fauusp, são paulo, brazil: an icon of brazilian modern ... · figure 5: studio 2. design...

FAUUSP, São Paulo, Brazil: an icon of Brazilian modern architecturewith lessons and questions to environmental design

FAUUSP, São Paulo, Brazil: an icon of Brazilian modern architecturewith lessons and questions to environmental design

1 1Rodrigo de Castro Dantas Cavalcante , Patrícia Mara Sanches and

1Joana Carla Soares Gonçalves

1Laboratório de Conforto Ambiental e Eficiência Energética, Departamento de Tecnologia da Arquitetura, Faculdade de Arquitetura e Urbanismo, Universidade de São Paulo, USPRua do Lago, 876, Cidade Universitária, São Paulo - SP Brasil 05508-080

[email protected], [email protected], [email protected]

1 1 1Rodrigo de Castro Dantas Cavalcante , Patrícia Mara Sanches and Joana Carla Soares Gonçalves

1Laboratório de Conforto Ambiental e Eficiência Energética, Departamento de Tecnologia da Arquitetura, Faculdade de Arquitetura e Urbanismo, Universidade de São Paulo, USPRua do Lago, 876, Cidade Universitária, São Paulo - SP Brasil 05508-080

[email protected], [email protected], [email protected]

1. INTRODUCTION

This research work was summarized to be presented at the International Conference PLEA - Passive and Low Energy Architecture, which in Geneva 2006 promoted the theme Clever design, affordable comfort: a challenge for low energy architecture and urban planning. The objective of the conference is to foster a multidisciplinary approach which integrates technical and architectural aspects, social preoccupations and economic data. The content presented here is based on one-year research project which compiled on-site measurements and interviews. In methodological terms, Fanger's thermal comfort indexes: PMV - Predicted Mean Vote, and the consequent PPD - Predicted Percentage of Dissatisfied were applied from which the results were compared against the occupants' opinions about the building's thermal performance. It is interesting to note that even in excellent environment conditions, there is still a number of people dissatisfied (fig. 1).

Figure 1: The PMV values correspond to (-3) cold, (-2) moderate cold, (-1) slightlycold, (0) comfort, (1) slightly hot, (2) moderate hot and (3) hot.

2. LOCAL ENVIRONMENTAL CONDITIONS

Following the bioclimatic zones of Givoni adapted for Brazilian cities, São Paulo has a mild climate, with average mean temperatures varying from

o o18 C to 22 C and humidity. In that context, 20% of the time out of the comfort zone is during summer, when the recommendations are related to natural ventilation (especially due to humidity), whilst to the other 10%, which are in winter; the strategy is passive solar heat.

3. ARCHITECTURE: THE ICONIC BUILDING

3.1 Architectural Concept

The FAUUSP building was designed by the architect João Vilanova Artigas and is was opened in 1969. Whilst the upper part of the building is a concrete box, the bottom part is seeing as a glass box. Regarding the internal arrangements of spaces and functions, the main entrance is a great open space that reveals the internal “square” (fig. 2).

Figure 2:internal square, with the entrance and the access on the left.

On the upper two intermediate floors are thet professors' rooms, lecture halls and the studios. According to the architect's intention, the lecture hall and studios should be perceived as “temple” for creation, so that they should have no windows and the communication with the outdoors is only made through the domes of the coffered roof.

Figure 3: Section from the south west to the north east orientations.

3.2 Environmental Strategies

The longer façades of the building have south-west and north-east orientations, therefore, a significantly area of the studios (fig. 4) are exposed to solar radiation during summer afternoons whilst the lecture halls get direct sun during mornings in summer, impinging on windowless and not insulated concrete walls in both cases and on the highly translucent roof.

Figure 4: Upper floor.

The central open space, among other design attributes, is justified as means of incrementing the overall stack effect in the building. However, previous studies (RUSSO, 2004) has proved that, despite the height difference between the ground floor and the top, the contribution of this atrium is not relevant unless there is external wind flow. With special reference to the choice of materials, the concrete walls lack of insulation and incur in problems related to undesirable heat losses in winter and also negative impact of radiant temperatures in summer (added to the radiant temperatures of the roof).

