lighting engineering 13 vol6 2004

8/13/2019 Lighting Engineering 13 Vol6 2004

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INGINERIA ILUMINATULUI 13-2004 1

INGINERIA ILUMINATULUILighting Engineering

Vol. 6, No. 13 Summer, September 2004

3 Editorial Advanced daylighting systems human behaviour and costsFlorin POP

5 Influence of daylighting and supplementary electric lighting on energy needs in office buildingsGilbert ACHARD, Christelle FRANZETTI, Oana DOBRE, Gilles FRAISSE

23 Researches concerning the influence of monochromatic LED-type light on the productivityperformances, quality of the carcasses, health and methabolic profile of the broiler chickensGheorghe CMPEANU, Maria COSTEI, Ion VIAN, Stelian MATEI, Nicoleta CIOCRLIE,

Alina ORAN, Emanuela PETRE33 Analysis of power quality parameters of the lighting sistems with fluorescent lamps

Ion MIRCEA, Denisa RUINARU

Doctorate thesis

41 Chromatic integration of architectural and ornamental lighting in the urban environmentSandor ORBAN

Conferences and symposiums

43 The 3rdInternational Lighting Conference ILUMINAT 2005 & The 3rdBalkan Conference onLighting BALKANLIGHT 2005, Cluj-Napoca, June 2-3, 2005, Second announcement

45 The XII National Conference LIGHT 2004, Varna, BulgariaPlamen TSANKOV

Information

47 White colour with LEDs concepts and methods for efficient solid-state lighting

Stelian MATEI59 Lighting Engineering Center LEC UTC-NFlorin POP

61 Lighting in the New World. LEDs - A Bright New WorldCristian UVGU


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INGINERIA ILUMINATULUI 13-20042

INGINERIA ILUMINATULUI

Anul 6, Numrul 13 - Vara, Septembrie 2004

3 Editorial Sisteme de iluminat natural avansate comportament i costuriFlorin POP

5 Influena iluminatului natural i a iluminatului electric suplimentar asupra necesarului deenergie n cldirile de birouriGilbert ACHARD, Christelle FRANZETTI, Oana DOBRE, Gilles FRAISSE

23 Cercetri privind influena luminii monocromatice de tip LED asupra performanelorproductive, calitii carcaselor i strii de sntate a puilor broiler

Gheorghe CMPEANU, Maria COSTEI, Ion VIAN, Stelian MATEI, Nicoleta CIOCRLIE,Alina ORAN, Emanuela PETRE33 Analiza parametrilor calitativi ai sistemelor de iluminat cu lmpi fluorescente

Ion MIRCEA, Denisa RUINARU

Teze de doctorat

41 Integrarea cromatic a iluminatului arhitectural i ornamental n mediul urbanandor ORBAN

Conferine i simpozioane

43 A-3-a Conferin Internaional de Iluminat ILUMINAT 2005 & A 3-a Conferin Balcanic niluminat BALKANLIGHT 2005, Cluj-Napoca, 2-3 Iunie, 2005,Al doilea anun

45 A XII-a Conferin Naional LIGHT2004, Varna, BulgariaPlamen TSANKOV

Informaii

47 Culoarea alb cu LED-uri: concepte i metode n iluminarea eficient cu componente solid-stateStelian MATEI

59 Centrul de Ingineria Iluminatului UTC-NFlorin POP

61 Iluminatul n Lumea Nou. LED-urile, o Lume Nou StrlucitoareCristian UVGU


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Dr.Florin POP, Professor

A modern design for interior lighting systems hasto consider all the environmental issues a proper

electric lighting use in accordance with the daylightavailability, energy, materials and equipment,maintenance programme, optimum quality of thelight in space (photometric and colorimetric aspects)and of the electric network (harmonics), the userscomfort and satisfaction.

Significant savings in energy consumption, andtherefore cost, of providing lighting without reducingstandards can be achieved by applying an energy-effective-design approach to lighting installations.The objective is clearly to provide lighting to the

quantity and quality standards required, with theminimum usage of electrical energy. The energyconsumed by a lighting installation depends upon theinstalled loadand the hours of use.The hours of useof a lighting installation depend upon the occupancy

patterns of the space, the daylight available in thespace and the control system used.

There are two natural barriers to implementan energy efficient lighting: economical andeducational. The low level of people income does not

permit the purchasing of the newest energy efficient

and good color rendering lamps. The lightingknowledge is lacking many times even through theeducated people, and there are no media-dedicated

programmes to improve it.The EN 12464 (Lighting of work places) and

EN 12665 (General terms and criteria for specifyinglighting requirements) offer a new quality offurther lighting installations responsibility of the

illumination design author for results of his work and

responsibility of the users for proper maintenance ofthe installations. Comparative with a lighting system

based on general lighting, a localised lighting system(for task area) with additional ambient lighting (forimmediate surrounding) may fall the specific powerfrom 10-15 W/m2to 6-10 W/m2, representing about50% savings [Govn 2001].

Lighting represents an important part of buildingenergy consumption in the EU around 10% ofthe total electricity consumption, ranging from5% (Belgium, Luxemburg) to 15% (Denmark, The

Netherlands, and, as well, Japan). The global electriclighting energy use may be split in four sectors:services 48%, residential 28%, industrial 16% andstreet lighting and other 8% [Mills 2002]. Lightingsystems design trends are dynamics both in time and

between countries. The recommended illuminancelevel represents only one of the design parameters,

but it is determinant for a lighting system and itsenergy consumption [Mills & Borg 1998].

Lighting electricity consumption accounts forabout 20 to 30% of the total energy required by an

office building. On average, the investment cost oflighting facilities for an office building works outat around 1 to 2% of total investment. The powerdensity for standard fluorescent lighting installationsvaries from 13 to 20 W/m2. Recent progress inequipment and design demonstrates the possibilityto reduce these values in the range of 7 to 10 W/m 2.A minimum acceptable lighting power density of about7 W/m2 will leads to annual lighting consumptionof 16 kWh/m2. Dimming or extinction of lamps ofambient lighting may lead to annual consumption

below 10 kWh/m2 [Fontoynont, Escaffre & Marty2002]. Based on the few comprehensive estimatesstudies, there is stipulated an approximate commercialsector lighting savings potential in the range of 25%to 40% [Mills 2002]. In practice savings will vary bycountry, depending on existing baseline conditions.

Daylight may cover the entire lighting need invery few buildings, and, in the same time, daylighting

ADVANCED DAYLIGHTING SYSTEMS HUMAN BEHAVIOUR AND COSTS


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can make an important energy contribution for manybuildings. Both daylighting and electric lightingshould be considered when designing a new buildingand lighting installation. The lack of knowledge onthe performance of daylighting systems and lightingcontrol strategies, the lack of daylighting designtools, of evidence of the advantages of daylighting

prevent many designers to take into considerationdaylight in their building design.Direct use of daylight in buildings interior is

available for the area closed with glazed areas onthe building envelope windows, skylights. Theremote systems using light tubes or other devicesredirect daylight into deep areas of buildings, unlit

by conventional glazing.A daylighting system through windows is

concerned with the users requirements: (1) Changeand Variety- the nature of sun and sky; (2) Colour

and View - the contact with the weather and theworld outside; (3) Modelling and orientation,Sunlight effect- the mood created by the variationof light. What is offering a remote lighting systemof daylight in buildings interior? Some people stategratuity. Yes, the solar light source is free ofcosts. But, what the costs of the lighting collectorand transport systems are? And, what the efficiencyof the whole system is? Are the requirementsfor an improved mood, behaviour or well-beingunder the daylight received through a remotelighting system accomplished? Cost and energyefficiency comparison between different systemsand installations is difficult due to their diversityand complexity and the prototype character ofmany of them. The remote lighting systemsmay cost between 300 /m2 for active zenithalsystems (nearly 10 times that of a conventionalelectric lighting system) to 50-75 /m2for passivezenithal guides (which is comparable with electriclighting). The most commercially spread systemis that with the roof passive collectors, light tubestransport, and interior opalescent emitters - many

thousands of such systems world-wide. The capitalcosts are depended by the pipe configuration andaccommodation work required on building fabric.Light is distributed in an interior by emitters whichdiffer little from conventional luminaires. The

payback time for several case studies are at thelevel of 3-4 years. However many passive zenithal

systems are incapable of providing satisfactorytask illuminance and require an electric system assupplement and backup [Carter 2004].

The daylight is free, but the glazing or remotelighting systems of daylight can be very expensive. Thedaylight offered in the buildings interior by lighttubes systems is NOT THE SAME as the daylight

received through windows.Proiectarea modern a sistemelor de iluminat

interior trebuie s considere toate componenteleambientale un iluminat electric adecvat nconcordan cu disponibilitatea luminii naturale,energia, materialele de construcie i finisarei echipamentul luminotehnic, programul dentreinere, distribuia optim a luminii n spaiu(aspecte fotometrice i colorimetrice ale calitiiiluminatului), reeaua electric de alimentare(armonici), confortul i satisfacia utilizatorilor.

Lumina natural poate s asigure ntregulnecesar de iluminat n foarte puine cldiri dar, nacelai timp, poate s aduc o contribuie energeticimportant pentru multe cldiri Lipsa cunoaterii

performanelor sistemelor de iluminat natural i astrategiilor de control al iluminatului electric, a unorinstrumente de proiectare i a evidenierii avantajeloriluminatului natural constituie impedimente majore

pentru muli proiectani n considerarea luminiinaturale n proiectarea cldirilor.

Utilizarea direct a luminii naturale n interiorul

cldirilor este posibil doar pentru o zon limitat dinapropierea suprafeelor vitrate ale anvelopei cldirii- ferestre sau luminatoare. Sistemele de transportla distan a luminii utiliznd tuburi de lumin saualte dispozitive redirecioneaz lumina naturaladnc n interiorul cldirilor, n zone neiluminate desistemele convenionale de vitrare. Ce ofer unsistem de transport la distan a luminii n interiorulcldirilor? Unii susin gratuitate. Desigur, sursade lumin solar este gratuit. Dar, care suntcosturile colectorului de lumin i ale sistemului detransport? i care este eficiena ntregului sistem?

