For a building to be a living space, it must comply with Virtuv’s utilitas – it should be usable and useful! Poor indoor air makes people ill, usually without any recognizable, direct connection. Indoor air quality is therefore a knock-out criterion for certification and EU taxonomy conformity can only be achieved with proof of healthy indoor air.
Text Anna-Vera Deinhammer, Sabine Huger
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Air is vital for humans. It supplies us with oxygen, helps to eliminate CO2, regulates our temperature, enables us to speak, strengthens our immune system and influences our sense of smell. Clean air is therefore crucial for our health and well-being. Vitruvius’ utilitas in building physics emphasizes the creation of functional, comfortable, healthy and sustainable spaces. This optimizes the quality of life and satisfaction of users and touches on the building physics topic of the indoor environment , which includes the aspects of indoor climate, acoustics, light, electrosmog and psychological influences. The indoor climate is in turn divided into thermal comfort and indoor air quality [1].
Breathing zones and indoor air quality
We recognize that dealing with indoor air quality has an impact on the entire human sensory system. A standard work from the visual arts is therefore a good place to start: Haus-Rucker-Co’s Breathing Zones were exhibited at the Lentos Art Museum in Linz until February 2024. The art project by the Austrian artists from the 1970s focused on spatial perception and human-environment interaction. It can serve as inspiration for interiors that take physical and psychological comfort into account. Gunter Zamp Kelp, Haus-Rucker-Co, explains that the exhibition focuses on the presence of air, an essential combination of gases for life. It is often only noticed when it smells bad, causes extreme temperatures or breathing problems. Climate control and well-tempered environments are then required to ensure our survival [2].
This way of thinking is well known to us technicians, as we define the personal experience and benefits of rooms through planning and execution. Current technical regulations reflect this and are a major step forward, especially in view of the late consideration of indoor air pollution in Austria compared to outdoor air [3]. This is astonishing, as on average 90% of life in our latitudes takes place indoors [4].
What makes us ill?
The so-called comfort parameters are used as characteristic values. These are made up of physiological parameters that cannot be influenced, e.g. age, gender, the intermediate aspects that can be influenced by user behavior, e.g. clothing, room occupancy, and the physical conditions, e.g. air temperature, relative humidity and air movement. These physical conditions can be influenced by the built environment and can cause illness if not planned or conditioned correctly [1].
Discomfort occurs when the room temperature is perceived as too cold or too warm. A related parameter in this case is the enclosing surface temperature, which determines whether we perceive nearby surfaces as comfortable or disturbing due to the exchange of radiation between the skin surface and the room’s enclosing surfaces. Glass surfaces in particular challenge our sense of comfort in this way. But that’s not all: air that is too dry damages our mucous membranes, air that is too humid prevents the body’s thermal regulation and encourages mold growth. Air movement, on the other hand, can trigger draughts.
The composition of the air is also decisive for indoor air quality. Air pollution is caused directly by the choice of construction products (building materials, equipment, surface coatings), in the course of the life cycle by user behavior (breathing, cooking, generation of unpleasant odors) and by the penetration of polluted outside air (exhaust gases, pollen, dust, radon).
Mechanical ventilation, especially in living spaces, has only a limited influence on the last aspect. Although controlled residential ventilation would be ideal for filtration and energy efficiency, user behavior shows a strong preference for opening windows individually to maintain the connection to the outside world.
Ventilation, measured by the air exchange rate, removes pollutants in buildings and protects against structural damage. The required air exchange rate, referred to as the minimum air exchange rate , depends on hygienic and building physics requirements. It is important to find an optimum that takes into account both efficient building operation and optimum indoor climate conditions, without unnecessary heat loss in winter or cooling loss in summer. A holistic view of the construction task is crucial in order to actively harmonize environmental protection and health and to maintain our quality of life.
From the clinical pictures MCS, BSI, SBS and volatile compounds VOC
Fatigue, headaches and poor concentration may indicate MCS, multiple chemical sensitivity, a health disorder caused by fragrance or solvent intolerance. [5] BRI, building related illness, refers to illnesses where a clear cause-effect relationship can be established for individuals, often caused by mold [6].
