Remodeling and adaptation of "Plaza de America" Expo' 92 Pavilion to Faculty of Engineering

SEMINARIO DE ARQUITECTURA Y MEDIO AMBIENTE Jaime López de Asiain y Martín José María Cabeza Lainez Víctor Moreno Jiménez Escuela Técnica Superior de Arquitectura Av. Reina Mercedes 2,41002 Seville Ph 5 4556555 FAX 5 4556534 O/FOREWORD Towards aposttragic society The famous interior designer Comelius Gurlitt opens his chapter on Windows of 1888 with a few cursory remarks on their most recent de velopments ,namely, the gradual increase in the size of the openings themselves as well as that of the individual panes of glass: "The last words of Johann Wolgang Goethe before he died, "More light", have penetrated our dwellings". he argued; and soon after, this statement soared upon the latter developments of Modem Twentieth Century Architecture. Nowadays we are well aware of the fact that the excess in glazed surfaces does not provide thermal or daylighting advantages but it does prejudice the performance of the buildings through exponential increases in the conditioning loads (thermal, luminous and acoustic). These mechanical constraints demand uniformity to work adequately and thus we arrive at the result of total homogeneity in the architectural spaces. At the same time, low-cost conditioning Systems were produced (especially in the item of artificial lighting), and so the gothic-romantic obscurity is put on the spotlight whilst the environment is neglected and paradoxically the dependence on this same environment is almost total. As architect Luis Barragán pointed out, the majority of human activities were developed under excessive illumination. In the summit of this process the playwright and philosopher Jean Paul Sartre in one of his most important dramas "Huís Clos” depicts "Hell" as a windowless artificial place where electric lighting has no possible regulation ñor variation. In the beginning it was darkness in the chambers of mankind, but mankind made a new light and feeling equal to the Gods mankind thought that it would last forever! Today we feel astounded to see how much futility was dropped on these artificial Systems weak against time winds and subsidiary of waning energies. Perchance there is no sadder tragedy than the one of those "glassboxes" drifting with exhilerated air conditioning Systems and forsaken in places near the Equator or the Poles, as the remaining satellites of an extinct planet. The same happens in Chandigarh, the town of automobiles where very few can afford even a bike. Master Tanizaki in his famous book In Praise of Shadows reminds us of how "...our own imagination moves within a lacquer-black obscurity, whilst the people ffom the West confer a crystal transparency even to their ghosts..." "...we admire this faint glow, made of extemal light andmisleading appearance, caught in the surface of duskcoloured walls scarcely preserving the remains of life. For us this brightness upon a wall, those shades, are worth a whole array of decoration and we are ne ver tired of this visión..." What do we propose? That the process of illumination and in a sense the whole environmental question have no meaning by themselves unless they interact with architectural surfaces; modulating, rebounding and regaining the "proximity" that Martin Heidegger thought it was missing. The same architectural foim determines the measure of environmental exchanges. 549 We have continued on the research line abandoned by H. H. Higbie -who was perhaps unaware of the potential of his method- to define a "new method of configuration factors" (R) which is based on Helmholtz 's reciprocity aw and Lamben s corollary (1). It is however emotive to see by reading Higbie s original papers how cióse he was to finding a solution and yet so far away from architectural aims. Henceforth we will understand architecture as a System of filters (acoustic analogy) which preserving the harmomc vectors of an environment, neutralize the discordant elements until they come to reinforce the original harmony. What is then the role of the aforementioned Systems of filters? The role is to generate transformations that relate outside environmental fields with the mtemal field (or human scale). While the outside field is consfdered of an infinite vanation the rntemal field is relatively constan! as only the range of human comfort ,smkmble the ñinction that regulates the transfer from one to the other is given by architecture itself. m l PPn=‘Ple oftdMtity lies in the f-.ct that there may be sundry climate-responsive architectures as S o f v ^ t e n d ^ S t í c T t0 Van°US eXtemal C°DdÍtÍOnS’ bU‘ 1116 mternal field from 1116 comfort What do we intend with simulation, the utmost form of knowledge? We try to build a bridge between and ^lrtual ieah% We trTt0 recogmze every point of the space, to retrieve the lost "proximity" by opposmg reality to scenography, avoidmg the fashionable trend to see the environment exclusively in terms of pi ubDcciive. We intend to abolish the metaphysical link that our Western society has always set between body and soul the “ “ “ dthe e®5Ct’ * e “8“ » af d the actor, Destiny and the Man, God and the creature. If the whole operation !L ° ,h‘dd,en’ whytordow sh™ld we make somethingdivine out of this? thepuppet is not heldby threads No ? r^ d’ "í) n° metaphor, no Destiny; as the puppet does not imítate the creature, man is no longer a puppet between the hands of God, the inside does not reign over the outside, on the contrary, for