Sunt ndeplinite cerinele umane pentru un ambientconfortabil, plcut i care s determine o starede bine sub efectul unei lumini naturale primite

printr-un tub? Lumina natural este gratuit, dar sistemele

de vitrare sau de transport la distan ale luminiinaturale pot s fie foarte scumpe.


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INFLUENCE OF DAYLIGHTING AND SUPPLEMENTARY ELECTRICLIGHTING ON ENERGY NEEDS IN OFFICE BUILDINGS

Gilbert ACHARD*, Christelle FRANZETTI**, Oana DOBRE*, Gilles FRAISSE*

*

Ecole Suprieure dIngnieurs de Chambry, Universit de Savoie**Electricit de France, Lyon

Daylight and electric lighting are complementary and this coupling has to be considered in the analysisof the global energy needs of an office building because of the thermal loads generated by the electriclighting and the influence of the windows on both luminous and thermal behavior of the rooms. This

paper deals with the foreseen energy balance of an office building with regards to the technological andarchitectural solutions. A global analysis is needed for a consistent approach of Energy Demand Save

Management. The main objective is to test two linked softwares, one for luminous and the other forthermal behavior assessment, to obtain global energy needs of office buildings.

1. Introduction

It is generally assumed that about 30% of theenergy consumption of office buildings comes fromelectric lighting. In order to reduce this energyconsumption, the manufacturers propose a varietyof control systems which adjust the amount ofelectric light to the natural light entering the room,while maintaining the minimum level of illuminancewith respect to activities and visual comfort. Those

systems are said to reduce by 65%, in the bestcases, the lighting energy consumption. However,the energy interaction between lighting and airconditioning has to be considered for consistentapproach of Energy Demand Save Management.The thermal gains generated by electric lightinghave positive effects on cold periods by reducingthe needs for heating, but they increase the coolingdemand on the hot period.

Many technological or architectural solutionscan be used in order to develop and control daylight[2]. Lighting energy consumption is linked to

the switch on time of electric lighting and to theinstalled power. The reduction of lighting energyconsumption can be achieved by the choice of anefficient installation or by a better control of usetime. This is the aim of new lighting technologies.Daylight and electric lighting are complementaryand this property can be exploited to reduce energyconsumption [3].

In the perspective of environmental protection,the energy needs of a building have to be globallyconsidered. The interaction between lightingand air conditioning modulates the estimation ofenergy benefit of lighting systems. Our purposeis to identify and quantify the parameters of theinteraction phenomena to guide people in the choiceof lighting control technologies and architecturaldesign. Two linked specific softwares, one for

luminous behaviour and the other for thermalbehaviour assessment, are tested and used for thisparametric study.

2. Luminous and thermal behavior of an officebuilding

To study the modulation of the global energy benefitdue to intelligent lighting control device based onthe complementarity between electric lighting anddaylight, a lot of parameters have to be considered:architecture of the building, environment of the

building, materials involved, technologies involved,activities and comfort of people.We have selected fourteen parameters (Table 1)

with reference to a previous sensibility analysis. Theyare those which seemed us the most characteristicamong all the possible ones.


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The simulations have been conducted with acomputation tool developed by EDF and namedCA-SIS [5]. It allows the estimation of the different

energy needs (lighting, heating, cooling and global)of office buildings. The thermal behavior of buildingis simulated by TRNSYS [7] and the luminous

behavior is evaluated with a specific programmewe have developed and named LIGHT. This last

programme takes into account electric lightingwhich supplies daylight if necessary.The daylight

illuminance on the working plane is obtained bythe sum of the three components linked to the skyluminance distribution (direct, external reflected

and internal reflected components) and the onlyinternal reflected component of direct sun radiation.This last restriction corresponds to a good design ofthe faade allowing to avoid direct light from thesun on the working plane. The study of the luminous

behavior of office buildings with LIGHT give goodresults (10%) until a daylight illuminance mean

PARAMETERS HIGH LEVEL LOW LEVELClimate areaHi H1(=+1)

cold climate

H3(=-1)

very sunny climate

H1in the north and NE,H3in the SE and

H2in the rest of France.

Thermal insulation high low Those three parameters describe the

thermal property of the building and of

the materials involved.

Thermal inertia medium ligh

Radiant energy transmission rateTT

efficient (=0,8) not efficient (=0,3)

Narrow screen without with Element of the architecture which can

shades a part of the windows

External shadingML without (= +1) with (=-1) It is an element of the environment

(nearby or far-away)

relative aperture rate TV big (=0,675) little (=0,037) It takes into account the light

transmission rate (l), the area of the

windows and of the floor

Horizontal position of the windows on the right of the wall on the left of the wall The position of the window in the wall

has an influence on the distribution ofdaylight in a room.

Vertical position of the window centred high in the wall

Lighting control systemLoi clock (=+1) intelligent lighting

devices (=-1)

The system of lighting control can vary

from the basic one (clock) to the most

effective

Electric lighting powerPi 18 W/m2

(not efficient)

8 W/m2

(very efficient)

It depends on the type of lamps and

ballasts, and on the efficiency of the light

equipment

Convection/radiation ratio convection equal

radiation

more radiation than

convection

The thermal loads of electric lighting

have a convective and a radiative part.

Photometry properties of materials high luminous

reflection rate

low luminous

reflection rate

This factor acts on the internal reflected

components

Shading of the windowsSt without (=+1) with (=-1) It is a crucial parameter for the control of

glare and summer overheating

For S=-1, there is a progressive shading when external vertical

irradiance varies from 100 to 300 W.m-2[4]

Table 1List of the studied parameters(the bold type parameters are the most efficient for the reference building)


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value of 1000 lx on the working plane (see paragraph3.3). Beyond this threshold, the probability ofglare is so important that the users protect them byspecific blinds to reduce the luminance window at asuitable value. In this case, we assume that daylightilluminance is always sufficient. So, the consequenceof this daylight shading is only an alteration of the

thermal behavior because the reduction of radiantenergy transmission by the windows.The interactions between natural and electric

lighting and HVAC process can be evaluated byrelationships linking energy needs and the mostefficient parameters of Table 1.

We have chosen the experience plan method[8] to reduce the number of simulations necessaryto obtain the above relations.

For each parameter, we define a high and a lowlevel, chosen to be representative of up-to-date

office buildings in France.With a screening procedure [9], we select themost efficient parameters. Thanks to a statisticaltreatment [10] the weight of each of those parameters,

with a confidence interval, can then be estimated.As an example, we present the results for a

square-shaped and seven floors office building(reference case for the following). The total areaof the seven floors is 2800 m. All the offices areallocated on the periphery of each floor and thecommon services are in the center of the building.

The screening procedure gives a fractionalplan of only 65 experiences, compared with214 or 16,384 experiences of a complete plancorresponding to 14 parameters and 2 levels (Minand Max).

Different relations linking the most efficientparameters (Table 1) and their first order interactionswith annual lighting energy consumption or otherannual energy needs (heating-, cooling-, globalenergy needs) have been elaborated by applyingthe experience plan method. They correspond

to the following formulas, where the results are inGWh and where extensive parameters (Pi, TV, TT)correspond to reduced value varying between 0 and+1, relatively to the interval of variation:

Clighting

= (52.3 6.8) + (17.9 1.3) Pi + (9.4 1.3) Loi (4.1 1.6) TV+ (5.3 1.4) TV.Loi + (3.9 1.4) Pi.Loi + (2.3 1.4) ML.Loi

Bheating

= (239.3 23.4) + 62.8 5.5) TV (34.3 4.5) Hi (16.6 4.5) TT+ (11.5 4.6) Loi (10.6 4.5) Pi (9.7 4.8) St (22.7 4.7) TV.Loi- (11.9 4.7) Hi.TV (7.1 4.9) Hi.ML (6.3 4.5) TV.St

Bcooling

= (93.5 24) + (33.6 5.6)TV + (23.8 4.6)TT + (17.9 5)St+ (15 5)TV.TT + (12.3 4.6)TT.St + (7.3 4.8)TV.St+ (6.8 4.6)Hi.TT + (6.7 4.8)Hi.TV

Rglobal

= (385.1 35) + (92.4 8.2) TV + (22.9 6.8) Loi + (13.4 7.2) TV.TT- (13 7) TV.Loi + (10.1 7) Pi.Loi

(1)

The data of the simulations are:- required temperature for the heating: 20 C

in occupied period and 12 C in unoccupiedperiod;

- required temperature for the cooling: 24 Cin occupied period and 28 C in unoccupied

period;- required level of working plane illuminance:

500 lx.The global energy needs depend especially on

the lighting technology (PiandLoi) and on daylight

and solar gains (TV and TT). This result and thethree others given by the above formulas illustratethe reality of the interaction between lighting andHVAC systems.

We note that the orientation is not among theselected parameters. Indeed, in the general case, itsinfluence is so important that it must be consideredas a data of the simulation. In the previous example,we have a particular case since it is a square-shapedoffice with peripherals offices where the orientationdoes not intervene on annual energy needs.


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Figure 1 Comparison between simulated annual energy needs

with CA-SIS + LIGHT and those calculated by energy formulas

(with confidence interval)

We have tested the validity of the previousrelations (1), by comparison of the results theygive and those calculated with CA-SIS + LIGHT,on a large office building different from that used

in the example described above (=reference) butwhere orientation has again no influence (peripheraloffices on rectangular shaped floors with shaperatio of 0.75). The values of annual energy needsobtained by the previous relations must be corrected

by the volume ratio (=0.71) between the tested officebuilding and the reference one (=example).

The results of the comparison are given byFigure 1. By taking into account the confidenceinterval applied on values calculated by energyformulas, the comparison is very good. Then, the

relations (1) are good tools to quickly evaluateannual energy needs for a large office buildingwhose shape is near a square and where orientationhas no influence. Designers can study the sensibilityof these results to the values of characteristic

parameters and choose the better solution.

3. Simulation of the interaction between lightingand HVAC system

3.1 Basic principlesStudy of the interaction between lighting and

thermal loads requires to carefully quantify boththe electric/ natural light coupling, and the electriclight/ thermal loads interaction. This can be donethrough the computer code CA-SIS, able to achievetransient thermal simulations [11]. This code has

been completed by the light module called LIGHT.

Figure 2Diagram of interaction between thermal and luminous

behavior

The thermal behavior computed by CA-SISdepends on the respective parts of convective andradiative fluxes of each entity producing thermalloads. The thermal effects generated by electriclighting are either of convective or radiative nature.