1. INTRODUCTION

This research work was summarized to be presented at the International Conference PLEA - Passive and Low Energy Architecture, which in Geneva 2006 promoted the theme Clever design, affordable comfort: a challenge for low energy architecture and urban planning. The objective of the conference is to foster a multidisciplinary approach which integrates technical and architectural aspects, social preoccupations and economic data. The content presented here is based on one-year research project which compiled on-site measurements and interviews. In methodological terms, Fanger's thermal comfort indexes: PMV - Predicted Mean Vote, and the consequent PPD - Predicted Percentage of Dissatisfied were applied from which the results were compared against the occupants' opinions about the building's thermal performance. It is interesting to note that even in excellent environment conditions, there is still a number of people dissatisfied (fig. 1).

Figure 1: The PMV values correspond to (-3) cold, (-2) moderate cold, (-1) cold, (0) comfort, (1) hot, (2) moderate hot and (3) hot.

2. LOCAL ENVIRONMENTAL CONDITIONS

Following the bioclimatic zones of Givoni adapted for Brazilian cities, São Paulo has a mild climate, with average mean temperatures varying from 18 C to 22 C and humidity. In that context, 20% of the time out of the comfort zone is during summer, when the recommendations are related to natural ventilation (especially due to humidity), whilst to the other 10%, which are in winter; the strategy is passive solar heat.

3. ARCHITECTURE: THE ICONIC BUILDING

3.1 Architectural Concept

The FAUUSP building was designed by the architect João Vilanova Artigas and is was opened in 1969. Whilst the upper part of the building is a concrete box, the bottom part is seeing as a glass box. Regarding the internal arrangements of spaces and functions, the main entrance is a great open space that reveals the internal “square” (fig. 2).

Figure 2:internal square, with the entrance and the access on the left.

On the upper two intermediate floors are thet professors' rooms, lecture halls and the studios. According to the architect's intention, the lecture hall and studios should be perceived as “temple” for creation, so that they should have no windows and the communication with the outdoors is only made through the domes of the coffered roof.

Figure 3: Section from the south west to the north east orientations.

: Upper floor.

slightly slightly

3.2 Environmental Strategies

The longer façades of the building have south-west and north-east orientations, therefore, a significantly area of the studios (fig. 4) are exposed to solar radiation during summer afternoons whilst the lecture halls get direct sun during mornings in summer, impinging on windowless and not insulated concrete walls in both cases and on the highly translucent roof.

Figure 4

The central open space, among other design attributes, is justified as means of incrementing the overall stack effect in the building. However, previous studies (RUSSO, 2004) has proved that, despite the height difference between the ground floor and the top, the contribution of this atrium is not relevant unless there is external wind flow. With special reference to the choice of materials, the concrete walls lack of insulation and incur in problems related to undesirable heat losses in winter and also negative impact of radiant temperatures in summer (added to the radiant temperatures of the roof).

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lecture halllecture hall

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4. ENVIRONMENTAL ASSESSMENT

Two spaces were selected for this environmental assessment: a studio and the lecture hall at the middle of the row of rooms. The choice was based on the spaces' particular design and environmental characteristics, solar exposure and occupation patterns.

Figure 5: Studio 2. Design characteristics: level 8.5m, 32m long by 17m wide and 5,5m high, with 72 domes (original domes).

Figure 6: Lecture Hall. Design characteristics: level 9.5m, 17m long by 11m wide and 3,65m high, with 24 domes.

4.1 General methodology

· On-site measurements of climatic variables in hot and cold days.· Application of questioners to obtain occupants' opinions on the thermal comfort, simultaneously to the measurements.· Calculation of PMV (predicted mean vote), according to Fanger's methodology, for hot and cold days using the results from the measurements.· Comparative analyses between the results obtained from the PMV index considering the measurements and the questioners.

