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The psychological effects on man of air movement and the colour of his surroundings
Applied Ergonomics 1984, 15.2, 119-126
The psychological effects on man of air movement and the colour of his surroundings M.V. Jokl Faculty of Engineering, Technical University of Prague, Czechoslovakia
The psychological microclimate is a term which is used to describe the specific psychological effects of some environmental a.qents as well as the psychological effects of other factors of the physical environment (e g, colour of surroundings, etc). This paper considers air motion and colour schemes of space, defines their stress and strain factors, describes the psychological effects - post-strain, and the methodology of their investigation. It further sugqests the criteria and limiting and optimum values of the dynamic effect of air (permissible air velocities in interior and exterior environments) and the colour scheme of space (in accordance with the Tektronix standard). In conclusion the paper sums up the possibilities of optimisation of the 'psychological microclimate'.
Kevwords: Environment (working), air flow, colour schemes Introduction The psychological microclimate is affected by both specific environmental agents within the microclimate and other additional effects of the microclimate. All constituents of the microclimate can have a psychological effect. This includes hygro-thermal conditions (e g, dissatisfaction with heat or unsuitable heating conditions, inability to concentrate, fear of cold), odours (e g, pleasant and unpleasant odours, warning effect of odours) and the electroionic environment (which is believed to produce headaches which can have psychological effects such as aggression). Air motion, not as a bearer of heat or aerosols, but by its effect as a wind or draught, can also have an effect. In addition, the space with its three dimensions, plan, size and colour scheme, also man himself (Krivohlavy, 1973) as a component of the human environment of others, represents a further factor which can influence the psychological microclimate. A great role is also played by the accuracy of room construction (Stevens, 1976 - see Fig. 1). The lack of straightness of walls, level of floors or other surfaces, uneven flooring, gaps between panels, warped windows and doors and other defects of construction represent further significant factors which contribute to the psychological environment. The 'psychological microclimate' not only influences the physical condition of man in a certain microclimate but also affects the feelings of physical comfort or discomfort. For example, Stverak (1966) ascertained that during the exposure of the human organism to heat (globe temperatures of up to 50°C) the feeling of excessive heat strain can be accompanied by a heavy psychological experience (e g, as when reading an exciting mystery story) (Fig. 2). The
psychological microclimate also contributes to the creation of the feeling of human comfort. For example, when considering the hygro-thermal environment, the optimum hygro-thermal condition may not be sufficient to create hygro-thermal comfort. Optimum psychological conditions are also required. NOTE: The term 'psychological microclimate' is not used in the same sense as for example 'hygro-thermal microclimate', which affects man by heat and humidity. Psychological microclimate is used in the sense of 'that which is affected by the microclimate' (i e, the psyche of man).
Psychological stress due to air motion and colour scheme of space Air motion In a hygro-thermal environment, air motion can cause cooling or warming effects due to heat transfer by convection. The air flow, however, can also produce unpleasant sensations independently of these effects, due to its dynamic effect (e g, by undesirable effects on clothing) (Fig. 3). It can, for example, cause upturning of umbrellas or disturb the leaves of a book one is reading, particularly in the vicinity of tall buildings (Penwarden, 1975). The dynamic effect of air is characterised by the: (a)
frequency, direction and speed of air flows.
(b)
configuration of the space in which the air flows occur (e g, there is often an interaction between the configuration of the ground and of architectural works)
0003-6870/84/02 0119-08 $03.00 O 1984 Butterworth & Co (Publishers) Ltd
Applied Ergonomics
dune 1984
119
Is it straight ?
Is it level ?
Is it vertical ?
Will it fit ?
Is it flat ? Accuracy in building
Fig. 1
(c)
configuration of the surfaces of the exposed subject (e g, his clothing) which, however, ranges among the factors of strain.
Frequency, direction and speed of air flow
Analysis of these factors reveals that they can be replaced with a single quantity - the mean air velocity (Penwarden, 1975). For outdoor environments these factors are recorded by the nearest meteorological station.
The level of accuracy of interior dimensions (Stevens, 1976)
of the tall building H, the so-called R H ratio. For tall buildings, its value amounts to 0.5 for the vortex flow, 1.0 for the corner streams and 1"2 for the concentrated throughflow. For low rise buildings it comes between 0-3 and 0.4. Thus a person walking from a sheltered region of low rise building may experience a fourfold increase of air velocity on entering a passageway beneath a tall building (Jokl, 1980).
Colour scheme of space
Configuration of space In external environments a dominant role is played by tall buildings, not only because of their height and location, but also with respect to their position in relation to other buildings and structures. In a space of interest, there are three principal regions of increased air velocity (Fig. 4). These are, the vortex flow, the corner streams and the concentrated through-flow. The vortex flow originates behind a low rise building, the concentrated through-flow and the corner streams are due to the congestion of stream lines around the tall building. These are due to the effect of passages and corners of the building and to the diversion of the air flow downwards, to the pedestrian level, as a result of which they are also a function of the height of the building. The absolute value of air velocity is replaced with the ratio of the air velocity at pedestrian level to the wind velocity at the top
120
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June 1984
The colour scheme of any component of environment can be characterised by the following quantities: hue, lightness and saturation. The difference among them is illustrated in Fig. 5 (Davis and Metrick, 1978). Colour of surface and colour of light
One of the factors contributing to psychological stress is the perceived colour of the surface or the light reflected from the surface, which is the result of an interaction of the colour of the surface and the colour of light incident on the surface. Material on the surface
Materials are characterised by their colour and this is accentuated by the surface texture.
r!