The proportion of each component depends both onthe light source (incandescent or fluorescent) andon the kind of installation (hanging or embeddedlamp). The thermal loads on ambient air due toelectric lighting are purely of convective nature.Between instantaneous radiative thermal effectsand thermal loads, there is a delay more or lessimportant, depending on the thermal inertia. Thesame phenomena exists for all the type of thermalloads inside the buildings, because their thermaleffects always contain a radiative part (long wave

radiation by occupants, processes and mutual wallradiation or short wave radiation as solar gains andelectric lighting). The thermal inertia has a largeinfluence on thermal comfort, but it does not muchinterfere on energy consumption for a long period asshown in the previous paragraph.

To take into account the lighting thermalloads, a continuous dialogue between thermal andluminous behavior must be established, as shown onFigure 2.

The interaction between lighting and airconditioning arises both from the thermal loadsgenerated by the electric lighting and from theeffect of the blinds, which impacts on natural lightavailability and solar gains.

3.2 Lighting calculationsTo calculate the thermal loads of electric lighting

which complete daylight, an illuminance level isassigned [12].


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When daylight illuminance is below this settinglevel, two possibilities exist according to theefficiency of the control device:- the basic lighting control device which contains

only a clock and a presence detector switches onall or a part of - the electric lighting equipmentat the maximal power if the conditions of

starting are carried out;- the intelligent lighting control device, whichhave in addition a servo control and a powergradation, fixes the necessary amount of electriclight just complementary to daylight and therequired power is produced (see Figure 3).

Figure 3Complementarity between daylight and electric lighting

The power of the electric lighting equipmentwhich is called out gives convective and radiativeinstantaneous gains. They have respectively a directand an indirect delayed influence on sensible energy

balance of the building. If the amount of availabledaylight equals or exceeds the setting level, thenthere is no extra thermal loads due to electriclighting.

The daylight illuminance on the working planecan be considered as the resultant value of threeshort wave radiation fluxes: diffuse flux from thesky, direct flux from the sun and flux from insideand outside reflections.

The inside illuminance Eintj

is calculated at thecentre of each zone j of the working plane which isdivided in nine zones (Figure 4) The value whichis compared with the setting value is the averageof these punctual illuminances, excepted these ofthe zones near the windows (white zones in theFigure 4).

The calculations achieved by LIGHT every hourfollow five steps: estimation of daylight outside diffuse horizontal

illuminance; estimation of the diffuse component of internal

illuminance; reduction of the diffuse component due to

shading; estimation of the internal direct and diffuse

reflected component; estimation of daylight inside illuminance.

3.2.1 Sky diffuse component of the daylight(outside and inside a building)

The current meteorological data of the solarradiation concern direct and diffuse irradiances (inW.m-2). To convert these energy data in luminousdata, we have used luminous efficiency model ofPerez [13] or Perraudeau [14] and the associatedclassification of the skies. These two authors havedefined respectively 7 and 5 types of sky (fromclear to overcast) by using air temperature, airhumidity and respectively the correlation betweendiffuse irradiance and global irradiance (measuredmeteorological data) established by Reindl [15]or by Orgill and Hollands [16]. The Franzettis

procedure [1] gives a correspondence between thesetwo classifications. Each type of sky is characterised

by a specific luminance pattern which allows thecalculation of outside diffuse illuminances on any

plane.Inside the buildings, the illminances at any point

Figure 4Description of the working plane partition


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of the working plane due to the sky is evaluated byusing the notion of Extended Daylight Factors. Wehave developed this concept for each type of sky bytaking into account their sky luminance pattern. Thishypothesis is consistent with the results obtained byDumortier [6].

The sky diffuse component (Eintd

) at a point (or a

zone) of the working plane can be expressed by thesum of the contributions of each part of the sky seenthrough meshes of the windows resulting from anadapted partition:

whereFJDis the extended daylight factor; a1, a

2are

parameters which depend on the type of sky [17]according to the classification proposed by Rerez orPerraudeau, and on the diffuse light transmission rate

(d) of the glass used as reference in the calculations; is a function of the geometry of the luminousexchange between the window mesh and the zone;

Eextd

is the outside horizontal diffuse illuminance;Ls is the relative mean luminance of the sky seenthrough a part of the window (value of the meanluminance divided byE

extd).

3.2.2 Reduction of the sky diffuse component dueto shading

The diffuse component can be reduced by thepresence of outside obstacles shading the sky to thewindows, narrow screens (balconies, loggia walls,sun screens) and blinds.

The reduction of the diffuse component byoutside obstacles is taken into account in cancellingthe value of FJD corresponding to the parts ofshaded sky.

The reduction ratio (m) of the diffuse component

by outside narrow screens is a function of geometriccharacteristics of the parts which shade the sky tothe windows.

The reduction ratio (p) of the diffuse component

by a blind is a function of percentage of the windowsobstructed.

The corrected extended daylight factor, whichtakes the place of FJD in the formula (2), isexpressed by [18]:

where is a lump overvaluation (about 10% for

clear environment) to rough estimate the influenceof the reflection of the light by the narrow obstaclesand screens.

3.2.3 Internal diffuse reflected componentThe inside parts of the walls of the room are

supposed to be perfectly diffusive and obey to the

Lamberts law. Their average reflected rate is noted

m. The internal reflected component is a function of

this rate and of the sky diffuse component on a zoneof the working plane [1]:

where ddepends on the geometry of the room.

3.2.4 Solar componentThe sunlight generates two sources: the first

one is the solar spot, the second one is an insidehomogeneous flux of reflected light.

The purpose of LIGHT is to calculate the electriclighting necessary to complete daylight. As onlymean illumination is taken into account; the solarspot is excluded because it generates high and verylocalised levels of illuminance, not representative ofwhat is effective on the working plane.

Consequently, the solar component can beexpressed only as the inside diffuse illuminance dueto the direct solar flux entering the room throughthe window and reflected by the inside parts of thewall [1]:

where Sw/Stis the ratio of windows area to the areaof all the opaque inside parts of the room; Esv isthe direct solar vertical illuminance on the windows,when it exists (if not, it is equal to zero) and possiblycorrected if shading by a blind is effective at thecalculation time;

D is the direct light transmission

rate of the reference glass, depending on incidenceangle of the solar radiation on the windows.

3.2.5 Final value of illuminance of the workingplane

For a zone j of the working plane, the horizontalilluminance Eint

j is given by the following

expression:

where dand

Dare correction factors to take into

account the true properties of light transmission (d:diffuse and D: direct) of the glass of the windows, in

(2)

(3)

(4)

(5)

(6)


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place of the properties of the glass used as referencein the calculations.

3.3 Experimental validation of lightAn experimental study has been realised in a

laboratory (Figure 5) to compare the measured valueof daylight illuminance level on the working plane

and the value estimated by LIGHT [19].The laboratory is located in the Research Centreof EDF (Les Renardires). It is in accordance with

the prescriptions of the IEAs Task 21 [20]. Globaland diffuse outside illuminances are measuredwith a LMT illuminance meter. Global and diffuseirradiances are measured with a KIPP and ZONEN

pyrometer. In the laboratory, illuminance meterscontrol the illumination level on the working planeand on other characteristic points.

The results of this experimental study areillustrated on the Figures 6 and 7. On the first figure,the comparison between the calculated and the

Figure 5Laboratory and inside points of illuminance measures

Figure 6Comparison between calculated and measured values for diffuse outside horizontal illuminance

Figure 7Comparison between calculated and measured values for diffuse working plane illuminance

Calculated diffuse outside horizontal illuminance (lux)

Measured diffuse outside horizontal illuminance


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measured values of the diffuse outside horizontalilluminanceE

extdis very good and proof the validity

of the luminous efficacy Perezs model, except forvery small values which correspond to low values ofsun height (


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building. The Figure 8 shows what can be predictedfor an office building as regards the influence of thelighting devices and of the kind of window.

The new French thermal regulation imposesa limit for the power of the lighting devices at16 W/m in an office building. In this application,thanks to a more efficient installation (only 9 W/m)

the lighting energy consumption is reduced, but theenergy heating needs increase (Figure 8,solution 1and 3).

The choice of an efficient lighting control deviceis favorable on lighting energy consumption andalso on global energy needs, but again the energyheating needs increase a little in this case (Figure 8,

solution 2 and 3).A drastic reduction of the relative aperture rate

TVby a factor 6 (for example by reducing windowsarea and light transmission rate) leads to heatingand global energy saving of about 50%, but lighting

energy consumption is 25% up (Figure 8, solution4 and 5).The choice of an efficient lighting device is very

sensitive on the lighting annual energy consumption.But the choice of the relative aperture rate TV is amore sensitive parameter on the global energy needsof an office building.

The Figure 8 illustrates the fact that thetechnological choices have to be made in agreementwith the architectural choices for a better energydesign.

4.2 Daylight developmentThe reference building described in theparagraph 2 has been tested in two situations:the first corresponds to a fictitious one where nodaylight is available and in the second daylightis effective. In both cases, the office building is

located at Trappes (Hi=+1), the power of electriclighting installation is 12 W.m-2 (efficient lightingequipment), the lighting control device is of clock-type, the illuminance setting level is 425 lx on theworking plane and a reverse thermodynamic system

provides air conditioning with a COP of 1.5 (annualmean value). In the first situation, lighting is only

electric and windows are fictitiously considered ashaving only a thermal influence, when they havein addition a luminous and visual influence in thesecond situation. They are double glazing windowswith a light transmission rate equals to 0.82.

The annual energy needs obtained with CA-SIS+ LIGHT in the two situations are given in Figure9. It shows that without daylight, the cooling needsare more important than the heating needs. Coolingis used to evacuate the internal loads, which aremainly due to lighting in the hot period.

This implies a large reduction of all energyneeds (except heating needs) when daylight is usedeven by a basic light control device.

The daylight availability according to theorientation of the offices of the reference building isshown by Figure 10. The switch on periods of electriclighting devices along the year, which is a sort ofcomplementary measure of the daylight availability,vary a lot with orientation and season. In Trappes

but in numerous places too, south orientation is themost interesting for the developement of daylight.