4.2 Measurements

The measurements were taken in two periods of the year: from the 30th March to the 1st of April, which was still within the hot season in São Paulo and from the 22nd to the 24th of June, which is within the cold season. The climatic variables measured were air and globe temperatures, humidity and air velocity, between 8.00 am to 5.00 pm, in both spaces. All measurements were taken at 1.1m high (according to ISO 7726/98).

Figure 7: Data Loggers Onset HOBO H8 Logger; tripod with hobo and globe to measure air temperatures and humidity and globe temperatures; H&K Thermal Comfort Data Logger with tripod to measure air velocity.

4.3 Questioners

The questioners were applied during measurements. The occupants were asked three questions. The first one concerns thermal sensations, from which the PMV and the PPD results were considered through comparison between Fanger's model and measurement results. The second one is related to the occupants' expectations. They are asked whether they would like to feel warmer or colder, following the 7 points of the PMV scale. If combined with the first question, the answers from these two questions can show a different value of PPD, since some degree of comfort subjectiveness is included. This would be the case if somebody answers “slightly hot” in the first question and “no change” in the second one. Finally, the third question is about the degree of occupants' tolerance to the thermal conditions, in order to classify the importance comfort (or discomfort) to the occupants' acceptability of the space and, ultimately, their will to stay on.

Figure 8: Measurements during the hot days at the three points

5. LESSONS AND QUESTIONS FROM THE ENVIRONMENTAL STUDIES

5.1 Thermal Data Analysis

Hot days: comparing the results from the two spaces, the measurements during the hot week showed a temperature variation of 5oC, whilst the relative humidity varied from 78,1% to 48,8 % (fig. 8).

Regarding such results, it is important to underline that during the summer measurements the sky was partially clouded, which is a typical condition in São Paulo, but at the same time does not show the extreme summer conditions which the building is subjected to in clear-sky days, when the transmittance of solar radiation is substantially higher, specially in the studios, as opposed to the lecture halls where the domes were painted outside and inside.

4. ENVIRONMENTAL ASSESSMENT

Two spaces were selected for this environmental assessment: a studio and the lecture hall at the middle of the row of rooms. The choice was based on the spaces' particular design and environmental characteristics, solar exposure and occupation patterns.

Figure 5: Studio 2. Design characteristics: level 8.5m, 32m long by 17m wide and 5,5m high, with 72 domes (original domes).

Figure 6: Lecture Hall. Design characteristics: level 9.5m, 17m long by 11m wide and 3,65m high, with 24 domes.

4.1 General methodology

· On-site measurements of climatic variables in hot and cold days.· Application of questioners to obtain occupants' opinions on the thermal comfort, simultaneously to the measurements.· Calculation of PMV (predicted mean vote), according to Fanger's methodology, for hot and cold days using the results from the measurements.· Comparative analyses between the results obtained from the PMV index considering the measurements and the questioners.

4.2 Measurements

The measurements were taken in two periods of the year: from the 30th March to the 1st of April, which was still within the hot season in São Paulo and from the 22nd to the 24th of June, which is within the cold season. The climatic variables measured were air and globe temperatures, humidity and air velocity, between 8.00 am to 5.00 pm, in both spaces. All measurements were taken at 1.1m high (according to ISO 7726/98).

Figure 7: Data Loggers Onset HOBO H8 Logger; tripod with hobo and globe to measure air temperatures and humidity and globe temperatures; H&K Thermal Comfort Data Logger with tripod to measure air velocity.

4.3 Questioners

The questioners were applied during measurements. The occupants were asked three questions. The first one concerns thermal sensations, from which the PMV and the PPD results were considered through comparison between Fanger's model and measurement results. The second one is related to the occupants' expectations. They are asked whether they would like to feel warmer or colder, following the 7 points of the PMV scale. If combined with the first question, the answers from these two questions can show a different value of PPD, since some degree of comfort subjectiveness is included. This would be the case if somebody answers “slightly hot” in the first question and “no change” in the second one. Finally, the third question is about the degree of occupants' tolerance to the thermal conditions, in order to classify the importance comfort (or discomfort) to the occupants' acceptability of the space and, ultimately, their will to stay on.

