INDOOR AIR QUALITY
What is INDOOR AIR QUALITY?
When talking about « fresh, clean air » images that come to mind are often nature related: an alpine landscape, a seaside breeze, a forest after the rain. So how does this translate when inside a building today?
The INDOOR AIR QUALITY makes reference to the right amount of fresh air provided according to occupation rate and type of activity and also has three dimensions:
The physiological aspect of INDOOR AIR COMFORT:
We inhale and exhale an average of 12,000 litres of air per day. Our ability to assess the quality of this air generally involves two senses: olfaction (smell) and the common chemical sense (the ability to sense irritants)
The physical aspect of INDOOR AIR COMFORT:
The effects of indoor air pollutans (like gases and vapours) on perceived air quality and health is influenced by indoor environmental parameters such as ventilation rate, air velocity, temperature, humidity, activities taking place and the frequency and duration of exposure.
The socio physiological aspect of INDOOR AIR COMFORT:
Several industries have devoted considerable resources to the understanding of this dimension. Most of the efforts has been focused on pollutants and unpleasant odours, mainly with regards to their impact at work and school.
Sources of indoor pollution:
• Outdoor sources (traffic and industry)
• Occupant-related activities and products (tobacco smoke, cleaning products, personal care, printers)
• Building finishes and furnishings (plywood, paint, furniture, floor/wall coverings)
• Ventilation system components (filters, ducts, humidifiers)
What are the indoor air polluants?
The different indoor pollutants can be classified into two main categories (primary pollutants):
• Physico-chemical pollutants – gases and vapors (inorganic and organic) and particulate matter, such as carbon dioxide, carbon monoxide, VOCs, particles, fibers, ozone, etc.
• Biological pollutants – microbiological (dust) particles floating in the air that originate from viruses, bacteria, mold, mites, insects, birds, mammals and pollen. These include allergens, endotoxins and mold (which can be both allergenic and toxic).
And secondary emissions:
• Products present in a building can emit substances (particles and/or gases) that originate from the product itself (primary emissions), that are caused by coming into contact with other products, or that arise during the in-use phase of the product itself (secondary emissions).
Human exposure to indoor air pollutants is influenced by factors such as the ventilation rate within a building, air velocity, temperature, relative humidity, the activities taking place, and the frequency and duration of exposure.
The first step in controlling indoor air pollution is therefore to remove emissions of primary and secondary pollutants at source. This can be achieved by paying attention to the ingredients of materials brought into any living or working space and, where possible, choosing healthier alternatives (formaldehyde free, natural products).
DID YOU KNOW?
Research has shown that poor air quality (and elevated temperatures) consistently lowers office workers’ performance by up to 10%, on measures such as typing speed.
DID YOU KNOW?
Most people feel that air quality is important to their day-to-day well-being. In one of a Danish survey, when questioned on the words that describe factors contributing to comfort, 21% of responses related to ‘fresh/clean air and smell’, just after ‘light, sun’ (46%) and ‘temperature, warmth’ (35 %)
comfort with indoor environmental quality in Danish housing. Building and Environment, 2012, 50:
What contributes to INDOOR AIR COMFORT?
Historically, good air quality was associated with the absence of pollutants that could affect people’s health. However, today other parameters appear when assessing indoor air quality, which are also important for the occupants’ comfort and wellbeing: the absence of bad smells, sensory irritations and stuffiness (headache and fatigue).
INDOOR AIR COMFORT is determined by:
• Indoor air quality
• Fresh air supply
• Absence of internal pollutants
• Control of odors
What’s clear, is that only with constant supply of clean fresh air (free from pollutants and bad odour) we’re more productive, happier and experience fewer health issues. Although there is no evidence that unpleasant odours are linked to adverse health effects, scientific research shows that they can cause mental distraction and may have a negative impact on mood and stress levels. The best way of improving indoor air quality is to work to reduce pollution from source, while improving ventilation, and purifying the air.
Designing for INDOOR AIR QUALITY?
INDOOR AIR COMFORT is a key element in the design and planning process of any new building or renovation project. The first step in controlling indoor air pollution is in removing or minimizing emissions of primary and secondary pollutants at source.
An optimum flow of fresh air requires a certain number of air changes per hour, depending on room size, occupancy levels, type of activity. Automated ventilation systems are the most efficient, but natural ventilation (essentially, manual or automated window opening) removes the need for ducting, with initial cost savings, lower running costs and health
Manual ventilation also delivers the psychological benefits of putting the occupant in control and making a connection to the outside world. Of course, it depends on the environment of the building (busy road). Hybrid ventilation is growing in popularity: natural ventilation in mid-season and mechanical in more extreme weather conditions.
Filtering incoming and outgoing air helps remove harmful particulates. However, air filters need to be maintained to prevent the ventilation system itself from becoming a source of pollution, rather than the solution.