5. Conclusions

This work illustrates the importance of takinginto account the interaction between lighting andHVAC system. This notion is useful to understand

Figure 9 Annual energyneeds [kWh]


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and foresee the energy needs of office buildings.

The new French thermal regulation [21] makesthis subject more sensitive. At the present time, theaim is to improve the thermal performances of newoffice buildings by 25%. The global reflection abouttechnological and architectural design is important tosucceed in a consistent approach of Energy DemandSave Management. For example, the choice of someexpansive light control device must be justified bylarge reduction of energy consumption, not only forlighting but also for global consumption includingheating and cooling too.

The next step of this work will be thegeneralisation of the simplified energy formulas toother buildings with regards to their architectural

properties and their activities. This task will be madeeasier thanks to the new software LIGHT allowingto include the natural and electric light in thermalenergybalance computed by the code CA-SIS or byothers thermal codes. Some other validation worksmust be still carried out to increase confidence inthis tool, in particular for a better control of visualcomfort (glare control, luminance balance, )

which must be always associated to a goal of energysaving.

6. References

1. Franzetti, C., 2001, Etude de linfluence de lacomplmentarit entre lclairage naturel etlclairage artificiel sur le comportement thermique

des btiments tertiaires, Thse Universit de Savoie,

March2. DAlfonso, 1996, Larchitecture: les formes et les

styles, de lantiquit nos jours, Ed. SOLAR3. Fontoynont, M., Place, W., Bauman, F., 1984, Impact

of Electric Lighting Efficiency on the Energy SavingPotential od Daylighting from Roof Monitors,

Energy and Buildings, vol. 6, 375 3864. *** , 1996, Delta, a blind controller using fuzzy

logic, OFEN/BEN funding nr. 50943 Final Report,Laboratoire dEnergie Solaire, EPFL, Lausanne,

November

5. Hartmann, O., Cordier, H., Franzetti, C., Leonard,J.C., 2000, Exemples dutilisation du logiciel dethermique du btiment CA-SIS,IBPSA 2000, SophiaAntipolis, October

6. Dumortier, D., 1995,Mesure, analyse et modlisationdu gisement lumineux. Application lvaluation des

performances de lclairage naturel des btiments.Thse Universit de Savoie, December

7. TRNSYS, A Transient Simulation Program, version14.2, Reference manuel, Solar Energy Laboratory,University of Wisconsin, Madison, USA

8. Pillet, M., 1997, Les plans dexprience par lamthode de taguchi, Editions dorganisation, Paris

9. UMETRICS, Description du logiciel MODDE,fonctions et littrature associe, http://www.umetrics.com

10. Teneehaus, M., 1998, La rgression PLS: thorie etpratique, Edition Technip

11. Roldan, A., 1985,Etude thermique et araulique des

Figure 10 Switch on periods of the electric lighting devices


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enveloppes de btiments. Influence des couplagesintrieurs et du multi-zonage, Thse INSA de Lyon,December

12. * * * , 1993,Recommandations relatives lclairagedes locaux de travail, Edition LUX, AFE Paris

13. Perez, R., Seals, R., Michalsky, J., 1993, All weathermodel for sky luminance distribution, preliminary

configuration and validation, Solar Energy, vol. 50,nr. 3

14. Perraudeau, M., 1986, Climat lumineux Nantes,rsultats de 15 mois de mesures, CSTB, EN-ECL86.141 Report

15. Reindl, D. T., Duffie, J. A., Beckman, W. A., 1990,Diffuse fraction correlations, Solar Energy, vol. 45,nr. 1, 1-7

16. Perraudeau, M., 1990, Daylight availability fromenergetic data, CIE Moscou, vol. 1/A17

17. Perraudeau, M., 1998, Modlisation de lclairage

naturel dans CA-SIS, EN-ECL 98.9.C TechnicalReport18. Achard, G., Franzetti, C., Binesti, D., 2001, Etude

de linfluence de lclairage naturel et artificielsur les besoins nergtiques globaux des btimentstertiaires, Vme Colloque interuniversitaire franco-quebecois, Lyon, 28 30 May, 463 470

19. Franzetti, C., Achard, G., Binesti, D., 2000,Simulation du besoin nergtique global desbtiments: modlisation et validation exprimentalede la pntration de la lumire naturelle, IBPSA2000 Proceedings, Sophia Antipolis, October

20. International Energy Agency, 1998, Monitoringprocedures for the assessment of daylighting.Performance of buildings, Task 21/A-2/DK: 96-11

21. Visier, J. C., Scwach, P., Herant, P., Farkh, S., Zirngibl,J., Millet, J. R., David, L., 2000, Rglementationthermique 2000, CSTB magazine, December, 3 - 29

Received 10 July 2004Reviewers Dr. David CARTER,Prof. Marc FONTOYNONT, Prof. Koichi IKEDA

Dr. Eng. Christelle FRANZETTI, Electricit de France,DCPE/Tertiel/REEL196 avenue Thiers 69461 Lyon Cedex 06 Francee-Mail: [email protected]

Dr. Gilles FRAISSE, Laboratoire Optimisation de laConception et Ingnierie de lEnvironnement, EcoleSuprieure dIngnieurs de Chambry, Universit deSavoie73376 le Bourget du Lac Cedex, FranceTel.: (33) 479 75 88 95; Fax: (33) 479 75 81 44e-Mail: [email protected]

Ass. Eng. Oana DOBRE,Laboratoire Optimisation dela Conception et Ingnierie delEnvironnement, Ecole SuprieuredIngnieurs de Chambry,Universit de Savoie73376 le Bourget du Lac Cedex,FranceTel.: (33) 609 84 31 16e-Mail: [email protected]

Prof Gilbert ACHARD,LaboratoireOptimisation de la Conception etIngnierie de lEnvironnement,Ecole Suprieure dIngnieurs deChambry, Universit de Savoie73376 le Bourget du Lac Cedex,FranceTel.: (33) 479 75 88 18;Fax: (33) 479 75 81 44e-Mail: [email protected]


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INFLUENA LUMINII NATURALE I A ILUMINATULUI ELECTRICSUPLIMENTAR ASUPRA NEVOII ENERGETICE DIN CLDIRILE DE

BIROURI

Lumina natural i cea electric sunt complementare i aceast asociere trebuie s fie luat nconsiderare n analiza nevoii energetice globale din cldirile de birouri datorit sarcinilor termice

generate de iluminatul electric i a influenei ferestrelor asupra att a comportamentului luminos, cti a celui termic al ncperilor. Acest articol trateaz bilanul energetic prevzut pentru o cldire debirouri cu referire la soluii tehnologice i de arhitectur. O analiz global este necesar pentru un

studiu coerent al Managementului de Economie a Cererii de Energie.

1. Introducere

Se presupune n general c aproape 30% dinconsumul energetic al cldirilor de birouri este

datorat iluminatului electric. n scopul reduceriiacestui consum de energie, fabricanii propun ovarietate de sisteme de control care adapteazcantitatea de lumin electric n funcie de aportulde lumin natural ntr-o ncpere, meninnd unnivel minim de iluminare necesar desfurrii uneiactiviti i a realizrii confortului vizual. Acestesisteme sunt indicate pentru o reducere de 65%,n cele mai bune cazuri, a consumului energeticelectric datorat iluminatului. Oricum, interaciuneade energie dintre iluminat i climatizare trebuie sfie luat n considerare n etapele de management deeconomie al cerinei de energie. Degajarea de cldur

produs de iluminatul electric constitue un efectbenefic n perioadele de iarn prin reducerea nevoiide nclzire, dar ea crete cererea de climatizare n

perioadele de iarn.Mai multe soluii tehnologice sau arhitecturale

pot fi utilizate n scopul valorizrii i controluluiluminii naturale [2]. Consumul de energie electricdatorat iluminatului este legat de momentul punerii

n funciune a acestuia. Reducerea consumului deenergie electric poate fi realizat prin alegereaunei instalaii eficiente sau a unui control mai bunal timpului de utilizare. Aceasta poate fi realizatcu ajutorul noilor tehnologii de iluminat. Pentru aatinge acest scop putem utiliza complementaritateadintre iluminatul natural i cel electric.

n perspectiva proteciei mediului nconjurtor,nevoia de energie n cldiri trebuie s fie luat nconsiderare de manier global [3]. Interaciuneadintre iluminat i climatizare moduleaz evaluarea

avantajului de energie consumat de iluminat.Scopul lucrrii este de a identifica i a precizaparametrii fenomenelor de interaciune pentru aghida utilizatorii spre o alegere a tehnologiilor decontrol al iluminatului i al design-ului arhitectural.

2. Comportament luminos i termic ntr-o cldirede birouri

Pentru a studia avantajul modulrii energiei globaledatorate dispozitivelor inteligente de control deiluminat care se bazeaz pe complementaritateadintre iluminatul electric i cel natural, au fostconsiderai mai muli parametri ca: arhitecturacldirii, mediul nconjurtor al cldirii, materialeleimplicate, tehnologiile implicate, activitiledesfurate i confortul ocupanilor.

S-au selecionat 14 parametri (vezi Tabel 1) carefac referire la analizele precedente de sensibilitate,considerai a fi cei mai caracteristici.

Simulrile au fost conduse cu ajutorul unui

program de calcul dezvoltat de EDF (Regia Francezde Energie) numit CA-SIS [5]. Acest program

permite o estimare a diferitelor nevoi n energie(iluminat, nclzire, climatizare i global) a cldirilorde birouri. Comportamentul termic al cldirii estesimulat cu ajutorul programului de calcul TRNSYS[7], iar comportamentul luminos este evaluat cu


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ajutorul unui program de calcul specific dezvoltatde noi numit LIGHT. Acest program ine seamade iluminatul electric care completeaz, dac estenecesar, pe cel natural.

Iluminarea dat de lumina natural pe planul utileste obinut prin nsumarea a trei componente carein de distribuia de luminan a cerului (componentadirect, componenta reflectat extern i componentareflectat intern) i de componenta reflectatintern a emisiei solare directe. Aceast ultimrestricie corespunde unui bun design al faadei,

permind realizarea iluminrii directe de la soarepe planul util. Studiul comportamentului luminos alcldirilor de birouri cu ajutorul programului LIGHTd rezultate bune (10%) pentru o valoare medie ailuminrii pe planul util de 1000 lx (vezi paragraf3.3). Peste aceast valoare, probabilitatea existenei

orbirii este suficient de mare, ceea ce implicutilizarea unei protecii vizuale pentru a reduceluminana ferestrelor la o valoare adecvat. n acestcaz, presupunem c iluminarea dat de luminanatural este mereu suficient. Deci, n consecin,diminuarea cantitii de lumin natural datoritnnorrilor este doar o diminuare a comportamentuluitermic dat de reducerea transmiterii de energieradiant prin ferestre.