5. LESSONS AND QUESTIONS FROM THE ENVIRONMENTAL STUDIES

5.1 Thermal Data Analysis

Hot days: comparing the results from the two spaces, the measurements during the hot week showed a temperature variation of 5oC, whilst the relative humidity varied from 78,1% to 48,8 % (fig. 8).


Regarding such results, it is important to underline that during the summer measurements the sky was partially clouded, which is a typical condition in São Paulo, but at the same time does not show the extreme summer conditions which the building is subjected to in clear-sky days, when the transmittance of solar radiation is substantially higher, specially in the studios, as opposed to the lecture halls where the domes were painted outside and inside.

Relative Humidity and Air Temperatures - Hot Days

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Cold days: During this time, the measurements showed small temperature variations throughout the period (fig. 9). As in the hot days, the difference between air temperature and globe temperature were irrelevant, which was expected due to the reduction of solar radiation in this time of the year.


I5.2 Comparative Analysis

The comparative analyses between the results of Fanger's model comparing the application of measurements against the occupants' responses (fig. 10), pointed out (surprisingly enough) that the occupants consider the building hotter in summer and colder in winter than Fanger's PMV/PPD based on measurements. It is possible that these results are related to the frustration of the occupants with the design and environmental aspects of the building which have other effects on the occupants' sense of comfort rather than purely environmental, such as absence of windows and lack of acoustic privacy and visual communication with the outside at the upper floors.

Figure 10: PMV according to Fanger Index and Questioners

6. FINAL CONSIDERATIONS

The unusual architectural features of the building proved to be more conceptual than really effective. The results pointed out a degree of dissatisfaction of the occupants in hot days of cloudy sky, which would definitely be aggravated under clear sky conditions. The difference between the results of Fanger's index applying the measurements against the occupants' responses highlights that the issue of environmental performance of such “special” and unusual buildings can not be understood only by means of building physics. It requires a more interdisciplinary approach including symbolism, environmental and spatial perception. Hence, the building of FAUUSP - a unique piece of the apogee of Brazilian modernism, brings lessons and questions about building's environmental performance.

The Fanger's methodology is often criticized for generalizing human responses regardless the environmental and cultural differences. Nevertheless, it is also praised by its sophisticated modelling of human physiological. Within the context of this research, it was considered as an appropriate methodology, once it allows the comparison between measurements and occupants' responses. And although the main objective of this research was not to draw design guide-lines, raising the issues related to the thermal comfort of its occupants is a preliminary step in the ultimate design approach to improve environmental conditions. Due to the iconic value of the building, such task belongs to a team work, in which architectural conservation, environmental aspects and efficient management are addressed together, in a design process supported by on site analysis and simulation tools for environmental performance.

ACKNOWLEDGEMENT

Many thanks to FAPESP and CNPq, for the support given to the two undergraduate researches from which this paper was based on. Both researches were developed by students from FAUUSP and supervised by the PhD Professor Joana Gonçalves, in 2005. Also thanks to the Professors Anésia Frota, Márcia Alucci and Denise Duarte and to the PhD and Msc students Leonardo Monteiro and Daniel Cóstola, all from FAUUSP, whose technical advises were fundamental to the success of the researches mentioned above.

REFERENCES

[1] ARTIGAS, João Batista (1998). Vilanova. Caderno de riscos originais. São Paulo, FAUUSP.[2] FANGER (1972). Thermal Comfort: analysis and applications in Environmental Engineering, New York, McGraw-Hill. [3] FROTA, Anésia (1982). Clima local e micro-clima na Cidade Universitária. Dissertação de mestrado. São Paulo, FAUUSP.[4] ISO 7726 (1998). International Standard Organization.[5] LAMBERTS, Roberto, PEREIRA, Fernando e (1997). Eficiência Energética nas Edificações. LABEEE, UFSC.[6] RUSSO, Filomena (2004). Climatic Responsive Design in Brazilian Modern Architecture. MPhil Dissertation, Cambridge, Martin Centre for Architectural e Urban Studies, Cambridge University.[7] SANCHES, Patrícia (2005). Avaliação de Conforto Térmico no Edifício da FAUUSP. Relatório Final de Iniciação Científica, FAPESP. São Paulo, FAUUSP.