!/ P
I' I L
!ri
r I'
/' I ' i
( i' rL b r f~
t'J
,!
f
f L
iI I
example, an unusual eolour scheme may be perceived as being 'dirty' (actual or apparent). Psychological strain may motivate and even influence, in the long run, the psyche of man. It may also influence the physiological state of the human organism, which may manifest itself, for instance, in the endocrine system by direct strain on the stomach and on the production of adrenaline and other hormones which mobilise the whole organism (Selye, 1974). (Fig. 6). Psychological strain, produced by environmental components, is modulated by the psychological condition of man (Fig. 7), his physiological state, (e g, hunger (Rohles and Wilson, 1973)), his previous experience and his habits and customs. The dynamic effects of air motion can also produce psychological strain which depends upon the configuration of the surface of the exposed subject (e g, his clothing).
Configuration of the surface of the exposed subject Moving air affects an exposed subject by the force F which is determined by the relationship: p v~ F = A CD (S) 2 Where A
- projected area normal to the air stream (m=)
CD
- drag coefficient (ND)
p
- air density (kg/m 3)
v
- air velocity (m/s).
Since the variations of air density will not be significant in the majority of cases, the dynamic effect of air on the subject depends primarily on air velocity and on the drag coefficient of the subject and his projected area normal to the air stream. If the exposed subject is man, his projected area normal to the air stream can be determined from his total surface. Fig. 2
With the simultaneous effect of various microclimate components on the subject, the psychological microclimate should not be overlooked
Combination of colours
In multi-coloured surfaces the combination of colours play a role of importance which can be assessed with reference to: (a)
so-called complementary combinations (e g, the combination of yellow and blue).
(b)
saturated and non-saturated colours (e g, the combination of saturated blue and pastel blue).
(c)
colours of different lightness (e g, the combination of light blue and dark blue).
Factors of psychological strain If the components of an environment produce psychological effects on man then the perception of those components is more intense (by aperception, i e, due to experience, associations, evaluation, anticipation, etc), than that experienced by sensory perception alone. This involves very complicated and heavily subjective processes. For
Fig. 3
Psychological effect of streaming air
Applied Ergonomics
June 1984
121
~,~~ Three main areas of increased wind velocity around a tall building (Penwarden, 1975)
Fig. 4
According to Penwarden, Grigg and Rayment (1978), this projected area will be: (a) (b)
~Conres-reto
if facing the air stream: AF = 0.35ADu =0"0269 W0"425.H0725
(m 2)
if sideways to the air stream: A = 0"26ADu = 0.0200 W0"425j-/0"725
(m 2)
where total surface of a nude body (DuBois area),
ADu
-
IV
- weight of man (kg)
H
- height of man (m)
(m 2)
for males and females wearing trousers and a flapping coat. The aforementioned figures refer to the persons facing the air stream (sideways to the air stream) respectively, the average value for 331 persons being 1-16 (1.01) with the possible deviation of as much as 15% for various types of clothing. The drag coefficient for persons wearing trousers (1-18 and 1 "02 respectively) was 7 - 10% higher than the same coefficient for persons wearing skirts (1 "08 and 0.95 respectively). There were no differences between males and females wearing trousers. As the bulk of the person's clothing increased, the drag increased by as much as 40%.
Psychological e f f e c t s - post-strain
Penwarden, Grigg and Rayment (1978) also determined the drag coefficient of clothed man. This coefficient varies between 1-08 (0.95) for females wearing skirts to 1.33 (1 "12)
Air motion The relationship between air stream velocity and the psychological effect it causes is presented in Table 1. It
Table 1: Summary of streaming effects on people based on the Beaufort Scale
Scale
Number
Calm, light air
0'1
Air velocity (m/s) 0-
1'5
Effects Dynamic
Psychical
Calm, no noticeable air streaming
Comfort
Light breeze
2
1"6- 3'3
Wind felt on face
Moderate discomfort
Gentle breeze
3
3"4- 5.4
Wind extends light flag Hair is disturbed. Clothing flaps
Discomfort
Moderate breeze
4
5 ' 5 - 7'9
Raises dust; dry soil and loose paper Hair disarranged
Considerable discomfort
Fresh breeze
5
8.0-10.7
Force of wind felt on body Drifting snow becomes airborne Limit of agreeable wind on land
Considerable discomfort
Umbrellas used with difficulty Hair blown straight Difficult to walk steadily Wind noise on ears unpleasant Windborne snow above head height (blizzard)
Considerable discomfort
Strong breeze
6
10.8-13.8
Near gale
7
13"9-17.1
Inconvenience felt when walking
Considerable discomfort
Gale
8
17.2-20.7
Generally impedes progress Great difficulty with balance in gusts
Considerable discomfort
Strong gale
9
20"8-24"4
People blown over by gusts
Considerable discomfort
122
Applied Ergonomics
June 1984
should be noted, however, that this relationship is very general and does not take into account, for example, the psychological effects produced by the effect of wind on other environmental components.
Stress
Hypothalamus
Colour scheme of space The psychological effects of the colour and texture of the environment are very complex. The visual perception of colours produces, among other effects, the feeling of warmth or cold which modifies the sensations evoked by the hygro-thermal microclimate.
Pituitary
Red, orange, ochre and yellow colours are warm, as are surfaces finished with wood and fabrics (or have that appearance). Green and blue colours are cold, as are surfaces actually or apparently made of stone, glass, metals and other materials which people normally experience as being cold.
Adrenal
Stomach
Warm colours are dynamic, initiate activity and can produce a short-term increase in performance. Cold colours are passive, stimulate spiritual concentration and a longer stability in performance (Stejskal, 1976).