the fírst time in architecture íhc outside reigns over the inside. As Joseph Rykwert could have argued, the new letter of the alphabet is Daleth: the cosmic door towards a compassionate architecture. A/ANTECEDENTS o S t ^ t l ^ h e ^ L ^ f " ' 6 “ d ^ S°lar 6Xp0SUre °fthe Plaza de A™ ™3 Pavili°" with fiie intention ot adaptmg it for the Faculty of Engineenng, we propose to improve the environmental conditions of the cited building and íts annexed laboratones of new construction through arcitectural design. A necessary consequence of this process will be a reduction in annual energy consumption (which will become ared^fiot0T calculat'ons’ar®dac“°“ fro™3 “ i*1'011 Agonesper hour to 1.6million) to which we must add ^provedworldngc?ndfiimIs.SC^e^U 6 ’ “ WÍ“ benefit USerS' C°mfort wíth the clear advantage in On the other hand, these types of architectural modifications will provide Solutions from a building point of view to pressing environmental problems. Consequently, via this operation, rather than infioducing complications to the project we are guaranteeing its futura valué for generations to come. 6 fo 1 lowing piagraphs ob3ectives’ we have elaborated a senes of strategies which are outlined in the 550 B/BUILDING SYSTEMS 1. NATURAL ILLUMINATION AS A PASSIVE COOLING SOURCE The dominant concern in the climate where the Plaza of America is situated is excessive heat in conventional buildings (2). Outside temperaturas in excess of 40° C have been recorded between May and September. Nevertheless, in the months between November and February, although statistically it is rarely below 0o C, it is necessary to provide some form of heating to maintain ideal comfort conditions. Experiments completed by SAB (3) demónstrate that it is possible to obtain most of this heating by completely natural means, i.e. passive systems. The initial concern we find is that although theoretically it is possible to limit solar gains through insulated walls and roofs, in practice this rarely occurs as a certain level of illumination is necessary in order to inhabit the space. Assuming then that the heat generating by occupants and machines is low, our main objective will be to provide adequate task lighting with minimal solar gains. The source presenting the optimal light-heat ratio (up to 160 lm/watt) is daylighting, especially beam daylighthing. Let us consider that the most evolved mercury vapor lights, with their poor color rendenng, only achieves 80 lm/watt. Therefore, spatial illumination should be accomphshed primarily by solar illumination, resulting in considerable psychological and ecological advantages. Nonetheless this type of illumination has two drawbacks -its directionality and its high intensity. To avoid these drawbacks,itis necessary to consider systems of light diffusion These systems, although not designed to totally eliminate the disadvantages, can be utilized to our benefit (in other words, it is possible to appreciate the variety of sun positions and intensities and at the same time obtaining a balanced and regular luminous environment). The general strategy will be to create geometncal conditions in which direct and indirect lighting will complement one another. In the building under consideration, if the faqades were to be maintained without shading devices (especially on the south and west) in winter, although natural illumination would be acceptable at a meter from the wmdow, four meters from the same window the illumination would be less than 120 lux and six meters away the illumination of 60 lux, would be insufficient. Having in mind the building's large halls, the aforementioned illuminance valúes reveal that only ten percent of the considerad spaces would have some guarantee of sufficient daylighting. However, it must also be cited that all of these spaces would not be totally habitable next to the glass because of the inevitable thermal problems. In summer if solar control was not present, the illumination valúes would rise disproportionately. One meter away from the window we would find a level of 5.000 lux and six meters away 500 lux, creating overheating and glare resulting in either seasonal adjustment or supression of natural source with the necessity to use electric lighting and its subsequent problems. On other hand, in the rooms with northem onentation, the illumination would be insufficient, similar to winter conditions. u By the means of solar control in the form of fins, bnse-soleil or Ughtshelves, we would dimimsh the intensity of light right next to the window and increase daylighting, through reflection, away from the wmdow, and at the same time avoiding the problems of glare and overheating. According to our calculations, with our proposed design, 80% of the spaces would be guaranteed sufficient natural illumination with the subsequent important energy savings in cooling, heating and electric lighting. In the classrooms, daylighting varíes gradually from 1.800 to 800 lux at distances up to 20 meters, providing balanced lighting through most of the rooms, an effect unattainable with conventional fenestration, whose máximum effective light penetration is only 5 meters. The subsequent cooling load due to heat transfer ought to be as low as 10 W/m2 while electric lighting would create a load equivalent of 65 W/m2, which is to say the load reduction is 85%. The SAB has employed other Systems with success to improve daylighting, such as south oriented monitors (whose typology approximates sawtooth