More and more builders and developers are realizing the importance of ventilation strategies in order to achieve better indoor air quality (IAQ), especially with building envelopes that are designed to be highly energy-efficient and eco-friendly. Ventilation systems must be properly designed to perform with occupant health in mind. Beyond ventilation, a holistic approach brings added elements to the conversation about air quality and healthier living environments. Coupled with a properly-designed ventilation system, biophilic design can contribute to healthier outcomes.
The average person spends up to 90% of their time indoors. Indoor air can be, on average, up to five times more polluted than outdoor air, and, in some cases, 100s of times more polluted. In particular, IAQ is a concern for those affected by asthma and allergies, the prevalence of which the CDC indicates continues to rise in the US. Constructing healthier homes is beneficial to occupant health, as well as financial outcomes. Healthcare costs continue to grow, currently over 4% annually. Over $4.5 trillion is spent annually on healthcare in the US, which is 17.3% of the gross domestic product and equates to approximately $13,500 per person per year. Putting preventive measures into the design of mechanical systems and creating living environments with a connection to nature through biophilic design can result in healthier outcomes for Americans and contribute to lowering healthcare costs.
What is in residential indoor air? According to the Chemical Abstract Service, there are over 88,000 chemicals used in the building, home furnishings and other consumer products industries, most of which have not been tested for human safety. Many of these chemicals are toxic and known as volatile organic compounds (VOCs). VOCs are invisible, evaporate as gases into the air, settle on surfaces and contribute to poor health through continued exposure. In 2016, the Milken Institute of Public Health at George Washington University published a study that analyzed dust samples collected throughout the US to identify the top chemicals commonly found in household dust. The collected data established that people, especially children, are exposed on a daily basis to multiple chemicals from products found in dust that are linked to serious health problems. The researchers noted that exposure to small amounts of chemicals in combination can add up and lead to amplified health risks.
Proper ventilation to mitigate these chemicals in residential environments is essential. Mechanical system experts can assist with determining the proper type and size unit, as well as related elements, including necessary ductwork, filtration and (de)humidification
components. Dehumidification can be important because high levels of moisture can lead to mold and bacterial growth, affecting occupant health. Humidity can also cause excess moisture to strain ventilation systems, as well as consume higher levels of energy, adding to monthly utility bills. In addition, ventilation experts will analyze additional mitigation methods being used, such as range and bathroom exhaust fans and operable windows, that may “pierce” the tightly-sealed, built envelope and affect the ventilation system’s operation. Smart, or high-performance, fans and air purifiers can assist with automatic features that detect, cleanse and turn off. In certain regions, ventilation experts may recommend radon detecting exhaust fans, as well. Lastly, ventilation experts will determine the best filtration device for the system, analyzing the type of filter and the highest MERV rating compatible with the device.
Implementing a holistic approach to residential construction, biophilic design can add to increased IAQ and overall wellbeing. Biophilia is the human tendency to connect or interact with nature and other living things. Within the design and building industries, this movement desires to increase occupant connectivity to the natural environment through direct and indirect use of nature within the building ecosystem. For example, biophilic designs embrace living walls, indoor and outdoor gardens, ample windows, skylights and solar tubes, and water features. Phytoremediation – removal of environmental airborne toxins with the air of plants – is another benefit of biophilic design. NASA research and other studies have found that indoor plants contribute to cleaner air by removing carbon dioxide, as well as other toxins like formaldehyde, benzene and toluene. Additionally, biophilic designs tend to result in a high level of sound absorption, providing a better night’s sleep, which can reduce stress.
Clean indoor air combined with a connection to nature contributes significantly to improved overall wellbeing. Cognitive function and productivity are increased, while airborne diseases and stress are decreased. Research demonstrates that the built environment affects occupant health. Consumers are now aware; they are putting air quality and their health above all else, including energy efficiency and interior aesthetics.