(with ulcer)
Thymus Lightness
White
Fig. 6
r,
aturotion
Hue
The basic pathways of immediate psychological response of the human organism to stress (Selye, 1974)
The overall colour scheme of the environment evokes, for example, the feelings of spaciousness or cramped conditions, cosiness and security or being lost in space (including their aesthetic application) or participates in these sensations. Apart from that it markedly contributes to the modulation of the feelings of warmth and cold (the so-called Hawthorn effect). Fanger, Breum and Jerking (1977) endeavoured to quantify the Hawthorn effect. They found out that the subjects preferred a 0"4°C higher ambient temperature in the blue than in the red light. However, there were no differences in the values of objective physiological quantities, such as skin temperature, rectal temperature or quantity of exuded sweat. Rohles and Wells (1976) ascertained in similar basic conditions the subject's thermal sensation corresponding to a globe temperature 1"5°C higher, if the whole interior was finished in warm hues instead of merely using red light. (Apart from warm colours they used also wood cladding, wallpaper, fabrics, etc). The skin temperature has not changed, once again.
# Black
Fig. 5
The double-ended cone can be used to express colours in terms of hue, lightness and saturation
Criteria of psychological microclimate Air motion So far the only criterion used is the highest admissible air velocity which amounts to 0'5 m/s in dwelling rooms and in the majority of work rooms, 1-5 m/s in the exterior of buildings, and 3"3 m/s, if slight discomfort is permitted. In every particular case, however, the character of man's activity must be taken into account and on its basis the
Applied Ergonomics
June 1984
123
/
/
~ !
/ / [
/
I
L..J ~ ~ ~
Silent/
~ ~ \ \ \ \
Unquiet \ Aggressive Irritable Unsteady Impulsive Trustful
I"1
Stiff Severe Suspicious Starched f Unsociable /
Choleric I
Unirritable\ Deliberate ~ Wary ~ Peaceful Moderate Reliable
/ ~ --
-1 I
\ \ \ \
~,,~vigorous ,
I~PhlMelanch°lic egrnatci Sanguine/ /
Colour scheme of space The criteria of the colour scheme with reference to its thermal effect are limited so far on the differentiation of markedly warm and markedly cold colours in accordance with the Tektronix Colour Standard. The purely warm colours have a hue of H = 120 ° - 180 °, the cold colours H = 2 4 0 0 - 0 ° for the lightness within the range of L = 2 9 - 7 0 and a saturation within the range of S = 5 0 - 1 0 0 .
/
,
I
J Extr°vert ~---1 Social . . / Communicative / Talkative / Accessible / Unstressed / Agile /
M e t h o d o l o g y of investigation Methodology in investigating the stressor
Air motion investigations The methodology of air motion investigations consists in the determination of two principal quantities, viz, the air velocity and the aerodynamics of the interior and exterior of buildings. The air velocity is measured with anemometers which are dealt with in detail in special publications (e g, Jokl, 1977).
Fig. 7 Psychological condition of man in relation to various psychological types. (Tilleard-Cole, 1979)
decision on the maximum permissible air velocity must be made. Penwarden (1975) gives the maximum permissible velocity of 5 m/s for shopping centres in exterior.
s,~
Aerodynamics are investigated on models, on the scales of 1 : 100 or 1 : 200, as a rule, in so-called wind tunnels. Fig. 8 shows a special wind tunnel built for this purpose in the Building Research Establishment in Garston (BRE, 1974-1975). It is recommended that a prediction should be made of air flow in the air tunnel at the very beginning of the design of every building, i e, to determine the aerodynamics of its interior and its exterior.
~liegm
Stae of eCdktter ~ Tutm
!~
St~me ch~e= w
A )
h
¸ t/eflt* ~urtttatde
Fig. 8
Wind tunnel
124
Applied Ergonomics
investigation of the aerodynamics of
June 1984
buildings
Colour scheme investigations The hue, lightness and saturation of colours can be determined either by a comparison with the respective standard samples, such as Tektronix, or by direct measurements using calorimeters which are dealt with in special publications.
Methodology in investigating strain The discussion is limited here to a consideration of the physiological factors of psychological strain. Sirains as measured by adrenaline production (and other biochemicals) have specific methodologies associated with them. There are, however, other indices of psychological strain, for example, change in pupil diameter. Equipment based on this measurement is shown in Fig. 9. The subject is exposed to some psychological stress (presented, for example, on the screen) and the reaction of his or her pupil (the change of its diameter) is automatically recorded and further evaluated by a computer.
overall psychological (including the aesthetic) effects (strains) of the environment in a very complex way, there is no simple system of optimisation of the colour scheme of environment. The design of colour schemes of the built environment forms part, primarily, of an integral concept of architectural design. The recognised importance of colour scheme in environmental design, and the large amount of experience which has been gained in designing colour schemes, has led to institutions being set up in a number of countries. These include the British Colour Council in England, the Centre d'Information de la Couleur in Paris, Instittlt ftir Farbenpsychologic in Marquartstein in Bavaria, the Institute Technology and Colour in Warsaw, Barva in oblika in Yugoslavia, the Colour Association of the United States Inc in New York, and others.
Bibliography
Baran, U Optimisation of psychological microclimate
Optimisafion of air motion The optimisation of aerodynamics of interiors is dealt with by publications on ventilation (e g, Jokl, 1981). For the optimisation of exteriors the most effective measures include: (a)
the orientation of buildings perpendicularly to the direction of prevailing winter wind,
(b)
the grouping of buildings into closed patterns,
(c)
the protection of pedestrian zones with roofs and canopies deflecting the wind away from pedestrian areas,
(d)
the siting of tall buildings on a podium of low buildings so that the increased wind velocity which will inevitably be produced will be confined to the roof of the podium, where it will be less troublesome.
