Green design and smart technology for acoustic comfort
Buildings being made for people to live in and must take into account human comfort while being designed. As a matter of fact, comfortable indoor environments increase occupants’ productivity, health and overall well-being.
In a serie of four articles, we will look into different performance indicators, such as visual comfort, acoustic comfort, thermal comfort and air quality, that can be monitored in order to promote occupant's overall well being, health and performance in indoor spaces.
Design Metric Series
Design Metric # 2 - Acoustics
Design Metric # 2 - Acoustics
You can find our previous article about visual comfort here.
Today, half of the population lives in cities that are exhausted by noise-producing activities, equipments and transport. Meanwhile, our perception of sound is inherent to our capacity to interact with each other, communicate and our sense of space.
“ According to the World Health Organisation (WHO), noise-induced hearing impairment is the most prevalent irreversible occupational hazard and it is estimated that 120 million people worldwide have disabling hearing problems.”
So how can green design and smart technology improve acoustic comfort ?
The notion of acoustic comfort is subjective to the individual as well as on the quality and the intensity produced by the noise sources. This quality and the comfort of indoors have an influence on the quality of work, sleep and the relationships between people. When the acoustic comfort is poor, we can quickly observe negative effects such as decreased productivity, social conflicts and health issues.
There are three different types of noise sources in a building :
Airborne noise, sounds vehiculed by the air such as voices, music and transport.
Contact induced noise born from a contact with a building element as footsteps, tools and falls.
Equipment noise as air conditioners, heating systems, elevator...
To avoid poor acoustic comfort, buildings should be designed and improved with green strategies and smart technologies. As a general rule, there are three principal methods to achieve effective acoustic comfort: absorbing noise, blocking noise and covering noise.
Green design strategies create acoustic comfort
Green design in its essence about designing spaces for people to thrive in. In that sense, catering to acoustic comfort is essential for us to fulfill our activities at work and at home.
Over the past decade, startups and corporations have been adopting an open space style for their company environment. While open spaces offer immense possibilities for collaboration, they also can lack the privacy needed for tasks requiring concentration levels. This is particularly true when it comes to noise protection and the ability to stay undisturbed by neighboring conversations.
Distraction arising from noise is actually one of the principal causes of dissatisfaction in the workplace. Cubicle partitions can be designed to block sound in an office space. Their size, height and materials will determine their sound proof performance.
There is a common perception that high cubicle partitions would do a better job in protecting against noise,providing better privacy and fewer distractions. But in reality, research shows that higher cubicle partitions block standing line of sight but provide small amounts of additional acoustical shielding, according to GSA Public Buildings Service. As a matter of fact, this increase in ‘visual privacy’ is illusory and “encourages people to talk louder because they think they have more privacy. Unfortunately, there may be less privacy and more disruption.”
“At work, performance drops by 66% when exposed to distracting noise.” - World Green Building Council
When it comes to outdoor pollution, traffic is the biggest cause of noise and air pollution. When designing buildings and outdoor spaces in highly congested areas, vegetation can be a way to block traffic noise, minimize disturbances while improving air quality. To be effective, a vegetation barrier should be implanted as close as possible to noise source: the road. In addition, vegetation must be carefully chosen to most effectively halt noise. As an indicator, foliage with large leaves is the most efficient to stop sound.
Smart technology advance acoustic comfort
Smart devices measure, monitor and improve acoustic comfort in real time.
For example, Bosch's new Ambient Sensor measures environmental conditions such as air quality, light and noise intensity with the building's HVAC and lighting systems. To do so, it uses “integrated sensors to determine the indoor air quality by VOC analysis (volatile organic compounds), and measuring temperature, relative humidity, barometric pressure, and light and noise levels.” The system can be operated remotely or integrated in the building system for better data measurement and improvement.
Also, designers may want to add sound masking to their spaces as a cover strategy. Sound masking is a technology which produces sound at the same frequency as human speech as well as noise from common activities.This technique consists of speakers which controllably raise the background sound. Therefore, any noise below the engineered sound level is covered up. According to Cambridge Sound Management “by adding sound masking to a workplace, conversations are notably less intelligible or noticeable, and thus less distracting. The workplace becomes more comfortable, private, and productive”.
Follow us to discover other performance indicators, such as air quality, later this month.
This article is part of a series of four articles on design metrics for human well-being, health and performance. Find out which other metrics contribute to a positive human experience in indoor environments.