Indoor Environmental Air Quality and How COVID-19 Pandemic Affected Our IAQ

Chapter 10 – Indoor Environmental Quality: Acoustics and Indoor Air

In this chapter we learned about the location of open offices in order for them to get the minimal amount of sound transmission and how to meet client needs for speech privacy. It also discussed the impacts of LEED on acoustics and indoor air quality, as well as the importance of good indoor air quality to health, safety, and welfare of building occupants. The chapter also specified sustainable materials that support good indoor air quality and how to identify acoustical needs in a space and how to accomplish acoustic separation goals.

Acoustics

We learned that acoustics is the study of sound and as designer it is important for us to understand how it moves through a space and the certain materials and finishes used within said space. It is also our job to be aware of and expect possible sources of noise – unwanted sound. As humans we hear the sound waves that are created when something or someone makes noise. These sound waves have the ability to be refracted reflected, diffracted, and diffused. When sound is reflected it the sound that is returned from hitting a surface. When sound is reflected it means that it is mirrored back into the space. Sound waves, similar to light waves, can be bent and their speed changed. Diffraction is described in this chapter as the capability of a sound wave to bend around a barrier and diffusion as occurring when the wave comes in contact with an uneven surface and produces an odd sound distribution.

It was discussed that noise is any unwanted sound, but these unwanted sound waves are able to be absorbed. Take a partition, for example, when sound passes through it, the partition absorbs the sound waves attempting to move through it. All materials absorb sound. Materials are rated with a noise-reduction coefficient where the average of a material’s absorption coefficient is 250, 500, 1000, and 2000 hertz. They also all have a sound-transmission class which refers to the capability of a material to absorb sound and is often in accordance with transmission loss, which is a single number that describes sound transmission for typical human hearing. All of this is important for an interior designer to understand because without these numbers it is nearly impossible to create a space for both sound and quiet.

When looking at a physical space and choosing how to communicate it to people, sound plays a big role in materials and furniture used. Sound waves travel through walls studs with almost no difficulty, so breaking the path that sound travels on can prevent the transmission of sound. Take the wall studs for example. When you start to stagger them, the transfer of sound is redirected. It is important to note, however, that a designer needs to always keep the room volume low when low reverberation times are desired. When looking at an office space, a designer wants to create an open-airy feeling, but that is difficult to do when you consider how sound will travel throughout the space. Certain noise reduction solutions can start by controlling noise at the site, in it path, or near the receiving end. With open offices, partitions are used to reduce unwanted sound between workstations and are best used in layouts that are combined with sound-masking white noise and acoustical ceiling tiles.

An Approach to Green Acoustics and Selections Criteria

When thinking as an interior designer, it is important to go for an integrated design approach that will achieve both sustainability goals and acoustical needs. This starts with the selection of the site because a building needs to be located away from high noise areas, however, if that is not possible then noise can be combated with sound control measures and others. Specific acoustical solutions include ceiling tiles, carpeting, and insulation made of recycled content. All of this emphasizes the importance of the selection of our materials.

It is important to assess the life-expectancy of a material. This involves looking at aspects such as
material extraction, where it was made, transportation costs, how long it lasts, and what happens to it when it is no longer usable. Embodied energy is the amount of energy used to create a material from extraction through production and installation and eventually disposal, and it's supposed to take many of these previous factors into consideration.

Effects of COVID-19 Pandemic on our Air Quality

Throughout 2020 the world was confined in their homes, rarely going outside, and dealing with their fresh ventilated air. However, not everyone had the luxury to breath in clean air each day they spent indoors. With isolation being the main way to prevent the spread of COVID-19, homes improper ventilation was exposed to causing other health problems like irritation, physical symptoms, respiratory and heart diseases, and cancer. The situation becomes even more serious if the air quality of the home is bad to begin with. Due to the fact that people spend the majority of their time indoors, their exposure to poor indoor air quality is increased.

However, homeowners can improve their indoor air quality by increasing their ventilation with outdoor air and air filtration systems. They can even open windows and doors to allow fresh air inside. COVID-19, in a way, actually improved the indoor air quality of the majority of our buildings. With systems and machines, like air purifiers and humidifiers, air-borne germs were killed faster, and the air was cleaned quicker. These were especially seen in dentist offices when patients were sitting for hours with their mouths open and the dentist breathing over them.