Optimisadon of colour scheme Since the stress factors of the colour scheme, of a physical environment and its components, participate in the
,
v ewng eye'
/
F~~ I ,
T V c a m e r a viewing scene beln~Jobserved by Sublect
,
urn no or S u b ect
Marker spot indic(]ring eye tion
i co~,~o i
i~l~fd ]
T V monitor
showing scene TV monitor showing eye
Pupil ~ Vet , , diameter Eye positio~ Anc]locjue o r digital form
TO chart
Davis, S., and Metrick, L. 1978 Tekscope, 10.4, 7-9. An easy language for talking with colour machines.
Fanger, P.O., Breum, N.O., and Jerking, E. 1977 Ergonomics, 20.1, 11-18. Can odour and noise influence man's thermal comfort? Jokl, M. 1977 Standard methodology of investigation of hygrothermal microclimate (In Czech). Annex 18. Acta hygienica, epidemiologica et microbiologica, 7, Prague, IHE pp 63. Jokl, M. 1980 Formation of zones with high air velocity in the proximity of tall buildings (In Czech). In: IXth Conference on Biosphere, House of Technology, Czechoslovak Technical Association, Prague, pp 240243.
Joke, M. 1981 Internal microclimate, ventilation and air-conditioning technology for building engineers (In Czech). Textbook. Technical University, Prague, 167 pp. Krivohlavy, J. 1973 Conflicts among people. (In Czech). Praha, Avicenum, pp 304.
Screen or other presentation
TVcamera ~
1978 Audiovisual means (in Czech), Prague, Czechoslovakia Technical Association, pp 133-154.
recorders or computer
Penwarden, A. 1975 BRENews 9, 33, 4-6. Curbing high-rise winds. Penwarden, A.D., Grigg, P.F., and Rayment, R. 1978 Building and Environment 13, 75-84. Measurements of wind drag on people standing in a wind tunnel.
Rohles, F.H., and Wells, W.V. 1976 J of Interior Design, Education and Research, 2, 36-53. Interior design, comfort and thermal sensitivity.
Rohles, F.H., and Wilson, L.M. 1973 Behaviour XLVIII, 123-130. Hunger as a catalyst in aggression.
Fig. 9
Pupilometric apparatus of Whittaker Corporation, Space Science Division, USA. (H. Albrecht, 8000 Munich, 19, Montenstrasse9, FRG)
Selye, H. 1974 Stress without distress. J.B. Lippincott Co, Philadelphia and New York, pp 171.
Applied Ergonomics
June 1984
125
Stejskal, L. 1976 Bezpe~nd Drdca 7.2, 56-58. The utilisation of colours for improvement in occupational safety and comfort at the workplace. (In Czech.) Stevens, A. 1976 BRENews, 10.36, 11-13. How accurate is building? Stverak, J. 1966 Changes of some physiological functions and mental performance in a non-acclimatised human organism
exposed to high temperatures. (In Czech). Thesis for the degree of Candidate of Sciences. Prague, ULZ, pp 102. Tilleard-Cole, R.-R. 1979 Hexagon-Roche, 7,2, 1-7. PersSnlichkeitsas ekte in medizin schen Umgang.
BRE 1974-75 BRENews, 8,3(I, 8-9. New wind t u n n e l . . , and wind rover.
Conference Aoplied physiology and ergonomics
Sen (Hon Secretary General of the Organising Committee).
Calcutta, 17-19 August 1983
The inaugural session was followed by the Prof S.C. Mahalanobis Memorial Oration. The oration was delivered by Prof G.W. Crockford, of the London School of Hygiene and Tropical Medicine, who spoke on current research in the field of thermal comfort, and the design of protective clothing for use in extreme thermal environments.
The International Symposium on Applied Physiology and Ergonomics was held between 17-19 August 1983, at the Regional Labour Institute, Calcutta. The Symposium was jointly organised by the Physiological Society of India, the Department of Physiology (University of Calcutta), the Directorate of Factories (Government of West Bengal), and the Regional Labour Institute (Government of India). The Symposium was inaugurated by His Excellency, Shri P.D. Pande, the Governor of West Bengal. The ViceChancellor of Calcutta University, Dr R.K. Poddar, presided over the inaugural session. Addresses were also delivered by Dr S.S. Ramaswamy (Director-General, Factories Advisory Service & Labour Institute, Govt of India), Prof P.K. Banerjee (President, Physiological Society of India), Shri N. Krishnamoorthi (Labour Secretary to the Govt of West Bengal), and Dr R.N.
126
AppliedErgonomics
The scientific transactions of the Symposium started from the afternoon of 17 August and continued until the evening of 19 August. Ninety-six papers were presented in the different sessions on Endocrinology, Reproductive Physiology, Applied Nutrition, Respiratory Physiology, Applied Biochemistry, Applied Pharmacology, Applied Neuroscience, Industrial Ergonomics, Design Ergonomics, Work Physiology, Environmental Physiology (Thermal), Environmental Physiology (Altitude), Sports Physiology, Occupational Health, and Industrial Safety.
June 1984
Apart from these, papers on instrumentation and bio-technology were presented at a special session on instrumentation, and a second special session, covering the teaching of Physiology, was held on 19 August. The Amulya Ratan Memorial Oration was delivered by Prof Dr Sachchidananda Banerjee. One hundred and thirty delegates participated, representing five countries and the International Labour Organisation. The Symposium received widespread publicity from Doordarshan, and All India Radio, which broadcast interviews with the delegates over and above the usual news coverage. Reports of the Symposium were carried by the major newspapers. A volume containing the Abstracts of the papers submitted for presentation was published and distributed. The proceedings of the Symposium are being published. According to the opinions of the delegates, the Symposium was a grand success. An excellent exhibition of books on Ergonomics, Occupational Health and Safety was also organised.
