The influence of passive measures on the highly demanding room climate requirements of a museum building in terms of sustainability

Abstract

In the exhibition space of a museum, a compromise between the requirements for the preservation of cultural goods and thermal comfort criteria for visitors has to be applied. Such a high level of control without allowing fluctuations in temperature and relative humidity poses a big challenge to the air conditioning systems to maintain these very specific hygrothermal conditions.
This study presents a simulation-based parametric study of passive measures implemented to reduce the energy demand and thereby also the environmental impact of the building. The changes were limited to the interior walls and surfaces, keeping the main type of construction of the investigated reference building intact. The effect of thermal mass by wall thickness and moisture buffering capacity of clay plaster were assessed.
The simulation results showed that the biggest increase of thermal mass could lower the cooling demand by 1.8 % while the thickest layer of clay plaster reduced the dehumidification demand by nearly 2 %. These effects confirmed the general hypothesis but the improvement was rather minor. In terms of life cycle assessment, the applied changes amortized in less than two years due to the low initial environmental impact of the measures. By implementing a specific climate risk assessment method it was possible to investigate the impact of changed setpoints while still maintaining conservation requirements. This resulted in a reduction of the cooling demand by a third. In general, a critical review of the current standards and practices on museum air conditioning and individual risk assessment could lead to a considerable mitigation of environmental impacts currently caused by museums.

Popular Abstract

In 2018 the building and construction sector caused 36% of final energy use and 39% of energy-related CO2 emissions worldwide, being thereby the sector with the biggest impact in emissions of greenhouse gases. Museum buildings are often of high architectural value and are therefore being operated for a much longer time than other types of buildings. Over their lifespan, this results in an even higher environmental impact of their energy consumption.
The main purpose of a museum is to conserve and exhibit human heritage. Some of these invaluable exhibits are extremely sensitive to changes in temperature or humidity. This results in very strict requirements for the interior climate. In the exhibition space of a museum, a compromise between the requirements for the preservation of cultural goods and thermal comfort criteria for visitors has to be applied. Such a high level of control without allowing fluctuations in temperature and relative humidity poses a big challenge to the air conditioning systems to maintain these very specific hygrothermal conditions.
This study presents a simulation-based parametric study of passive measures implemented to reduce the energy demand and thereby also the environmental impact of the building. The changes were limited to the interior walls and surfaces, keeping the main type of construction of the investigated reference building untouched. The effect of thermal mass by wall thickness and moisture buffering capacity of clay plaster were assessed. Thermal mass is a building’s ability to store heat. High thermal mass can have a buffering effect on temperature fluctuations and thereby lead to a more constant temperature level on the interior. By using hygroscopic materials similar on the interior surfaces a similar effect can be achieved for changes in relative humidity. Such materials can accumulate and release water through sorption processes. To investigate the effect of thermal mass, different interior wall thicknesses were assessed. The effect of moisture buffering was assessed by adding different thicknesses of clay plaster to the interior walls.
The simulation results showed that the biggest increase of thermal mass could lower the cooling demand by 1.8 % while the thickest layer of clay plaster reduced the dehumidification demand by nearly 2 %. These effects confirmed the general hypothesis, but the improvement was rather minor.
The life cycle assessment showed, that the passive measures had a positive effect on the building’s global warming potential. While the additional materials needed for thermal mass and hygroscopic properties had a negative effect on the environmental impact of the construction, the reduction on the energy demand made up for it within two years. By implementing a specific climate risk assessment method, it was possible to investigate the impact of changed setpoints while still maintaining conservation requirements. In this method four well researched objects that represent a mixed collection were chosen. The influence of changes in temperature and relative humidity on these specific objects were analysed to draw conclusions on the necessary level of control. This more detailed approach allowed a lower level of control and thereby a reduction of the cooling demand by a third. In general, a critical review of the current standards and practices on museum air conditioning and individual risk assessment could lead to a considerable mitigation of environmental impacts currently caused by museums.

• author: Jost, Jasmin
• supervisor: Saqib Javed
• organization: Division of Energy and Building Design; Department of Architecture and Built Environment
• course: AEBM01 20211
• year: 2021
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: museum, museum climate, conservation requirements, climate risk assessment, indoor environment, thermal comfort, thermal mass, moisture buffering, hygroscopic materials, life cycle assessment (LCA)
• language: English
• id: 9066271
• date added to LUP: 2021-09-29 15:17:00
• date last changed: 2021-09-29 15:17:00