Research Council Canada, Institute for Research inConstruction.

Wells, B. W. P. (1965). Subjective responses to the lighting installation in a modernoffice building and their design implications. Building Science, 1, 57-68.

Woods, J. E., Drewry, G. M., & Morey, P. R. (1987). Office worker perceptions of indoor air quality effects on discomfort and performance. Proceedings of Indoor Air '87. The Fourth International Conference On Indoor Air Quality and Climate (pp. 464-468).

Young, H., & Berry, G. (1979). The impact of environment on the productivityYoung & Berry, 1979 Lifetime measurements of Environment pg 250

http://irc.nrc-cnrc.gc.ca ( Institue for Research in Construction )http://ww.ashrae.com
http://linkinghub.elsevier.com/retrieve/pii/S0272494498900810http://linkinghub.elsevier.com/retrieve/pii/S0272494498900810http://irc.nrc-cnrc.gc.ca/http://ww.ashrae.com/http://linkinghub.elsevier.com/retrieve/pii/S0272494498900810http://linkinghub.elsevier.com/retrieve/pii/S0272494498900810http://irc.nrc-cnrc.gc.ca/http://ww.ashrae.com/

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Insight in the Relation Between the Objective and Subjective Office Environment