Indoor Environmental Quality parameters

In the previous article, we learned about the importance of Ergonomics and its impact on the person’s health and productivity. In this article, we will focus on how our environmental factors or conditions in our immediate environment affect us.

Since humans adapt themselves easily to the condition perception of our surrounding conditions in terms of temperature, noise, air quality, lighting levels, we don’t realise their gradual adverse impact on us. In the given era where comfort fuels productivity and health, it becomes important to understand the role of these parameters often termed as ‘indoor environmental quality parameters’, as a single group on occupant’s overall wellbeing.

So, how do all these quality parameters affect us?

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Indoor Air Quality

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Air in our indoor or outdoor environment is just a mixture of gases, predominantly Nitrogen and Oxygen, along with other components like CO2, water vapour and a nominal amount of other gases. However, it also contains pollutants in the form of particulate matter (PM), Volatile organic compounds (Formaldehyde, Toluene, Benzene and others), which are emitted due to anthropogenic activities such as exhaust from vehicles or factories or through natural events at times. Another type of pollutant is microbes, while most of them are not harmful to us and are required to maintain our immunity but some of them can be really harmful.

Thus, it becomes critical for the breathable air to have a balanced composition by maintaining air constituents within the permissible limits as defined by local and international standards or guidelines.

Once this desired equilibrium is disturbed, it can lead to acute or chronic respiratory issues depending upon the occupant’s underlying health conditions, daily activities and severity of the exposure.

In our Indoor environment, there is

Thermal comfort:

Thermal comfort is about being able to feel comfortable with the temperature, humidity and air movement as per the local weather conditions. It is also dependent on the clothings, activities, age & gender of the person. We can say it as a ‘state of mind that expresses satisfaction with the surrounding thermal environment’.

While working from home, we primarily use fans and air conditioners to achieve a thermally comfortable environment. On one hand, while fans may enhance comfort by providing air circulation, they may not help to balance humidity or temperature. On the other hand, the air conditioner may help to achieve desired temperature and humidity but may lead to thermal shock (the sudden change in temperature while moving between warmer zones like kitchen, bathrooms, to cooler zones or vice versa). Hence, finding the right balance between all these parameters is important.

If an occupant is working in warm or cold conditions for a prolonged period of time, it can result in reduced cognitive ability and hence, productivity. Research has also proved that thermal discomfort causes restlessness and distraction during task performance.

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Acoustics comfort

Our outdoor spaces are mostly crowded, noisy and streets are brimming with activities year-round. This prompts us to find peace at home, places of worship, etc., as they are relatively quiet and are away from all the hustle-bustle.

Since we are used to spending more time at home and getting engaged in the activities which require focus, it is just no more about outdoor noise. A person may get distracted from indoor noise sources like equipment (vacuum cleaners, TV etc.), making it difficult to focus on activities like working, studying or making a call with colleagues. Moreover, the privacy of speech also becomes important if multiple family members are working from home. It is not just noise and privacy, but also ‘overall acoustics quality’ which includes echo, speech clarity etc., resulting in a sense of quietness, calmness and allows us to focus for a long duration.

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Being exposed to noisy conditions for the long term can lead to mental fatigue, sleep disorder and inability to focus. Hence it becomes important to give attention to the largely neglected acoustics aspect of homes.

Visual comfort

Since our childhood, we have been told by our parents to read or perform tasks in well-lit conditions and to sit far away from the TV screen. Hence, unconsciously we are somewhat aware of the impact of lighting levels on our health. In technical terms, visual comfort is a subjective reaction to the quantity and quality of light within any given space at a given time.

As the human eye is continuously adjusting to the surrounding light levels, a drastic variation in terms of brightness or contrast can result in eye stress and fatigue. The impact can depend on the following factors — the type of light (dim or bright), time of exposure (long or short) and the age of a person, as old aged people are more sensitive towards the lighting levels.

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In this modern era, we are spending a lot more time on screens and in artificial light, unlike our previous generations. When we are continuously looking at the device screen or reading in poor light conditions (too bright, dull or contrasting) it hurts our eyes and may affect our ability to focus. Also, if the artificial lights are of substandard quality, they may affect how we perceive colours. Hence we need to be careful about the adequate lighting levels around us as the lack of it might affect our vision.

Within our ability to control parameters causing us discomfort, we try to maximise our comfort. But, they may not be sufficient or may not yield desired results. In the next few articles, we will explore these topics.