Interaciunile dintre iluminatul natural i cel

electric i procesul HVAC pot fi evaluate prinrelaiile existente ntre nevoile n energie cerute deiluminat i de parametrii cei mai eficieni dai nTabelul 1.

S-a ales metoda planului experimental [8]pentru a reduce numrul simulrilor necesare pentrua obine relaiile descrise mai sus.

Pentru fiecare parametru, se definete un nivelmaxim i un nivel minim, alese pentru a reprezentacldirile de birouri actualizate din Frana.

Cu ajutorul unei proceduri de ecranare[9], se selecioneaz parametrii cei mai eficieni.Mulumit tratamentului statistic [10] importanafiecrui parametru poate fi estimat ntr-un intervalde eroare. Ca exemplu, se prezint rezultatele uneicldiri de birouri de seciune ptrat i avnd 7 etaje(caz de referin pentru ce urmeaz). Suprafaa totala celor 7 etaje este de 2800 m2. Toate birourile sunt

plasate la periferia fiecrui etaj, iar zonele comunesunt plasate n centrul cldirii.

Procedura de ecranare d un plan fracionalpentru 65 experiene, comparat cu 214 sau 16.384experiene dat cu ajutorul planului completcorespunztor a 14 parametri i 12 niveluri (min imax).

Diferite relaii dintre parametrii cei mai eficieni(vezi Tabelul 1) i interaciunile de primul rang cuconsumul energetic anual al iluminatului sau altenevoi energetice anuale (nclzire, climatizare,nevoi energetice globale) vor fi realizate aplicndmetoda planului de experien. Acesta corespundeformulelor urmtoare pentru care rezultatele sunt nGWh iar parametri extensivi (Pi, TV, TT) corespundla valoarea redus care variaza ntre 0 i +1, relativn intervalul de variaie formula (1).

Datele simulrii sunt:- temperatura cerut pentru nclzire: 20 C

n perioadele ocupate i 12 C n perioadeleneocupate;

- temperatura cerut pentru climatizare: 24 Cn perioadele ocupate i 28 C n perioadeleneocupate;

- nivelul de iluminare cerut pe planul de lucru:500 lx.

Nevoile energetice globale depind n special de

tehnologia iluminatului (Pi i Loi) i de aporturilesolare i n lumin natural (TVi TT). Acest rezultati nc trei altele obinute cu ajutorul relaiilor de maisus ilustreaz realitatea interaciunii dintre iluminati sistemul HVAC.

Se noteaz c orientarea nu se afl printreparametrii alei. De altfel, n cazul general, influenaorientrii este suficient de importan pentru a filuat n considerare ca o dat a simulrii. Exemplul

precedent reprezint un caz particular deoarececldirea de birouri este de seciune ptrat cu birouri

periferice pentru care orientarea nu intervine nnevoile energetice anuale.

S-a testat validitatea relaiilor precedente (1)prin compararea rezultatelor obinute cu celecalculate cu ajutorul CA-SIS+LIGHT, pentru ocldire spaioas de birouri, diferit de cea utilizatn exemplul descris mai sus (= de referin) i pentru


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care orientarea nu influeneaz (birourile perifericedin suprafaa dreptunghiular pe un etaj caracterizatde un factor de form de 0,75). Valorile nevoilorenergetice anuale obinute cu formulele precedentetrebuie corectate cu un coeficient volumic (0,71)existent ntre cldirea de birouri testat i cea dereferin (= exemplu).

Rezultatele comparrii sunt date n Figura 1.Lund n considerare intervalul de eroare aplicatvalorilor calculate cu formulele de energie,compararea este foarte bun. Astfel, relaiile (1)sunt foarte utile n cazul evalurii rapide a nevoilorenergetice anuale pentru cldirile spaioase de

birouri de seciune apropiat de cea ptrat i pentrucare orientarea nu intr n calcul. Conceptorii potstudia precizia acestor rezultate n funcie de valorile

parametrilor caracteristici n alegerea unei soluii

mai bune.

3. Simularea interaciunii dintre iluminat isistemul HVAC

3.1 Principii de bazStudiul interaciunii dintre iluminat i sarcinile

termice este necesar att n asocierea dintre iluminatulelectric i cel natural ct i n cea dintre iluminatulelectric i interaciunea sarcinilor termice. Aceasta

poate fi realizat cu ajutorul programului de calculCA-SIS, capabil s construiasc simulri termicetemporale [11]. Acest program poate fi completat

printr-un modul de iluminat numit LIGHT.Comportamentul termic simulat cu CA-SIS

depinde, n parte, de fluxurile radiative i convectiveale fiecrui element generator de sarcini termice.Ponderea fiecrui element depinde att de sursade lumin (incandescent sau fluorescent) ct ide tipul instalaiei (aparat de iluminat suspendatsau ncastrat). Sarcinile termice n mediul interioral ncperilor provocate de iluminatul electric suntde natur pur convectiv. ntre efectele termiceradiative instantanee i sarcinile termice exist ontrziere mai mare sau mai mic care depinde deineria termic. Acelai fenomen exist pentru toatetipurile de sarcini termice dintr-o cldire, deoareceefectele termice ale acestora conin mereu o parte

radiativ (radiaii de lungime de und lung datorateocupanilor, radiaii de proces i de interaciune cu

pereii sau radiaii de lungime de und scurt caaporturile solare i cele de iluminat electric). Ineriatermic are o mare influen asupra confortuluitermic, dar ea nu intervine n consumul energeticdin perioadele lungi de timp, cum este artat n

paragraful precedent.Pentru a ine cont de sarcinile termice provocate

de iluminat trebuie stabilit un dialog continuu ntrecomportamentul termic i cel luminos, cum esteartat n Figura 2.

Interaciunea dintre iluminat i climatizarerezult att din sarcinile termice generate deiluminatul electric ct i din efectul storurilor, caimpact asupra disponibilitii de lumin natural ia aporturilor solare.

3.2 Calcul de iluminatPentru a calcula sarcinile termice i iluminatul

electric care-l completeaz pe cel natural estenecesar alegerea unui nivel de iluminare [12]. Cndiluminarea datorat luminii naturale este sub nivelulales exista dou posibiliti care sunt n concordancu eficiena dispozitivelor de control:- dispozitiv de control de baza al iluminatului

care nu conine dect un ceas i un detector de

prezen pus n funciune mereu sau intermitent,cnd echipamentul de iluminat electric areputerea maxim, dac condiiile de funcionaresunt ndeplinite;

- dispozitiv inteligent de control al iluminatuluiavnd n plus un server de control i o gradaren uniti de putere, care fixeaz cantitateanecesar de lumin electric complementarcu lumina natural cnd puterea cerut este

produs (vezi Figura 3).Puterea echipamentului de iluminat electric

cerut realizeaz ctiguri instantanee radiativei convective. El prezint o ntrziere direct iindirect care influeneaz precizia bilanuluienergetic al cldirii. Dac cantitatea de luminnatural disponibil este egal sau excede niveluluifixat, atunci nu mai exist sarcini termice externedatorate iluminatului electric.


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Iluminarea datorat luminii naturale pe planulutil poate fi considerat ca o valoare rezultant dincele trei fluxuri de lungime de und scurt: fluxdifuz de la cer, flux direct de la soare i flux datoratreflexiilor interne i externe.

Iluminarea interioar Eint este calculat ncentrul fiecrei zoneja planului util divizat n nouzone (Figura 4). Valoarea care este comparat cu ceafixat este dat de media acestor iluminri punctuale,exceptnd cea a zonelor din proximitatea ferestrelor(zonele albe din Figura 4).

Calculele realizate cu ajutorul programului decalcul LIGHT n fiecare or urmresc patru etape:

estimarea iluminrii orizontale difuzeexterioare date de lumina natural;

estimarea componentei difuze a iluminriiinterne;

reducerea componentei difuze datorateumbririi;

estimarea componentei directe interne i acelei reflectate difuze;

estimarea iluminarii interne date de luminanatural.

3.2.1 Componenta difuz a luminii naturaleprovenite de la cer (extern sau intern uneicldiri)

Datele meteorologice actuale despre radiaiasolar se refer la radiaiile difuze i cele directe (nW.m-2). Pentru a converti aceste date energetice ndate luminoase, s-a utilizat modelul de eficacitateluminoas Perez [13] sau Perraudeau [14] iclasificarea care rezult a cerurilor. Aceti autori audefinit 7 i respectiv 5 tipuri de cer (de la clar laacoperit) utiliznd temperatura aerului, umiditateaaerului i respectiv corelaia dintre emitana difuzi cea global (date meteorologice msurate)stabilite de Reindl [15] sau de Orgill i Hollands[16]. Procedura lui Franzetti [1] d corespondenadintre aceste dou clasificari. Fiecare tip de cer estecaracterizat de un model specific de luminan care

permite calcularea iluminrilor difuze exterioare peorice plan.

n interiorul cldirilor, iluminrile n oricepunct din planul util provocate de cer sunt

calculate utiliznd noiunea de Factor de luminnatural excedent. S-a dezvoltat acest concept

pentru fiecare tip de cer innd cont de modelul deluminan a cerului. Aceast ipoteza este n corelaiecu rezultatele obinute de Dumortier [6].

Componenta difuz a cerului (Eintd

) ntr-unpunct (sau dintr-o zon) din planul util poate fi datde suma contribuiilor fiecarei pri de cer vzut

prin ochiurile de fereastr rezultat ca o divizareadaptat relaia (2) unde FJD este factorul deexcedent de lumin natural; a

1, a

2sunt parametri

care depind de tipul de cer [16] n concordan cuclasificarea propus de Rerez sau Perraudeau i decoeficientul de transmisie al luminii difuze (

d) al

geamului utilizat ca referin n acest calcul; esteo funcie geometric a transferului luminos ntreochiurile de fereastr i zon; E

extd este iluminarea

difuz orizontal exterioar; Ls este luminanamedie relativ a cerului vzut prin fereastr (valoarerezultat din divizarea luminanei medii prinE

extd).

