Acoustic Classification of Buildings: Impact of Acoustic Performances of a High Energy-Efficient Building on Quality and Sustainability Indicators
According to similar experiences of other countries, also Italian standards are defining procedures about acoustic classification of buildings, aiming at the determination of indoor acoustic comfort. Acoustic parameters influence building quality in different ways and amounts: the aim of the paper is to attest acoustic performances of buildings, taking into account different noise sources and people expectations. A voluntary certification model was proposed to assess indoor overall quality, which includes a specific Acoustic Performance index (AP) concerning human protection against noise into buildings. According to existing standards, noise measurements were carried out in order to assess acoustic performances of walls, facades, floors and systems in a high energy-efficient multifamily building as a case study. The paper shows a feasible approach to perform indoor acoustic comfort and to support sustainable buildings: a comparison was carried out between impact of acoustic performances on proposed assessment of building quality and on certification of building environmental sustainability introduced by law at regional level.
SOUND INSULATION OF IDENTICAL BUILDING ELEMENTS IN DIFFERENT BUILDINGS
Based on practical experience and experimental investigations, the acoustic performance of building materials and components may vary considerably in different buildings and even compared to the estimation obtained by simulation. The paper focuses on typical questions of building acoustics, such as: the accuracy of the calculation model implemented in order to estimate the sound insulation of building elements; the difference between the predicted value and the actual result of “in situ” sound insulation measurements; the different acoustic performance of identical partitions, although built using the same materials and installation methods; the reproducibility of measurements and the influence of instruments on measurement results, for the same test conditions; any difficulties due to size and irregular shape of the rooms subjected to acoustic measurements. Sound insulation of partitions was assessed by field measurements in residential buildings, according to international standards. Measurements were also performed by different systems to consider reproducibility, measurement uncertainty and instrumental error. Results were analysed and compared, taking into account also predictions based on technical standards. The aim of the paper is to provide a useful contribution to the addressed topics.
Reversible low solar heat gain windows for energy savings
Abstract Summer cooling loads in buildings can be reduced with windows of low solar heat gain coefficients (SHGC). Such windows are often double glazed with the exterior pane tinted or selectively absorbing. They reject part of the absorbed solar radiation to the environment, reducing the solar heat gain. This effect is undesirable in the cold season. However, the same window installed in reverse, i.e. turned by 180°, has a significantly higher SHGC. Thus, windows that can be reversed according to the season will both reduce summer heat gains and collect much of the beneficial solar radiation in winter. This paper investigates the energy savings achievable by reversing equator-facing windows for the duration of the cold season as opposed to leaving them in the “summer position”. Candidate climates in which these savings may be significant are identified. By means of a computer simulation, seasonal energy savings are predicted for a model room with reversible, low SHGC, windows. The results indicate that for suitable climates, significant savings are achievable.