Dr R.N. Sen
The psychological effects on man of air movement and the colour of his surroundings M.V. Jokl Faculty of Engineering, Technical University of Prague, Czechoslovakia
The psychological microclimate is a term which is used to describe the specific psychological effects of some environmental a.qents as well as the psychological effects of other factors of the physical environment (e g, colour of surroundings, etc). This paper considers air motion and colour schemes of space, defines their stress and strain factors, describes the psychological effects - post-strain, and the methodology of their investigation. It further sugqests the criteria and limiting and optimum values of the dynamic effect of air (permissible air velocities in interior and exterior environments) and the colour scheme of space (in accordance with the Tektronix standard). In conclusion the paper sums up the possibilities of optimisation of the 'psychological microclimate'.
Kevwords: Environment (working), air flow, colour schemes Introduction The psychological microclimate is affected by both specific environmental agents within the microclimate and other additional effects of the microclimate. All constituents of the microclimate can have a psychological effect. This includes hygro-thermal conditions (e g, dissatisfaction with heat or unsuitable heating conditions, inability to concentrate, fear of cold), odours (e g, pleasant and unpleasant odours, warning effect of odours) and the electroionic environment (which is believed to produce headaches which can have psychological effects such as aggression). Air motion, not as a bearer of heat or aerosols, but by its effect as a wind or draught, can also have an effect. In addition, the space with its three dimensions, plan, size and colour scheme, also man himself (Krivohlavy, 1973) as a component of the human environment of others, represents a further factor which can influence the psychological microclimate. A great role is also played by the accuracy of room construction (Stevens, 1976 - see Fig. 1). The lack of straightness of walls, level of floors or other surfaces, uneven flooring, gaps between panels, warped windows and doors and other defects of construction represent further significant factors which contribute to the psychological environment. The 'psychological microclimate' not only influences the physical condition of man in a certain microclimate but also affects the feelings of physical comfort or discomfort. For example, Stverak (1966) ascertained that during the exposure of the human organism to heat (globe temperatures of up to 50°C) the feeling of excessive heat strain can be accompanied by a heavy psychological experience (e g, as when reading an exciting mystery story) (Fig. 2). The
psychological microclimate also contributes to the creation of the feeling of human comfort. For example, when considering the hygro-thermal environment, the optimum hygro-thermal condition may not be sufficient to create hygro-thermal comfort. Optimum psychological conditions are also required. NOTE: The term 'psychological microclimate' is not used in the same sense as for example 'hygro-thermal microclimate', which affects man by heat and humidity. Psychological microclimate is used in the sense of 'that which is affected by the microclimate' (i e, the psyche of man).
Psychological stress due to air motion and colour scheme of space Air motion In a hygro-thermal environment, air motion can cause cooling or warming effects due to heat transfer by convection. The air flow, however, can also produce unpleasant sensations independently of these effects, due to its dynamic effect (e g, by undesirable effects on clothing) (Fig. 3). It can, for example, cause upturning of umbrellas or disturb the leaves of a book one is reading, particularly in the vicinity of tall buildings (Penwarden, 1975). The dynamic effect of air is characterised by the: (a)
frequency, direction and speed of air flows.
(b)
configuration of the space in which the air flows occur (e g, there is often an interaction between the configuration of the ground and of architectural works)
0003-6870/84/02 0119-08 $03.00 O 1984 Butterworth & Co (Publishers) Ltd
Applied Ergonomics
dune 1984
119
Is it straight ?
Is it level ?
Is it vertical ?
Will it fit ?
Is it flat ? Accuracy in building
Fig. 1
(c)
configuration of the surfaces of the exposed subject (e g, his clothing) which, however, ranges among the factors of strain.
Frequency, direction and speed of air flow
Analysis of these factors reveals that they can be replaced with a single quantity - the mean air velocity (Penwarden, 1975). For outdoor environments these factors are recorded by the nearest meteorological station.
The level of accuracy of interior dimensions (Stevens, 1976)
of the tall building H, the so-called R H ratio. For tall buildings, its value amounts to 0.5 for the vortex flow, 1.0 for the corner streams and 1"2 for the concentrated throughflow. For low rise buildings it comes between 0-3 and 0.4. Thus a person walking from a sheltered region of low rise building may experience a fourfold increase of air velocity on entering a passageway beneath a tall building (Jokl, 1980).
Colour scheme of space
Configuration of space In external environments a dominant role is played by tall buildings, not only because of their height and location, but also with respect to their position in relation to other buildings and structures. In a space of interest, there are three principal regions of increased air velocity (Fig. 4). These are, the vortex flow, the corner streams and the concentrated through-flow. The vortex flow originates behind a low rise building, the concentrated through-flow and the corner streams are due to the congestion of stream lines around the tall building. These are due to the effect of passages and corners of the building and to the diversion of the air flow downwards, to the pedestrian level, as a result of which they are also a function of the height of the building. The absolute value of air velocity is replaced with the ratio of the air velocity at pedestrian level to the wind velocity at the top
120
Applied Ergonomics
June 1984
The colour scheme of any component of environment can be characterised by the following quantities: hue, lightness and saturation. The difference among them is illustrated in Fig. 5 (Davis and Metrick, 1978). Colour of surface and colour of light
One of the factors contributing to psychological stress is the perceived colour of the surface or the light reflected from the surface, which is the result of an interaction of the colour of the surface and the colour of light incident on the surface. Material on the surface
Materials are characterised by their colour and this is accentuated by the surface texture.
r!