skylights with the difference being that they are usually incorTectly oriented to the north, (see S.G. Ramaswamy (4)). In order to utilízate them, they ought to be situated, logically on the building's roof, but if one wishes to use them to light lower levels, they have to be connected with patios, the so called Mediterranean atrium, of ampie proportions to create a fríendly, interior space. Following this idea, the central space of the existing building has bfeen converted into a library, transforming a great glazed vault that receivcs undesired solar gains from all parís of the sky dome into two south-facine conoidal monitors. At the same time the monitors are provided with large diffusing elements or baffles to regularize light distnbution without impeding its entry and the dynamic qualities produced by daylighting. Observing the graphic results of the natural illumination calculations, we can study the example of July when the new systems create lighting levels that reach the range of700 lux and therefore loads in the arca of 6 W/m2 while with the oíd vault the lighting valúes were over 20.000 lux, unacceptable levels for visual comfort besides creating a thermal load of 160 W/m2, that is to say a load increase of2.600% and a predictable raise of annuai expenses solely for this concept of 10.000 ECU. On other hand, in January, the illumination and solar gain levels derived from the oíd system are lower than those gained by the new one—1.200 lux in the existing and up to 3.000 in the proposedfor sunny davs 165% of January days). It is also necessary to note that the aesthetics and perception of the spaces has been improved with the introduction of new illumination rythms, pattems that have been elaborated in architecture in the same way that music is composed with a phrase or scale, controlling the tone and duration of sensations and producing for the outside world cadenees, eyeles and seasons in etemal succesion. The same concept is folio wed for the retrofitting of parabolic vaults of the side patios, with the difference being that the previously noted geometric conditions give rise to parabolic conoids, also aesthetically suggestive and of great structural resistence. The complement of natural illumination with artificial for special situations or for nightime use is extremely important. In the first place, this source of illumination is as similar as possible to natural through adequately placed and distributed luminaires of good color rendering (more than 5.000K). In the second place, systems of light regulation, such as dimmers and luxmeters, will be used according to the availability of daylighting alwaysñnding the best possible balance. ** 6’ At the same time, the integration of cooling and ventilation systems was considerad as well as sprinkler and smoke detection systems. Remember that the analysis of natural illumination has been studied in all cases with the flux transfer method, a novel versión that ineludes both overcast and beam daylighting conditions has been developped by SAB. 552 2. PASSIVE COOLING 2A.- SOLAR PROTECTION Once the problem of natural illumination is addressed, as shown an essential point for optimal cooling, we can apply the strategies that lead to temperatura reduction in interior spaces and the additions of the projected building. In the first place, there is the need to protect spaces from excessive solar gains. A elassie problem arises here given that the times of máximum temperatura in Seville's climate, that is late July and early August, are not symmetrical with respect to June 21st. Therefore, fixed solar protection for the overheated period limits sun penetration in early spring when it is desirable forpassive heating. 2B- SOLAR COORDINATES We fmd on the Southern faqade that protection of 60 degrees is sufficient (after 60°, the sun rays would not enter). To the contrary, the west fa? ade is most unfavorable and even an angle of 30 degrees leaves parí of the thermal patch without cover, although within an acceptable range. With the east faqade, a nominal protection of 65 degrees is enough. Protection is not needed on the north faqade. 2C.-VENTILATION After establishing the apropriate levels of insulation, with which one can achieve important favorable changes with respect to the exterior temperatura (it is necessary to note that if the proposed design is not executed, the building will have an impoverished interior environment -as we have often noted in conventional buildings, an environment less habitable than exterior conditions) the following step would be to establish the ventilation conditions especially nightime ventilation through adequate orientation of opemngs that do not prejuice the environment. We can utilize simple Windows or elements that emphasize the so called "stack effect , a phenomenon whereby air may also be filtered of contaminants in order to retum puré air to the building. This means that the south and west faqades will have a good level of ventilation, but for this it is necessary that at least 50% of the fa? ades glazing will have to be operable in order to attain the desired effeets. In the opposed farades, to achieve cross-ventilation, at least 30% of the glazing must be operable, but for reasons of mainteñance, we will continué with 50% operable glazing. The former reference to the nightime component, result from the fact that night is really the best time to take advantage of the effect produced by ventilation. It is necessary to realize