SBS, sick building syndrome, occurs when at least 25% of building occupants experience symptoms such as headaches and irritation of the eyes, nose or throat. These symptoms disappear after leaving the building, and a clear cause-and-effect relationship is often difficult to establish [1].
The choice of building products, as mentioned above, can cause VOCs, odor nuisance, irritation and symptoms due to volatile organic compounds. The problem is that these effects cannot be immediately attributed to a specific medical condition, which can lead to a frustrating search for the cause and even lead to accusations of hypochondria. It is important to avoid such situations, as chronic effects, in particular carcinogenic, mutagenic and reprotoxic effects, have also been derived from toxicological assessments.
EU and national legal framework
Regulation (EU) 2020/852, also known as the EU Taxonomy Regulation , describes in Article 14 the essential contribution to the protection objective 5 Pollution prevention and control as follows: “[…] improving the quality of air, water or soil in the areas where the economic activity takes place, while minimizing any adverse effects on human health and the environment or risks of such effects; […]”.
The Delegated Regulation (EU) 2021/2139, often referred to as the “Delegated Act on Climate Taxonomy”, supplements the aforementioned Regulation (EU) 2020/852 by way of example for the Do No Significant Harm criterion of protection objective 5 to be achieved in any case: “[…] building components and building materials with which occupants come into contact emit less than 0.06 mg of formaldehyde per m3 of building material or component after testing in accordance with the conditions set out in Annex XVII to Regulation (EC) No. 1907/2006 and less than 0,001 mg of other carcinogenic volatile organic compounds of categories 1A and 1B per m3 of building material or component after testing according to CEN/EN 16516 or ISO 16000-3:2011 or other equivalent standardized test conditions and methods […]”.
OIB Guidelines 3 “Hygiene, Health and Environmental Protection”, 2023 edition, regulates the requirements for ventilation and heating in Austria. Chapter 10.1.1 states, among other things, that sufficient ventilation directly to the outside must be ensured for common rooms and sanitary facilities. Mechanical ventilation can only replace this direct air exchange if it allows a sufficient air exchange rate. Glazed loggias or conservatories in front are permitted for recreation rooms if they are assigned to the respective living and operating unit and the windows, doors, etc. can be opened. Chapter 10.1.2 adds that rooms with a particularly high expected air humidity production – e.g. kitchens, bathrooms – must be ventilated naturally or mechanically.
The regulations for the installation of fireplaces state in section 10.1.3 that the air exchange rate must be ensured in accordance with their design. Room air-dependent combustion systems require boiler rooms which must have a minimum cross-sectional area of 400 cm² for the supply air duct from outside.
Bibliography
[1] Künzel, H.: Skriptum Raumklima. Stuttgart: Master Online: Building Physics.
[2] kultur-online: House-Rucker-Co: Breathing zone. 16.10.2023, available at https://kultur-online. net/inhalt/haus-rucker-co-atemzonen, checked on 12.02.2024.
[3] Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and Technology: Richtlinie zur Bewertung der Luftqualität von Innenräumen, available at https://www.bmk.gv.at/themen/ klima_umwelt/luft/innenraum/rl_luftqualitaet. html, checked on 12.02.2024.
[4] Ökokauf Wien: Indoor air quality, available at https://www.wien.gv.at/umweltschutz/oeko- kauf/pdf/innenraum.pdf, checked on 12.02.2024.
[5] Bartha, L.; et al: Multiple Chemical Sensitivity. A 1999 consensus. In: Archives of Environmental Health: An International Journal, 54:3, 147 – 149.
[6] Federal Environment Agency: Sick in a “sick-making” building – the sick building syndrome. 07.11.2017, available at https://www.umweltbundesamt.de/themen/gesundheit/belastung-desmenschen-ermitteln/umweltmedizin/sick-building-syndrom, checked on 12.02.2024.