!/ P
I' I L
!ri
r I'
/' I ' i
( i' rL b r f~
t'J
,!
f
f L
iI I
example, an unusual eolour scheme may be perceived as being 'dirty' (actual or apparent). Psychological strain may motivate and even influence, in the long run, the psyche of man. It may also influence the physiological state of the human organism, which may manifest itself, for instance, in the endocrine system by direct strain on the stomach and on the production of adrenaline and other hormones which mobilise the whole organism (Selye, 1974). (Fig. 6). Psychological strain, produced by environmental components, is modulated by the psychological condition of man (Fig. 7), his physiological state, (e g, hunger (Rohles and Wilson, 1973)), his previous experience and his habits and customs. The dynamic effects of air motion can also produce psychological strain which depends upon the configuration of the surface of the exposed subject (e g, his clothing).
Configuration of the surface of the exposed subject Moving air affects an exposed subject by the force F which is determined by the relationship: p v~ F = A CD (S) 2 Where A
- projected area normal to the air stream (m=)
CD
- drag coefficient (ND)
p
- air density (kg/m 3)
v
- air velocity (m/s).
Since the variations of air density will not be significant in the majority of cases, the dynamic effect of air on the subject depends primarily on air velocity and on the drag coefficient of the subject and his projected area normal to the air stream. If the exposed subject is man, his projected area normal to the air stream can be determined from his total surface. Fig. 2
With the simultaneous effect of various microclimate components on the subject, the psychological microclimate should not be overlooked
Combination of colours
In multi-coloured surfaces the combination of colours play a role of importance which can be assessed with reference to: (a)
so-called complementary combinations (e g, the combination of yellow and blue).
(b)
saturated and non-saturated colours (e g, the combination of saturated blue and pastel blue).
(c)
colours of different lightness (e g, the combination of light blue and dark blue).
Factors of psychological strain If the components of an environment produce psychological effects on man then the perception of those components is more intense (by aperception, i e, due to experience, associations, evaluation, anticipation, etc), than that experienced by sensory perception alone. This involves very complicated and heavily subjective processes. For
Fig. 3
Psychological effect of streaming air
Applied Ergonomics
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121
~,~~ Three main areas of increased wind velocity around a tall building (Penwarden, 1975)
Fig. 4
According to Penwarden, Grigg and Rayment (1978), this projected area will be: (a) (b)
~Conres-reto
if facing the air stream: AF = 0.35ADu =0"0269 W0"425.H0725
(m 2)
if sideways to the air stream: A = 0"26ADu = 0.0200 W0"425j-/0"725
(m 2)
where total surface of a nude body (DuBois area),
ADu
-
IV
- weight of man (kg)
H
- height of man (m)
(m 2)
for males and females wearing trousers and a flapping coat. The aforementioned figures refer to the persons facing the air stream (sideways to the air stream) respectively, the average value for 331 persons being 1-16 (1.01) with the possible deviation of as much as 15% for various types of clothing. The drag coefficient for persons wearing trousers (1-18 and 1 "02 respectively) was 7 - 10% higher than the same coefficient for persons wearing skirts (1 "08 and 0.95 respectively). There were no differences between males and females wearing trousers. As the bulk of the person's clothing increased, the drag increased by as much as 40%.
Psychological e f f e c t s - post-strain
Penwarden, Grigg and Rayment (1978) also determined the drag coefficient of clothed man. This coefficient varies between 1-08 (0.95) for females wearing skirts to 1.33 (1 "12)
Air motion The relationship between air stream velocity and the psychological effect it causes is presented in Table 1. It
Table 1: Summary of streaming effects on people based on the Beaufort Scale
Scale
Number
Calm, light air
0'1
Air velocity (m/s) 0-
1'5
Effects Dynamic
Psychical
Calm, no noticeable air streaming
Comfort
Light breeze
2
1"6- 3'3
Wind felt on face
Moderate discomfort
Gentle breeze
3
3"4- 5.4
Wind extends light flag Hair is disturbed. Clothing flaps
Discomfort
Moderate breeze
4
5 ' 5 - 7'9
Raises dust; dry soil and loose paper Hair disarranged
Considerable discomfort
Fresh breeze
5
8.0-10.7
Force of wind felt on body Drifting snow becomes airborne Limit of agreeable wind on land
Considerable discomfort
Umbrellas used with difficulty Hair blown straight Difficult to walk steadily Wind noise on ears unpleasant Windborne snow above head height (blizzard)
Considerable discomfort
Strong breeze
6
10.8-13.8
Near gale
7
13"9-17.1
Inconvenience felt when walking
Considerable discomfort
Gale
8
17.2-20.7
Generally impedes progress Great difficulty with balance in gusts
Considerable discomfort
Strong gale
9
20"8-24"4
People blown over by gusts
Considerable discomfort
122
Applied Ergonomics
June 1984
should be noted, however, that this relationship is very general and does not take into account, for example, the psychological effects produced by the effect of wind on other environmental components.
Stress
Hypothalamus
Colour scheme of space The psychological effects of the colour and texture of the environment are very complex. The visual perception of colours produces, among other effects, the feeling of warmth or cold which modifies the sensations evoked by the hygro-thermal microclimate.
Pituitary
Red, orange, ochre and yellow colours are warm, as are surfaces finished with wood and fabrics (or have that appearance). Green and blue colours are cold, as are surfaces actually or apparently made of stone, glass, metals and other materials which people normally experience as being cold.
Adrenal
Stomach
Warm colours are dynamic, initiate activity and can produce a short-term increase in performance. Cold colours are passive, stimulate spiritual concentration and a longer stability in performance (Stejskal, 1976).
