We spend 90 per cent of our time indoors in Denmark. Yet the quality of indoor environment (IEQ) is a topic surrounded by claims and anecdotal evidence, such as that it is expensive to ensure a good quality. Here are some thoughts on the topic from Professor Pawel Wargocki from the International Centre for Indoor Environment and Energy at DTU Sustain.
Can we build energy efficiently while also ensuring a high IEQ?
Absolutely, yes. Constructing energy-efficient buildings doesn’t have to be an obstacle to creating a good indoor climate. It’s a myth that all new climate-friendly buildings end up being too airtight and therefore have a poor quality of indoor environment (IEQ). Conversely, not all older buildings have high quality.
For example, we have been studying the IEQ at DTU’s campus in Lyngby, in both the 50-60-year-old buildings and in the new buildings that are less than ten years old. We have conducted objective measurements and surveys among buildings’ users, which means that we have both performed physicochemical measurements and asked users of the buildings to rate IEQ. So far, we have not found any strong association with building age.
Is it expensive to ensure a healthy indoor environment?
Absolutely not! If you renovate a building or build a completely new one, ensuring high IEQ is not expensive, as long as you factor in the solutions already during the planning stage.
When we construct new buildings in Denmark or perform major renovations, Danish Building Regulations clearly define the requirements for the indoor environment. They include provisions for adequate building ventilation, building materials that do not pollute indoor air, air quality, satisfactory light, comfortable temperature conditions in both summer and winter and optimal acoustic conditions.
Indoor environment enhancements and improvements may be expensive in buildings that already have problems, such as is the case with PCB and asbestos.
What is most often overlooked about IEQ?
Most people know that temperature, air quality, light, and noise are the most essential components of IEQ. They cannot be compromised to secure well-being.
There are also other factors. For example, only a few people may be aware of how much our well-being is increased when we have contact with nature. Studies have shown improvements in well-being among the buildings’ users when there is a view of natural surroundings, such as when you can see trees or a green area while you are inside. If impossible, you can have indirect access to nature like potted plants. Part of the natural experience is sufficient access and exposure to daylight. The technical term for ensuring access to nature in a building is a so-called ‘biophilic design.’ Access to nature is not part of the conventional view of IEQ yet it makes sense to be aware of this element to improve well-being indoors.
Another overlooked element is users’ influence and control of IEQ. Our ability to regulate, for example, the temperature or air quality, open windows, etc., when needed, is also essential to our well-being.
However, the biophilic design and providing building occupants with the methods to control IEQ will not compensate for the poor IEQ if the essential parameters ensuring high quality of thermal, acoustic, luminous environments and indoor air quality are not at the correct levels.
How much can we solve by just opening the window?
Window-opening often can be a good solution if there is no mechanical ventilation. For example, in classrooms, it can help improve ventilation and thus air quality, often demonstrated by the carbon dioxide (CO2) content in the air, CO2 being exhaled by building occupants. So, besides the psychological effect mentioned above, windows can help in specific situations, such as bedrooms without mechanical ventilation; our research has shown that fresh air when the window is left ajar gives a better quality of sleep.
However, we open windows mostly because it is too hot and rarely because the indoor air quality is poor due to, for example, odors from cooking, high humidity, etc. Window opening can be restricted when it results in noise and draught. It can also draw in polluted air from outside that many of us are unaware of. During hot and cold periods, open windows may cause problems with the temperature. So, the effect of opening a window depends on many factors and is not a secure solution to avoid exposure to pollutants. Consequently, it should not be considered a universal solution for all IEQ problems. Mechanical ventilation, on the contrary, is such a solution.
Is IEQ under-prioritized, observing that so many schools in Denmark struggle with it?
Although we generally have good IEQ management in place in many buildings in Denmark, some buildings and locations are lagging. This is puzzling because, for many years, research has systematically documented that a poor IEQ in workplaces reduces productivity and negatively impacts learning in schools. It also leads to increased absence due to illness, not to mention poor sleep quality as the least.
A poor IEQ consequently leads to significant economic losses. This was particularly evident during the pandemic, which showed that we were unprepared to handle this situation with technical solutions, including mechanical ventilation in buildings. Had we been prepared, the losses would have been much smaller.
As some effects of poor indoor air quality can be delayed and are not observed at once, it may be challenging to understand the necessity of doing something today. For example, we cannot estimate economic losses today due to children’s reduced academic development and challenged health in classrooms with poor IEQ. But they will undoubtedly appear in the future. And it will be too late to make any corrections or amendments.
I also believe that the economy comes into play when nothing is done with IEQ year after year. Again, the misperception that it is costly to make minor corrections and regular maintenance will result in the problems growing and much more expensive actions in the future.
What knowledge do we lack?
It could be interesting to focus on the positive effects that indoor environmental quality can have on our health and well-being. We should learn more about how the quality of the indoor environment can support our physical and mental health and perhaps make us more 'resilient' and better prepared for potential challenges. For example, are there any connections between the components of the indoor environment and our immune and neural systems that we could exploit so that we become stronger even if we are indoors?
This approach is called regenerative design and salutogenesis, where we study the origins of health and focus on factors that support human health and well-being rather than on factors that cause diseases and discomfort (pathogenesis).
Our research group examines connections between the indoor environment, its components, human responses, and mental health. We also examine how the different components interact and what the consequences of these interactions are. Are we, for example, more affected by air quality if it is more noisy? Our research focuses on the user experience and feelings, so it is not merely about measurements. For example, different temperatures can be experienced very differently by various people.
The most important for us is that we have people at the center of our research.