3.2.2 Reducerea componentei difuze a ceruluidatorit umbririi

Componenta difuz poate fi redus prin prezenaunor obstacole exterioare care umbresc cerul vzut

prin fereastr sau prin ecrane subiri (balcoane,geamuri solare) sau storuri.

Reducerea componentei difuze prin suprapunereaunor obstacole exterioare este luat n consideraren anularea valorii luiFJDcorespunztoare a priiumbrite de cer.

Factorul de reducere (m) al componentei difuze

rezultate prin prezena ecranelor subiri este ofuncie de caracteristicile geometrice ale prilorcare umbresc cerul vzut prin fereastr.

Factorul de reducere (p) al componentei difuze

datorat storurilor este o funcie de procente dinsuprafaa ferestrei obturate.

Factorul de excedent de lumin natural corectatcare nlocuieteFJDn relaia (2) este dat n [19] relaia (3) unde aeste supraevaluarea obstacolului(aproape 10% din mediul nconjurtor liber) careajut la estimarea dificil a influenei reflexiei luminii

pe obstacolele apropiate de geamul ferestrei.


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3.2.3 Componenta reflectat difuz internSe presupune c partea interioar a pereilor

ncperii este perfect difuzant i respect legealui Lambert. Coeficientul lor de reflexie mediu estenotat

m. Componenta reflectat intern este funcie

de acest coeficient i de componenta difuz a ceruluipe o zon din planul util [1] relaia (4) unde ddepinde de geometria ncperii.

3.2.4 Componenta solarLumina natural genereaz dou surse: prima

este spotul luminos, a doua este un flux omogeninterior de lumin reflectat.

Scopul programului de calcul LIGHT este de acalcula iluminatul electric necesar pentru a completalumina natural. Cum este luat n considerare doariluminarea medie, spotul solar este exclus deoarece

el genereaz un nivel de iluminare foarte nalt ifoarte localizat, nereprezentativ fa de ce se gseteefectiv pe planul util.

n consecin, componenta solar poate fiexprimat doar prin iluminarea difuz interioardatorat fluxului solar direct care intr n ncpere

pe fereastr i a celui reflectat de partea interioara pereilor [1] relaia (5), unde Sw/St este factorulde suprafa de fereastr n funcie de suprafaatuturor pereilor opaci interiori ai ncperii,Esv este

iluminarea vertical direct solar pe fereastr cndaceasta exist (dac nu, ea este nul) i corectatdac umbrirea provocat de un stor este efectiv ntimpul calculului;

Deste coeficientul de transmisie

de lumin direct a geamului de referin, caredepinde de unghiul de inciden al radiaiei solare

pe fereastr.

3.2.5 Valoarea final a iluminrii pe planul utilPentru o zon j a planului util, iluminarea

orizontalEintjeste dat de relaia (6), unde

di

D

sunt coeficieni de corecie care trebuie s fie luain seam n proporii reale de transmisie a luminii(d: difuzat i D: direct) a geamului ferestrei nlocul proporiilor de geam utilizate ca referin ncalcule.

3.3 Validarea experimental a luminiiUn studiu experimental a fost realizat n laborator

(Figura 5) pentru a compara valoarea msurata nivelului de iluminare dat de lumina natural

pe planul util cu valoarea estimat cu ajutorulprogramului de calcul LIGHT [19].

Laboratorul este plasat n Centrul de cercetareal EDF (Les Renardires). El este n concordan cu

principiile lui IEAs Task 21 [20]. Iluminrile difuzi global extern sunt msurate cu un luxmetruLMT. Emitanele difuz i global sunt msuratecu un pirometru tip KIPP i ZONEN. n laboratorluxmetrul controleaz nivelul de iluminare pe planulutil i n alte puncte caracteristice.

Rezultatele acestui studiu experimental suntilustrate n Figurile 6 i 7. n prima figur,E

extdeste

foarte bun i valideaz eficacitatea luminoas a

modelului Perez, cu excepia valorilor foarte micicare corespund unei poziii joase a soarelui (


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spaioase cu birouri periferice i etaje de seciuneptrat sau birouri nchise). Aceast prim aplicaieilustreaz realitatea interaciunii dintre iluminati sistemul HVAC i arat c nevoile energeticeglobale depind de tehnologia de iluminat i deaporturile solare de lumin natural. Prezentmacum alte dou aplicaii ale asocierii dintre CA-SISi LIGHT.

4.1 Influena aparatelor de iluminat i aferestrelor

S considerm o cldire de birouri de 5000 m2.n prima etap din realizarea unui proiect, arhiteciii inginerii trebuie s fac cteva alegeri tehnologicei arhitecturale cruciale.

De exemplu, noua reglementare termic francez[21] incit s se ia n considerare nevoile energetice

estimate ale cldirii proiectate pentru a limita efectulemisiei de gaze.

Asocierea dintre CA-SIS i LIGHT permiteprevederea consecinelor alegerilor arhitecilor iinginerilor asupra nevoilor energetice ale cldirii

proiectate. Figura 8 arat ce poate fi ales pentruo cldire de birouri care ine seama de influenaaparatelor de iluminat i de tipul de fereastrutilizat. Noua reglementare termic impune olimitare a puterii instalate a aparatelor de iluminat la

16 W/m2

ntr-o cldire de birouri. n aceastaplicaie, mulumit unei instalaii mai eficiente(doar 9 W/m2), consumul energetic al iluminatuluieste redus, ns nevoile energetice pentru nclzirecresc (Figura 8, soluia 1 i soluia 3).

Alegerea unui dispozitiv eficient de control aliluminatului este favorabil n consumul energetical iluminatului i, de altfel, n nevoile energeticeglobale, dar sub nivelul nevoilor energetice pentrunclzire care scad n acest caz (Figura 8, soluiile2 i 3).

O reducere drastica a factorului de mrimerelativ TV de aproape 6 ori (de exemplu, prinreducerea suprafeei ferestrelor i a coeficientului detransmisie al ferestrelor) conduce la o economie deenergie pentru nclzire i global de aproape 50%,dar, n schimb, consumul energetic pentru iluminateste cu 25% mai mare (Figura 8, soluiile 4 i 5).

Alegerea unui aparat de iluminat mai eficientare un impact puternic asupra consumul energeticanual pentru iluminat. Dar alegerea unui coeficientde mrime relativ TV este mai puin resimit nanaliza nevoilor energetice globale ale cldirilor de

birouri.Figura 8 ilustreaz faptul c alegerile tehnologice

trebuie s fie fcute n concordan cu alegerilearhitecturale pentru un proiect energetic mai bun.

4.2 Valorizarea luminii naturaleCldirea de referin descris n par. 2 a fost

testat n dou situaii: prima corespunde la o situaiefictiv cnd nu exist lumin natural, a doua cndexist lumin natural. n ambele cazuri, cldireade birouri este plasat n Trappes (H

i=+1), puterea

specific a instalaiei de iluminat electric este de 12

W/m2 (aparat de iluminat eficient), dispozitivul decontrol al iluminatului este temporizat, nivelul deiluminare este fixat la 425 lx pe planul de lucru iun sistem termodinamic de rezerv asigur aerulcondiionat cu un COP(coeficient de performan)de 1,5 (valoare medie anual).

n prima situaie iluminatul este doar de tipelectric i se consider c ferestrele au doar oinfluen termic, comparativ cu situatia a doua,cnd ele au i o influen vizual i luminoas.

Ferestrele sunt duble cu un coeficient de transmisiea luminii de 0,82.Nevoile energetice anuale obinute cu CA-SIS

i LIGHT n ambele situaii sunt date n Figura9. Se arat c fr valorizarea luminii naturale,nevoile n climatizare sunt mai importante dectcele n nclzire. Climatizarea este utilizat pentruevaluarea sarcinilor interne, care sunt datorate, n

principal, iluminatului n perioadele de var.Aceasta implic o reducere important a tuturor

nevoilor energetice (cu excepia celor n nclzire)cnd lumina natural este valorizat chiar cu ajutorulunui dispozitiv de control de lumin.

Utilizarea luminii naturale este importantpentru orientarea birourilor n cldirea de referin,cum este artat n Fgura 10. Punerea n funciune ailuminatului electric n tot timpul anului, care estecomplementar luminii naturale, variaz n funcie de


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orientarea birourilor i de anotimpuri. n Trappes in alte locuri, orientarea spre sud este mai interesantn valorizarea luminii naturale.

5. Concluzii

Acest articol ilustreaz importana lurii nconsideraie a interaciunii dintre iluminat i sistemulHVAC. Aceast noiune este util pentru a nelege i

prevede nevoile energetice ale cldirilor de birouri.Noua reglementare termic francez [21] face caacest subiect s fie mai sensibil. La ora actual,scopul este de a ameliora performanele termiceale noilor cldiri de birouri cu 25%. Ideea globaldespre proiectarea arhitectural i tehnologiceste important n ameliorarea managementuluide economie a cererilor de energie. De exemplu,

alegerea unor dispozitive scumpe de control de

lumin trebuie s fie justificat printr-o reducereimportant a consumului de energie, nu numai niluminat, ci i n consumul global care include inclzirea i climatizarea.

Urmtoarea etap a acestui studiu va figeneralizarea formulelor de energie pentru altecldiri n concordan cu proprietile arhitecturalei activitile desfurate la interior. Aceasta va fifcut mai uor cu ajutorul noului program de calculLIGHT care permite includerea luminii naturale icelei electrice n bilanul energetic termic cu ajutorulmodulului CA-SIS i al altor module termice. Altemodificri trebuie s in cont de creterea ncrederiin aceste module i programme, n particular pentruun control mai bun al confortului vizual (controlulorbirii, bilanul de luminane) care trebuie s fiemereu asociat n calculele de economie de energie.