(with ulcer)
Thymus Lightness
White
Fig. 6
r,
aturotion
Hue
The basic pathways of immediate psychological response of the human organism to stress (Selye, 1974)
The overall colour scheme of the environment evokes, for example, the feelings of spaciousness or cramped conditions, cosiness and security or being lost in space (including their aesthetic application) or participates in these sensations. Apart from that it markedly contributes to the modulation of the feelings of warmth and cold (the so-called Hawthorn effect). Fanger, Breum and Jerking (1977) endeavoured to quantify the Hawthorn effect. They found out that the subjects preferred a 0"4°C higher ambient temperature in the blue than in the red light. However, there were no differences in the values of objective physiological quantities, such as skin temperature, rectal temperature or quantity of exuded sweat. Rohles and Wells (1976) ascertained in similar basic conditions the subject's thermal sensation corresponding to a globe temperature 1"5°C higher, if the whole interior was finished in warm hues instead of merely using red light. (Apart from warm colours they used also wood cladding, wallpaper, fabrics, etc). The skin temperature has not changed, once again.
# Black
Fig. 5
The double-ended cone can be used to express colours in terms of hue, lightness and saturation
Criteria of psychological microclimate Air motion So far the only criterion used is the highest admissible air velocity which amounts to 0'5 m/s in dwelling rooms and in the majority of work rooms, 1-5 m/s in the exterior of buildings, and 3"3 m/s, if slight discomfort is permitted. In every particular case, however, the character of man's activity must be taken into account and on its basis the
Applied Ergonomics
June 1984
123
/
/
~ !
/ / [
/
I
L..J ~ ~ ~
Silent/
~ ~ \ \ \ \
Unquiet \ Aggressive Irritable Unsteady Impulsive Trustful
I"1
Stiff Severe Suspicious Starched f Unsociable /
Choleric I
Unirritable\ Deliberate ~ Wary ~ Peaceful Moderate Reliable
/ ~ --
-1 I
\ \ \ \
~,,~vigorous ,
I~PhlMelanch°lic egrnatci Sanguine/ /
Colour scheme of space The criteria of the colour scheme with reference to its thermal effect are limited so far on the differentiation of markedly warm and markedly cold colours in accordance with the Tektronix Colour Standard. The purely warm colours have a hue of H = 120 ° - 180 °, the cold colours H = 2 4 0 0 - 0 ° for the lightness within the range of L = 2 9 - 7 0 and a saturation within the range of S = 5 0 - 1 0 0 .
/
,
I
J Extr°vert ~---1 Social . . / Communicative / Talkative / Accessible / Unstressed / Agile /
M e t h o d o l o g y of investigation Methodology in investigating the stressor
Air motion investigations The methodology of air motion investigations consists in the determination of two principal quantities, viz, the air velocity and the aerodynamics of the interior and exterior of buildings. The air velocity is measured with anemometers which are dealt with in detail in special publications (e g, Jokl, 1977).
Fig. 7 Psychological condition of man in relation to various psychological types. (Tilleard-Cole, 1979)
decision on the maximum permissible air velocity must be made. Penwarden (1975) gives the maximum permissible velocity of 5 m/s for shopping centres in exterior.
s,~
Aerodynamics are investigated on models, on the scales of 1 : 100 or 1 : 200, as a rule, in so-called wind tunnels. Fig. 8 shows a special wind tunnel built for this purpose in the Building Research Establishment in Garston (BRE, 1974-1975). It is recommended that a prediction should be made of air flow in the air tunnel at the very beginning of the design of every building, i e, to determine the aerodynamics of its interior and its exterior.
~liegm
Stae of eCdktter ~ Tutm
!~
St~me ch~e= w
A )
h
¸ t/eflt* ~urtttatde
Fig. 8
Wind tunnel
124
Applied Ergonomics
investigation of the aerodynamics of
June 1984
buildings
Colour scheme investigations The hue, lightness and saturation of colours can be determined either by a comparison with the respective standard samples, such as Tektronix, or by direct measurements using calorimeters which are dealt with in special publications.
Methodology in investigating strain The discussion is limited here to a consideration of the physiological factors of psychological strain. Sirains as measured by adrenaline production (and other biochemicals) have specific methodologies associated with them. There are, however, other indices of psychological strain, for example, change in pupil diameter. Equipment based on this measurement is shown in Fig. 9. The subject is exposed to some psychological stress (presented, for example, on the screen) and the reaction of his or her pupil (the change of its diameter) is automatically recorded and further evaluated by a computer.
overall psychological (including the aesthetic) effects (strains) of the environment in a very complex way, there is no simple system of optimisation of the colour scheme of environment. The design of colour schemes of the built environment forms part, primarily, of an integral concept of architectural design. The recognised importance of colour scheme in environmental design, and the large amount of experience which has been gained in designing colour schemes, has led to institutions being set up in a number of countries. These include the British Colour Council in England, the Centre d'Information de la Couleur in Paris, Instittlt ftir Farbenpsychologic in Marquartstein in Bavaria, the Institute Technology and Colour in Warsaw, Barva in oblika in Yugoslavia, the Colour Association of the United States Inc in New York, and others.
Bibliography
Baran, U Optimisation of psychological microclimate
Optimisafion of air motion The optimisation of aerodynamics of interiors is dealt with by publications on ventilation (e g, Jokl, 1981). For the optimisation of exteriors the most effective measures include: (a)
the orientation of buildings perpendicularly to the direction of prevailing winter wind,
(b)
the grouping of buildings into closed patterns,
(c)
the protection of pedestrian zones with roofs and canopies deflecting the wind away from pedestrian areas,
(d)
the siting of tall buildings on a podium of low buildings so that the increased wind velocity which will inevitably be produced will be confined to the roof of the podium, where it will be less troublesome.