Cold days: During this time, the measurements showed small temperature variations throughout the period (fig. 9). As in the hot days, the difference between air temperature and globe temperature were irrelevant, which was expected due to the reduction of solar radiation in this time of the year.


I5.2 Comparative Analysis

The comparative analyses between the results of Fanger's model comparing the application of measurements against the occupants' responses (fig. 10), pointed out (surprisingly enough) that the occupants consider the building hotter in summer and colder in winter than Fanger's PMV/PPD based on measurements. It is possible that these results are related to the frustration of the occupants with the design and environmental aspects of the building which have other effects on the occupants' sense of comfort rather than purely environmental, such as absence of windows and lack of acoustic privacy and visual communication with the outside at the upper floors.

Figure 10: PMV according to Fanger Index and Questioners

6. FINAL CONSIDERATIONS

The unusual architectural features of the building proved to be more conceptual than really effective. The results pointed out a degree of dissatisfaction of the occupants in hot days of cloudy sky, which would definitely be aggravated under clear sky conditions. The difference between the results of Fanger's index applying the measurements against the occupants' responses highlights that the issue of environmental performance of such “special” and unusual buildings can not be understood only by means of building physics. It requires a more interdisciplinary approach including symbolism, environmental and spatial perception. Hence, the building of FAUUSP - a unique piece of the apogee of Brazilian modernism, brings lessons and questions about building's environmental performance.

The Fanger's methodology is often criticized for generalizing human responses regardless the environmental and cultural differences. Nevertheless, it is also praised by its sophisticated modelling of human physiological. Within the context of this research, it was considered as an appropriate methodology, once it allows the comparison between measurements and occupants' responses. And although the main objective of this research was not to draw design guide-lines, raising the issues related to the thermal comfort of its occupants is a preliminary step in the ultimate design approach to improve environmental conditions. Due to the iconic value of the building, such task belongs to a team work, in which architectural conservation, environmental aspects and efficient management are addressed together, in a design process supported by on site analysis and simulation tools for environmental performance.

ACKNOWLEDGEMENT

Many thanks to FAPESP and CNPq, for the support given to the two undergraduate researches from which this paper was based on. Both researches were developed by students from FAUUSP and supervised by the PhD Professor Joana Gonçalves, in 2005. Also thanks to the Professors Anésia Frota, Márcia Alucci and Denise Duarte and to the PhD and Msc students Leonardo Monteiro and Daniel Cóstola, all from FAUUSP, whose technical advises were fundamental to the success of the researches mentioned above.

REFERENCES

[1] ARTIGAS, João Batista (1998). Vilanova. Caderno de riscos originais. São Paulo, FAUUSP.[2] FANGER (1972). Thermal Comfort: analysis and applications in Environmental Engineering, New York, McGraw-Hill. [3] FROTA, Anésia (1982). Clima local e micro-clima na Cidade Universitária. Dissertação de mestrado. São Paulo, FAUUSP.[4] ISO 7726 (1998). International Standard Organization.[5] LAMBERTS, Roberto, PEREIRA, Fernando e (1997). Eficiência Energética nas Edificações. LABEEE, UFSC.[6] RUSSO, Filomena (2004). Climatic Responsive Design in Brazilian Modern Architecture. MPhil Dissertation, Cambridge, Martin Centre for Architectural e Urban Studies, Cambridge University.[7] SANCHES, Patrícia (2005). Avaliação de Conforto Térmico no Edifício da FAUUSP. Relatório Final de Iniciação Científica, FAPESP. São Paulo, FAUUSP.

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fauusp, são paulo, brazil: an icon of brazilian modern ... · figure 5: studio 2. design...

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