Traducerea autorului


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CERCETRI PRIVIND INFLUENA LUMINII MONOCROMATICE DETIP LED ASUPRA PERFORMANELOR PRODUCTIVE, CALITII

CARCASELOR I A STRII DE SNTATE A PUILOR BROILER

GheorgheCMPEANU *, MariaCOSTEI *, IonVIAN *, StelianMATEI **NicoletaCIOCRLIE *, AlinaORAN *, EmanuelaPETRE *

*Universitatea de tiine Agronomice i Medicin Veterinar Bucureti**Universitatea din Stellenbosch, Cape Town

Iluminatul electric este important n managementul modern al creterii puilor. Studii recente aratc sisteme de iluminat cu lumin monocromatic afecteaz creterea puilor broiler. 480 pui broilermasculi (Cobb 500) au fost amplasai n patru compartimente experimentale separate. Hrana i apaau fost administrate ad-libitum. Iluminatul a fost programat pentru 23 ore de lumin i o or de

ntuneric pe ntreaga perioad a experimentului. Tratamentele luminoase au fost: lumin alb normal- martor; lumin albastr (472 nm), lumin verde cyan (505 nm), lumin verde nchis (526 nm).Pe durata experimentului au fost nregistrate: greutatea corporal, sporul n greutate zilnic mediu,consumul de hran i eficacitatea hranei. La sacrificarea puilor au fost prelvate eantioane de carne,

snge i ochi. Sporurile n greutate i eficacitatea hranei au fost semnificativ mai mari n grupurilesupuse luminii verde. Profilele proteic i metabolic nu au fost afectate de lumina monocromatic.Rezultatele experimentale sugereaz c lumina verde cyan i lumina verde nchis stimuleaz cretereapuilor broiler.

1. Introducere

Lumina este unul dintre cei mai importani factoride microclimat ntlnii n adposturile destinatecreterii psrilor, deoarece influeneaz n maremsur att performanele productive ct i celede reproducie ale psrilor. Din acest motivadposturile n care sunt ntreinute psrile trebuies realizeze condiii adecvate, care s corespundcerinelor fiziologice ale organismului.

n adposturile moderne, iluminatul electriceste singura surs de lumin asigurat psrilor.

Rolul luminii n creterea psrilor este binecunoscut, aceasta influennd prin intensitate, durat(fotoperiodism) i program de aplicare (Andrews iZimmerman 1990).

Ochiul psrilor, similar cu cel al omului, estecapabil s disting lumina n spectrul 380 760nm. Vederea cromatic este prezent i la psriledomestice, dar experienele privind percepia luminii

monocromatice arat c psrile nu pot recepiona

radiaiile cu lungime de und mic (indigo i violet),din cauza absorbiei acestor radiaii cu slab puterede penetrare de ctre picturile uleioase din retin.

n tehnologia de cretere industrial a psrilor,pentru realizarea iluminatului electric s-au utilizatdiferite surse cum ar fi: lmpi cu incandescen,lmpi fluorescente. Aceste surse de luminelectric s-au dovedit a fi neeconomice, din acestmotiv o nou i eficient lumin monocromaticde tip LED a fost introdus n industria creterii

psrilor pentru maximizarea performanelor. Noile

tehnologii de iluminat ofer avantaje cresctorilorde psri, n sensul economisirii energiei consumatei a mbuntirii performanelor (Vandenberg iWidowski, 2000).

Ca urmare a faptului c la iluminatul artificial aladposturilor destinate creterii psrilor se folosescnc surse de lumin tradiionale i, deoareceopiniile cercettorilor care au studiat efectul luminii


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monocromatice de tip LED asupra psrilor suntdiferite, obiectivul acestei lucrri a fost acela de astabili influena iluminrii cu LEDuri cu diferitelungimi de und asupra performanelor de cretere,a strii de sntate i a eficienei economice ncreterea puilor.

LED-urile utilizate n experiment au fost realizaten laboratorul de cercetare al Facultii de InginerieElectric din Stellenbosch de ctre cercettorulProf. Stelian Matei. Acestea au avut diferite lungimide und, respectiv: albastru 472 nm, verde cyan 505nm, verde nchis 526 nm.

Tabelul 1Schema experimentalLoturi Tratament Obiective urmrite n experiment

Martor Lumin albParametrii productivi urmrii Evoluia greutii corporale pe faze de cretere (g) Sporul mediu zilnic pe perioade de vrst Consumul specific (Kg n.c./Kg spor)

Experimental 1 Lumin monocromaticalbastr

Indicele de pstrare al efectivului (%)

Experimental 2 Lumin monocromaticverde cyan

Compoziia chimic brut a carcaselor

Experimental 3 Lumin monocromatic

verde nchis

Ultrastructura fibrelor musculare

Modificri ale structurii retinei puilor din experiment Modificri hematologice ale puilor din experiment Urmrirea comportamentului psrilor pe perioada

experimental Eficiena economic (%)

2. Materialul biologic i metoda de lucru

n cadrul experienelor efectuate pe puii broiler s-a

utilizat ca material biologic hibridul comercial Cobb500. Studiile s-au desfurat n patru compartimenteexperimentale distincte, pe un numr de 480 pui,care au fost mprii n mod uniform cte 120 pui/lot (6 repetiii). Creterea s-a fcut pe o perioad de42 zile, n cuti metabolice, n regim de neutralitatetermic (28 C n prima sptmn i 24 C nurmtoarele sptmni). Schema experimental este

prezentat n Tabelul 1.Fiecare compartiment experimental a avut

contor de nregistrare a consumului electric propriu.

nregistrarea consumului electric a fost fcut zilnici sptmnal. Durata iluminrii a fost de 23 h/zi latoate loturile, dar a diferit ntre loturi prin culoarealuminii din compartimentul experimental.

Reetele de nutre combinat au fost formulatepe perioade de cretere, n prima perioad reeta aasigurat 3078 Kcal/Kg EM, 23,03%PB, i 1,40%lizin; n perioada de cretere i ngrare reeta a

avut un coninut de 3168 Kcal/Kg EM, 22,00%PB i1,30% lizin; iar n perioada de finisare 3226 Kcal/Kg EM, 19,15% PB i 1,14%. Hrana i apa au fost

administrate ad libitum.Pentru stabilirea performanelor de cretereale puilor din loturile experimentale s-au efectuatcntriri de control; pe baza greutilor corporalerealizate s-au calculat sporurile n greutate. Deasemenea, pentru aprecierea modului n care a fostvalorificat hrana, au fost nregistrate cantitilezilnice de furaje ingerate (pe loturi, variantei repetiii), pe baza crora au fost calculateconsumurile totale i cele specifice de nutreuricombinate/kg spor.

Aprecierea calitii carcaselor s-a realizat princntrirea acestora i a poriunilor lor anatomice,iar pe baza greutii absolute s-au obinut datede randament i proporii ale diferitelor poriunirezultate prin tranare, prin raportare la greutateavie i la greutatea carcasei dup eviscerare. Deasemenea, pentru estimarea dezvoltrii organelor iglandelor s-au fcut msurri ale greutii acestora.


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Probele de carne au fost supuse unor analizede compoziie chimic brut, coninut n colesteroli de ultrastructur a fibrei musculare. n vedereastabilirii structurii retinei, globul ocular al psrilora fost examinat histopatologic la vrsta de 28 i 42de zile.

La sfritul experimentului, puilor sacrificai

li s-a analizat i coninutul osului tibia n cenubrut, calciu i fosfor. Pentru determinarea calciuluis-a folosit metoda volumetric, iar fosforul a fostevideniat prin metoda colorimetric.

Prin analiza probelor de snge recoltate la 28i 42 zile s-au stabilit valorile hematologice ale

psrilor i profilul metabolic al acestora.Rezultatele obinute au fost prelucrate statistic

folosind programul Microcal Origin calculndu-sesemnificaia diferenelor ntre loturile experimentalecu ajutorul testului Student T, pe baza lor formulnd

o serie de concluzii i recomandri.

3. Rezultate i discuii

3.1 Evoluia greutaii corporale pe perioadaexperimental

Tabelul 2 prezint dinamica greutii corporale apuilor pe perioade experimentale.

Se constat c la vrsta de 21 zile greutatea mediecorporala a broilerilor nregistreaz valori cuprinse

ntre 794,01g la lotul Martor i 837,37 la lotul L3(lumin verde nchis), diferene semnificative pentru

probabilitatea dep


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3.3 Evoluia consumului specific pentru a obine1 kg spor n greutate

n ceea ce privete consumul de nutre combinatntre 0-21 zile, se constat c acesta a avut valoricuprinse ntre 38,18 g/zi la lotul L3 (lumin verde)comparativ cu 36,11 g/zi lotul Martor (lumin alb).n acelai timp, puii din lotul L2 (lumin verde cyan)

au nregistrat sporuri de 37 g/zi, iar cei din lotul L1(lumin albastr) numai 36,68 g/zi. ntre 21 i 35zile, valorile sporului obinut se nscriu ntre 71,69g/zi la lotul L2 (lumin verde cyan), fa de 66,08g/zi la lotul L1 cu lumin albastr.

n perioada de finisare (35-42 zile) se remarc ombuntire a consumului specific la toate loturileexperimentale: 2,600 kg/kg spor la lotul L2; 2,606kg/kg spor la lotul L3; 2,730 kg/kg spor la lotul L1;fa de 2,613 kg/kg spor lotul Martor .ecedent de

puii lotului L2 (lumin verde cyan) 1,879 kg/kg

3.4 Evaluarea caracteristicilor calitative i aprofilului metabolic i hematologic al puilorexpui la aciunea luminii monocromatice

Experimentul care st la baza prezentuluiraport urmrete efectul luminii monocromatice(albastr, verde deschis i verde nchis) asupra

performanelor de cretere a puilor broiler i asupra

caracteristicilor trofico-biologice ale crnii psrilorcrescute n aceste condiii. n urma sacrificrilor,

puii din loturile experimentale au fost supui uneiserii de msurri privind dezvoltarea carcaselor i atractusului digestiv.

Greutatea la sacrificare i greutatea net acarcaselor este prezentat n Figura 3.4.1.

Figura 3.4.1 Prezentarea greutii la sacrificare i a greutiinete la puii broiler crescui n loturi cu lumin monocromatic

diferit

De asemenea, n urma sacrificrilor a fostanalizat i greutatea organelor puilor pe loturiexperimentale. n Tabelul 3 este redat comparareaacestor valori i procentul din greutatea net.