Optimisadon of colour scheme Since the stress factors of the colour scheme, of a physical environment and its components, participate in the
,
v ewng eye'
/
F~~ I ,
T V c a m e r a viewing scene beln~Jobserved by Sublect
,
urn no or S u b ect
Marker spot indic(]ring eye tion
i co~,~o i
i~l~fd ]
T V monitor
showing scene TV monitor showing eye
Pupil ~ Vet , , diameter Eye positio~ Anc]locjue o r digital form
TO chart
Davis, S., and Metrick, L. 1978 Tekscope, 10.4, 7-9. An easy language for talking with colour machines.
Fanger, P.O., Breum, N.O., and Jerking, E. 1977 Ergonomics, 20.1, 11-18. Can odour and noise influence man's thermal comfort? Jokl, M. 1977 Standard methodology of investigation of hygrothermal microclimate (In Czech). Annex 18. Acta hygienica, epidemiologica et microbiologica, 7, Prague, IHE pp 63. Jokl, M. 1980 Formation of zones with high air velocity in the proximity of tall buildings (In Czech). In: IXth Conference on Biosphere, House of Technology, Czechoslovak Technical Association, Prague, pp 240243.
Joke, M. 1981 Internal microclimate, ventilation and air-conditioning technology for building engineers (In Czech). Textbook. Technical University, Prague, 167 pp. Krivohlavy, J. 1973 Conflicts among people. (In Czech). Praha, Avicenum, pp 304.
Screen or other presentation
TVcamera ~
1978 Audiovisual means (in Czech), Prague, Czechoslovakia Technical Association, pp 133-154.
recorders or computer
Penwarden, A. 1975 BRENews 9, 33, 4-6. Curbing high-rise winds. Penwarden, A.D., Grigg, P.F., and Rayment, R. 1978 Building and Environment 13, 75-84. Measurements of wind drag on people standing in a wind tunnel.
Rohles, F.H., and Wells, W.V. 1976 J of Interior Design, Education and Research, 2, 36-53. Interior design, comfort and thermal sensitivity.
Rohles, F.H., and Wilson, L.M. 1973 Behaviour XLVIII, 123-130. Hunger as a catalyst in aggression.
Fig. 9
Pupilometric apparatus of Whittaker Corporation, Space Science Division, USA. (H. Albrecht, 8000 Munich, 19, Montenstrasse9, FRG)
Selye, H. 1974 Stress without distress. J.B. Lippincott Co, Philadelphia and New York, pp 171.
Applied Ergonomics
June 1984
125
Stejskal, L. 1976 Bezpe~nd Drdca 7.2, 56-58. The utilisation of colours for improvement in occupational safety and comfort at the workplace. (In Czech.) Stevens, A. 1976 BRENews, 10.36, 11-13. How accurate is building? Stverak, J. 1966 Changes of some physiological functions and mental performance in a non-acclimatised human organism
exposed to high temperatures. (In Czech). Thesis for the degree of Candidate of Sciences. Prague, ULZ, pp 102. Tilleard-Cole, R.-R. 1979 Hexagon-Roche, 7,2, 1-7. PersSnlichkeitsas ekte in medizin schen Umgang.
BRE 1974-75 BRENews, 8,3(I, 8-9. New wind t u n n e l . . , and wind rover.
Conference Aoplied physiology and ergonomics
Sen (Hon Secretary General of the Organising Committee).
Calcutta, 17-19 August 1983
The inaugural session was followed by the Prof S.C. Mahalanobis Memorial Oration. The oration was delivered by Prof G.W. Crockford, of the London School of Hygiene and Tropical Medicine, who spoke on current research in the field of thermal comfort, and the design of protective clothing for use in extreme thermal environments.
The International Symposium on Applied Physiology and Ergonomics was held between 17-19 August 1983, at the Regional Labour Institute, Calcutta. The Symposium was jointly organised by the Physiological Society of India, the Department of Physiology (University of Calcutta), the Directorate of Factories (Government of West Bengal), and the Regional Labour Institute (Government of India). The Symposium was inaugurated by His Excellency, Shri P.D. Pande, the Governor of West Bengal. The ViceChancellor of Calcutta University, Dr R.K. Poddar, presided over the inaugural session. Addresses were also delivered by Dr S.S. Ramaswamy (Director-General, Factories Advisory Service & Labour Institute, Govt of India), Prof P.K. Banerjee (President, Physiological Society of India), Shri N. Krishnamoorthi (Labour Secretary to the Govt of West Bengal), and Dr R.N.
126
AppliedErgonomics
The scientific transactions of the Symposium started from the afternoon of 17 August and continued until the evening of 19 August. Ninety-six papers were presented in the different sessions on Endocrinology, Reproductive Physiology, Applied Nutrition, Respiratory Physiology, Applied Biochemistry, Applied Pharmacology, Applied Neuroscience, Industrial Ergonomics, Design Ergonomics, Work Physiology, Environmental Physiology (Thermal), Environmental Physiology (Altitude), Sports Physiology, Occupational Health, and Industrial Safety.
June 1984
Apart from these, papers on instrumentation and bio-technology were presented at a special session on instrumentation, and a second special session, covering the teaching of Physiology, was held on 19 August. The Amulya Ratan Memorial Oration was delivered by Prof Dr Sachchidananda Banerjee. One hundred and thirty delegates participated, representing five countries and the International Labour Organisation. The Symposium received widespread publicity from Doordarshan, and All India Radio, which broadcast interviews with the delegates over and above the usual news coverage. Reports of the Symposium were carried by the major newspapers. A volume containing the Abstracts of the papers submitted for presentation was published and distributed. The proceedings of the Symposium are being published. According to the opinions of the delegates, the Symposium was a grand success. An excellent exhibition of books on Ergonomics, Occupational Health and Safety was also organised.
Dr R.N. Sen