Loading...
Publication
Simulações de conforto térmico de uma edificação histórica utilizando os softwares Rhinoceros 3D e Grasshopper: caso de estudo do Museu Nacional Grão Vasco
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 5.08 MB | Adobe PDF |
Authors
Abstract(s)
A conservação de edificações históricas é fundamental para preservar a cultura entre
gerações. Nos novos edifícios, o uso de software de simulação tornou-se comum,
permitindo projetos mais eficientes em termos energéticos e de conforto para os
utilizadores. No entanto, para edifícios existentes, esses programas ainda não são
amplamente utilizados, apesar da crescente necessidade de reabilitação.
Foi caracterizado o desempenho atual do edifício e analisados cenários de
intervenções de reabilitação, designadamente a substituição dos envidraçados
originais (vidro simples incolor) por vidro simples laminado e vidro duplo de baixa
emissividade. O vidro duplo de baixa emissividade apresentou o melhor desempenho,
reduzindo a temperatura média interna e diminuindo significativamente os períodos
de desconforto térmico por sobreaquecimento durante o período de verão,
contribuindo tanto para o conforto dos ocupantes, quanto para a preservação do
acervo.
Outro aspeto analisado no modelo foi o impacto da estratégia de ventilação, através
de alterações no parâmetro de Renovações Por Hora (RPH). Testaram-se três
cenários: 1 RPH constante ao longo do dia, 2 RPH constantes ao longo do dia e, por
fim, um cenário com variação entre 1 e 2 RPH ao longo do dia. O cenário com 2 RPH
constantes apresentou a maior redução da temperatura média interna e uma
considerável redução no período de desconforto por sobreaquecimento. O impacto da
ventilação na simulação mostrou ter um maior impacto do que a troca dos
envidraçados. Ainda assim também foram simuladas combinações dos diferentes
envidraçados com os cenários de ventilação.
Por fim, comparam-se os valores obtidos nas simulações com os limites de
temperatura indicados para a conservação dos acervos do museu estabelecidos pela
norma da ASHRAE (2017). Tanto nas simulações como nas medições reais verificou se que, no período analisado (junho a setembro), as temperaturas excederam os limites
recomendados pela norma em mais de 60% do tempo, tanto para a situação inicial
como após as propostas de intervenção.
The conservation of historic buildings is crucial to preserving culture across generations. In new buildings, the use of simulation software has become common, allowing for more energy-efficient designs that enhance user comfort. However, for existing buildings, these programs are still not widely used, despite the growing need for rehabilitation. The current performance of the building was characterized, and rehabilitation intervention scenarios were analyzed, specifically the replacement of the original glazing (colorless single-glass) with laminated single glass and low-emissivity double glazing. The low-emissivity double glazing performed the best, reducing the average internal temperature and significantly decreasing periods of thermal discomfort due to overheating during the summer, contributing both to occupant comfort and the preservation of the collection. Another aspect analyzed in the model was the impact of the ventilation strategy, through changes in the Air Changes per Hour (ACH) parameter. Three scenarios were tested: 1 ACH constant throughout the day, 2 ACH constant throughout the day, and finally, a scenario with a variation between 1 and 2 ACH throughout the day. The scenario with a constant 2 ACH showed the greatest reduction in average internal temperature and a significant decrease in the period of overheating discomfort. The impact of ventilation in the simulation proved to have a greater effect than the glazing replacement. Nonetheless, combinations of different glazing types with ventilation scenarios were also simulated. Finally, the values obtained in the simulations were compared with the temperature limits set for the preservation of museum collections according to the ASHRAE (2017) standard. Both the simulations and real measurements showed that, during the analyzed period (June to September), the temperatures exceeded the recommended limits by the standard for more than 60% of the time, both in the initial situation and after the proposed interventions.
The conservation of historic buildings is crucial to preserving culture across generations. In new buildings, the use of simulation software has become common, allowing for more energy-efficient designs that enhance user comfort. However, for existing buildings, these programs are still not widely used, despite the growing need for rehabilitation. The current performance of the building was characterized, and rehabilitation intervention scenarios were analyzed, specifically the replacement of the original glazing (colorless single-glass) with laminated single glass and low-emissivity double glazing. The low-emissivity double glazing performed the best, reducing the average internal temperature and significantly decreasing periods of thermal discomfort due to overheating during the summer, contributing both to occupant comfort and the preservation of the collection. Another aspect analyzed in the model was the impact of the ventilation strategy, through changes in the Air Changes per Hour (ACH) parameter. Three scenarios were tested: 1 ACH constant throughout the day, 2 ACH constant throughout the day, and finally, a scenario with a variation between 1 and 2 ACH throughout the day. The scenario with a constant 2 ACH showed the greatest reduction in average internal temperature and a significant decrease in the period of overheating discomfort. The impact of ventilation in the simulation proved to have a greater effect than the glazing replacement. Nonetheless, combinations of different glazing types with ventilation scenarios were also simulated. Finally, the values obtained in the simulations were compared with the temperature limits set for the preservation of museum collections according to the ASHRAE (2017) standard. Both the simulations and real measurements showed that, during the analyzed period (June to September), the temperatures exceeded the recommended limits by the standard for more than 60% of the time, both in the initial situation and after the proposed interventions.
Description
Keywords
Conforto térmico Simulações computacionais Edifício histórico Thermal comfort Computational simulations Historical building