Pui broiler din lotulmartor (M)

Pui broiler din lotul(L

1)


2)


3)

Greutatea inimii, g 8,5600,792 9,1380,428 8,0020,749 8,5600,600

% din Greutatea net 0,4050,034 0,4480,013 0,3810,035 0,4010,023Greutatea ficatului, g 42,1103,777 39,1631,183 42,1975,155 40,7801,194

% din Greutatea net 1,9880,154 1,9230,029 2,0130,280 1,9110,055

Greutatea pulmonului, g 8,9831,115 8,9920,333 13,5321,310 9,5780,516

% din Greutatea net 0,4230,044 0,4410,025 0,6450,046 0,4480,021

Din analiza rezultatelor obinute se constat cnu s-au nregistrat diferene semnificative din punctde vedere al greutii inimii i ficatului, n cazul

pulmonului ns, rezult diferene semnificativeale greutii acestui organ att ntre lotul Martor(valoarea minim) i lotul cu lumin verde cyan L2(valoarea maxim obinut), respectiv 4,549 g, cti ntre lotul cu lumin albastr L1 i cele cu luminverde L2 i L3 (verde cyan i verde nchis): 4,54 gi respectiv 0,586 g.

Aprecierea comparativ a compoziiei chimicea carcaselor puilor din loturile experimentale

Compoziia chimic brut a carcaselor analizatcu scopul depistrii potenialelor diferene alecalitii nutritive a crnii obinute de la puii din cele4 loturi experimentale (sacrificai la 28 de zile i la42 de zile) evideniaz performane superioare la

puii crescui n loturile cu lumin verde, n specialverde cyan. Figura 3.4.2 prezint proteina brut dincarcasele puilor, iar Figura 3.4.3 - grsimea brut,ambele raportate la substana uscat.

Tabelul 3Compararea greutii organelor la puii broiler crescui cu lumin monocromatic diferit


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Figura 3.4.4 Profilul proteic la puii de 42 de zile din loturile experimentale expuse la aciunea luminiimonocromatice

Figura 3.4.2 Protein brut (% SU) determinat din carcasele puilor broiler sacrificai la 28 i 42 de zile i crescui n patru loturiexperimentale cu lumin monocromatic diferit

Figura 3.4.3Grsime brut (% SU) determinat din carcasele puilor broiler sacrificai la 28 i 42 de zile i crescui n patru loturiexperimentale cu lumin monocromatic diferit

Figura 3.4.5 Profilul energetic (colesterol total i trigliceride) la puii de 42 de zile din loturile experimentale cu luminmonocromatic


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Din rezultatele determinrilor se constat ccele mai mari valori la coninutul n protein brutau fost obinute la lotul cu lumin albastr, iar ceamai mic valoare a grsimii brute a fost prezent ncarcasele puilor din lotul cu lumin verde nchis.

Analiza profilului metabolic al puilor din

loturile experimentale expui la aciunea luminiimonocromaticePentru puii de carne din loturile experimentale,

s-a aplicat profilul metabolic la vrsta de 4 i 6sptmni, respectiv la 28 i la 42 de zile (Figurile3.4.4 i 3.4.5)

Comparnd valorile determinate pentru fiecareparametru luat n calcul la stabilirea profiluluiproteic i energetic se observ c puii analizain acest experiment nu sugereaz existena unor

probleme metabolice.

Examenul histopatologic al probelor prelevatede la puii broiler din loturile experimentale culumin monocromatic

Examenele histopatologice ale probelor deanalizat s-au efectuat pe patru pui n vrst de 28 dezile i pe 16 pui de 42 de zile din cele patru loturiexperimentale.

S-au prelevat fragmente de muchi scheletic dinzona pectoral i femural i glob ocular (retin),fixarea s-a fcut n formol Baker, incluzia la parafin,secionarea la 5 m, iar colorarea seciunilor prinmetoda tricromic Masson (HEA).

Examenul histopatologic efectuat la puii de28 de zile i la cei de 42 de zile a evideniat slabemodificri distrofice n probele din musculatur idiscrete leziuni la nivelul retinei, n special la puiidin loturile cu lumin albastr i verde nchis. Puiidin loturile cu lumin verde cyan i cu lumin albau prezentat rezultate corespunztoare.

4. Concluzii

Din analiza datelor prezentate se desprindurmtoarele concluzii generale:1. Privitor la influena luminii monocromatice de tipLED asupra performanelor de cretere ale puilor

broiler se constat c:1.1 Spectrul luminii monocromaticeinflueneaz rata de cretere a puilor broiler

astfel nct puii din loturile L2 (luminverde cyan) i L3 (lumin verde nchis) aurealizat rata de cretere i sporul n greutatesemnificativ mai mari dect cei crescui sublumin albastr sau alb.1.2 n ceea ce privete eficiena utilizriihranei se remarc aceleai loturi care au

beneficiat de lumin verde, respectiv L2i L3, care au realizat un consum de nutrecombinat cu 5,46% i cu 1,14% mai micdect puii lotului Martor (lumin alb).

2. Privitor la influena luminii monocromatice de tipLED asupra calitaii carcaselor i a strii de snatatea puilor broiler se constat c:

2.1. Greutatea la sacrificare a puilor, greutateasemicarcaselor i cea a organelor interne aufost influenate semnificativ la loturile culumin verde (verde cyan i verde nchis) cu

5,2 i 6,2% mai mari dect la lotul Martor.2.2. Profilul metabolic nu a fost influenati se ncadreaz n valorile de referincorespunztoare speciei i categoriei pentrutoate loturile experimentale.2.3. Starea de sntate a puilor nu a fostafectat, la examenul histopatologic s-auevideniat slabe modificri distrofice n

probele din musculatur i discrete leziuni lanivelul retinei, n special la puii din loturilecu lumin albastr i verde nchis. Puii dinloturile cu lumin verde cyan i cu luminalb au prezentat rezultate corespunztoaren urma examenului histopatologic.

Bibliografie

1. Vandenberg, C., Widowski, T., 2000, Investigating theeffects of alternative light sources on behaviour, welfareand performance of poultry.Animal and Poultry Science(Guelph 1998-2000)2. Rozenboim, I., Zilberman, E., Gvaryahu, G., 1998,

New monochromatic light source for Laying hens,Poultry

Science773. Andrews, D.K. and N.G. Zimmerman, 1990, Acomparison of energy efficient house lighting source and

photoperiods,Poultry Science694. Woodward, A.E., J.A. Moore and W.O. Wilson, 1969,Effect of wavelenght of light on growth and reproductionin Japanese quail,Poultry Science48


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Gheorghe CMPEANUProfesor universitar, doctor n chimieef al Catedrei de Chimie, Facultateade Biotehnologiie-mail: [email protected]

Maria Virginia COSTEILector dr.

Alina Ruxandra Eugenia ORTANAsistent drd.e-mail: [email protected]

Emanuela Irina PETREAsistent drd.e-mail: [email protected]

Universitatea de tiine Agronomice i MedicinVeterinar BucuretiFacultatea de BiotehnologiiBd. Mrti Nr. 59, 71331 Bucureti, RomniaTel.: +40.21.2242576Fax: +40.21.2241825

Lucrare prezentat la A 2-a Conferina InternaionalILUMINAT 2003, 8-9 Mai, Cluj-Napoca, Romnia

RESEARCHES CONCERNING THE INFLUENCE OF MONOCHROMATICLED-TYPE LIGHT ON THE PRODUCTIVITY PERFORMANCES, QUALITYOF THE CARCASSES, HEALTH AND METHABOLIC PROFILE OF THE

BROILER CHICKENS

Electric illumination is crucial in modern broiler management. The latest studies show that a new andhighly efficient monochromatic light system affects the growth of broiler chicks. Four hundred andeighty male broiler chicks (Cobb 500) were raised in cages in four experimental rooms separately. Feedand water were provided for an ad-libitum consumption. The light was scheduled for 23h of light and1h of dark during the entire experimental period. Light treatments were: control-normal white; blue(472 nm), cyan green (505 nm ), dark green (526 nm). During the experimental period were recorded:body weight, the average daily gain, feed consumption and feed efficiency. At the slaughtering meat

samples, blood samples, eye samples were taken. The weight gain were significantly higher in thegroup reared under green light, and the feed efficiency were enhancement in the same groups. Theproteic and metabolic profile were not affected, by the monochromatic light. The experimental resultssuggest that the cyan green light and the dark green light stimulate the growth of the broilers.

Light is one of the most important microclimate

factors found in places for growing birds, as it is

greatly influencing both bird development and

reproduction. Therefore, these places where

birds are kept and grown must have adequate

conditions, correlated to the physiological needs

of the organisms. In modern systems, electric light

is the only source of light available for birds. The

growth of broiler chicken - largely used in bird meat

production industries - is significantly influenced by

the type of light. Industrial bird growth technology

is using different light sources such as: incandescent

or fluorescent lights.These electric light sources were

found to be uneconomical, therefore a new, efficient

monocromatic light source of the type LED has

been introduced in poultry farms. The technology

used to produce LEDs involves growing crystalline

structures of semiconductor material layer after

layer (layer on top of layer), making possible to

use semiconductor materials that could not be used


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before, and also insures the production of structures

of high precision and purity. Recent technologies

made possible the production of LEDs with a

combination of colours. Because classical artificial

lighting systems in chicken farms are still used and

because scientists express different opinions on the

effects of LED monocromatic light (with variouswavelengths) in birds, we found the study of the

influence of LEDs on chicken growth parameters,

health and economic efficiency interesting to explore

in the present project. The LEDs used in the present

work have been produced by Prof. Stelian Matei at

the research laboratory of the Faculty of Electrical

Engineering in Stellenbosch. These had various

wavelengths: blue (480 nm), cyan green (535 nm),

dark green (560 nm).

Materials and methods. The experiments used thehybrid COBB 500 chicken, available commercially.

These hybrids have fast growth, feed efficiency, high

slaughtering yield and good livability. Four hundred

and eighty broilers (male) COBB 500 were used in

four different rooms during experiments (Table 1).

The birds were raised in cages, in uniform growth

conditions, at thermic neutrality (28 C in the first

week and 24 C all others). Electrical consumptionwas measured separately in each experimental

room weekly. A 23 h light - 1 h dark was used in all

rooms, but light colour varied

lighting engineering 13 vol6 2004

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