that during the day, temperaturas are too high to obtain appreciable results. In effect, during summer mghts, temperaturas are less than 25 C (the lower temperatura limit established in HVAC noims) and it is then adequate to produce "free cooling . This cooling acts in principie over the thermal masses -slabs and partitions- of the edifice, being stored, for later use to reduce the temperaturas of the following day. Having in mind the aforementioned, and the thermal mass and aperature sizes, according to formulas of Gi voni and Evans developped experimentally by SAB, we will have reductions of máximum interior daily temperaturas of 3°C to 4° C in July and August, and 2 to 3°C in June and September. That is to say, that if the máximum daily indoor temperatura is 31°C in July, with these steps we can obtain valúes less than 28 C with its consequent reduction in cooling load and subsequent energy consumption. This reduction, we can calcúlate at 20%. 553 A fürther recourse is mecfaanical ventiiation -either simple fans or using the air-conditioning in a ventilation mode. The cost of these means is irrelevant compared with the reduction in energy consumption. However, in all ways natural ventilation in this building is perfectly viable, coverine the case ofmechanical failureormalftinctioning. 6 3. PASSIVE HEATING Once the main climatic problem in Seville is analyzed, cooling, it remains to comment on heating Systems that, although of less importance, have a considerable effect on the comfort of occupants. ° Given the normal temperatures and realizing the solar gains achieved through the glazed openings sufficient energy can be obtained and stored in the thermal mass and later re-radiated to obtain thermaí comfort without energy consumption. To achieve this, it is necessary to recognize the zones of energy loss -primarily glazing- and insulate them theimally or cover them in winter nights with protection or venetian blinds. Where this is not possible, special low transmission glass should be used, like in the north farades. Finally, in the defmitive project, there are circumstances that oblige us to use conventional heating and cooling Systems, then these Systems will always complement the passive ones, never eliminating or negating their effect. However, with those strategies, we have demonstrated a saving more than 45% over current energy use. 4. ACOUST1CS Except for the spaces destined for lectures, the requeriments will be insulation against outside noises and absorption of interior noises. For the outsides, noises, the walls have standards of heat and acoustic insulation, as already commented and their mass should be sufficient, achieving a valué above 50 A decibels according to calculations and experiments. To absorb interior noises, surfaces of mineral fiber or cork are utilized. Other materials used are vermiculite orperlite. Reverberation times in classrooms are: T (250) =1.20 seg. T (500) =0.88 seg. T (1000)=0.72 seg. T (2000) =0.53 seg. T (4000) =0.51 seg. For offices, the reverberation time will be less than one second, in meeting halls less than point eight seconds and common areas up to one point three seconds. The halls with special acoustic requeriments should be studied independently, but the existing auditorium is considered adequate. 554 C/MONITORING To prove the aforementioned statements, the degree of each system's efficiency, level of energy use and possible improvements, some monitoring Systems must be implemented. Some important points of the monitoring procedure will be discussed. D/ URBAN SYSTEMS As an addition to improve garden and patio areas of the project, we introduce brief notes on vegetation ffom a climatic viewpoint. An^objective is to increase the use of vegetation in outdoor spaces and building surfaces, especially roof areas. Vegetation in underground spaces is also considered through the use of reflectors and light conductora. BIBLIOGRAPHY Some references by the authors on the same subject (1) European ConferenceLyon 94, "Indoor airquality". José María Cabeza et al. "ADesignStudyofa Passive Solar Office Incorporating Exhaust Air Windows and Lightshelves. (2) Passive Cooling of outdoor spaces. Jaime López de Asiain. José María Cabeza et al. PLEA 88. Oporto. Pergamon Press. See also The Open Spaces ofExpo'92. PLEA 91. Jaime López de Asiain. José María Cabeza et al. Seville. Kluwer Academic Publishera. Also Conference of José María Cabeza in Budapest Technical University in the Seminar on the Solar Technology. April 1991. (3) Prototype House in Andalucía. Jaime López de Asiain. José Mari a Cabeza et al. PLEA 86. Pees (Hungary). Pergamon Press. (4) Design and Construction ofConcrete Shell Roofs.S. G. Ramaswamy. Cap 10. Northlight ^ ) nánCReporto%nconSultancyforthe UmversdyofSeville/Expo Building B2000. N.ck V. Baker. Commission of the European Communities. (6) Passive and low energy Cooling of Buildings. Baruch Givoni. Van Nostrand Reinhold. New York 1994 555 Proceedings of the Thirteenth International PLEA Conference, Louvain-la-Neuve, Belgium, July 16 -17 -18,1996 Edited and published on behalf of the International PLEA Organisation by Prof. André DE HERDE Architecture et Climat Université Catholique de Louvain Belgium © D/1996/6596/1 All rights reserved - Architecture et Climat 1 Place du Levant - B. 1348 Louvain-la-Neuve - Belgium Tel +32.10.472142 Fax +32.10.474544 Email: deherde @ arch.ucl.ac.be PLEA 96 BUILDING & URBAN RENEWAL L O U V AIN -L A -N E UV E JULY 16 - 17 - 18 1996