Active scavenging materials
MULTI COMFORT buildings ensure plentiful fresh air supply, by using innovative products to minimize CO2 and VOC levels and create a healthier place for people to live, learn and work in. Healthier buildings have a big impact on wellbeing and productivity.
Good design, proper ventilation (mechanical and natural ventilation) and specification of the right building materials are essential to increase the supply of fresh air in a building, and to reduce our exposure to indoor pollutants and odors.
Modern construction materials have been specifically developed to actively remove polluting and harmful VOCs (volatile organic compounds) from indoor air.
Active scavenging materials
MULTI COMFORT buildings keep outdoor pollution outside, have a constant supply of clean,
fresh air, never feel stuffy nor damp and actively break-down impurities in indoor air
Products and solutions for INDOOR AIR COMFORT
Saint-Gobain offers several product categories that have a direct impact on INDOOR AIR QUALITY:
- Products with the lowest emissivity possible for the building envelope in insulation, dry lining, facade, wall or floor covering, membranes and high performance windows and doors providing superior airtightness
- Products contributing to the performance of ventilation systems such as climaver complete self-supporting ventilation ducts system and technical insulation
- Products to purify indoor air by scavenging certain (VOCs) Volatile Organic Compounds such as formaldehyde
- Low-dust screeds and adhesives improving user-comfort during installation
EXAMINE THE EVIDENCE OF INDOOR AIR QUALITY
In healthy offices, we have seen improvements in productivity with better air quality, and we can directly relate these productivity gains to an improvement of the bottom line of the builder, owner, and occupier of that office.Source: http://betterplacesforpeople.org/index.php/blog/healthy-retail-places-are-a-quick-win-for-retailers/
In the U.S. alone the savings and productivity gains from improved indoor environments have been estimated at $25 to $150 billion per yearSource: Fisk, W.J. and Rosenfeld, A.H., 1997. Estimates of Improved Productivity and Health from Better Indoor Environments. Indoor Air, 7(3), pp.158-172.
Air tightness affects the entire building envelope and plays a major role in successfully managing heat, moisture and soundSource: http://www.certainteed.com/building-insulation/air-tightness/
Up to 15 % performance reduction was observed for 3 tasks assessing children's attention and vigilance when ventilation rate was low (1 L/s.person vs 8 L/s.person)Ref: Bako-Biro et al., 2012, Building & Environment 48:215-223
“The number of non-decent homes in England continued to decline. In 2013, 4.8 million dwellings (21%) failed to meet the decent home standard, a reduction of 2.9 million homes since 2006, when around a third (35%) of homes failed to meet the decent home standard. Damp problems were more likely to be found in private rented dwellings than social rented or owner occupied dwellings.Source: The English Housing Survey, Report 2013-14. (The English housing survey is a continuous national survey commissioned by the Department for Communities and Local Government.)
“New research tapping into the public’s energy saving attitudes and behaviours has been revealed by the Energy Saving Trust in the first of a series of public opinion trackers known as the UK Pulse. The findings from the Ipsos MORI survey of over 2,000 UK respondents show nearly half of householders, 44%, claim to live in homes with draught problems, 37% in homes with condensation problems and 28% in homes with mold. All three issues were even higher among renters.”Source: Energy Savings Trust, 7 August 2014 (www.energysavingstrust.org.uk)
30% of people were willing to pay more for a home that had a positive effect on their health and wellbeing.
Co2 levels: sleep quality improves with lower Co2 levels in the bedroom, along with reported sleepiness and concentration the next day.Source: http://betterplacesforpeople.org/index.php/blog/building-the-business-case-for-healthy-residential-buildings/
“Seminal research in 2003 identified 15 studies linking improved ventilation with up to 11% gains in productivity as a result of dedicated delivery of fresh air to the workstation and reduced levels of pollutants.”Source: Loftness V. Hartkopf V. and Gurtekin B. (2003) ‘Linking Energy to Health and Productivity in the Built Environment: Evaluating the Cost-Benefi ts of High Performance Building and Community Design for Sustainability, Health and Productivity,’ –USGBC Green Build Conference, 2003.
“A meta-analysis in 2006 of 24 studies (including 6 office studies) found that poor air quality (and elevated temperatures) consistently lowered performance by up to 10%, on measures such as typing speed. This analysis appeared to demonstrate that the optimum ventilation rate is between 20 and 30 litres/second (l/s), with benefits tailing off from 30 up to 50l/s. This is significantly higher than minimum standards required, which are typically between 8-10l/s (although these vary considerably by country).”Source: Wargorcki P (ed), Seppänen O (ed), Andersson J, Boerstra A, Clements-Croome D, Fitzner K, Hanssen SO (2006) REHVA Guidebook: Indoor Climate and Productivity In Offices.
Doubling the outdoor air supply rate can reduce illness and the occurrence of the sick building syndrome by ~10 %.Ref: Clements-Croome, 2008, SJWEH Suppl 2008 (4):69-78
“In a 2011 lab test which mimicked an office, a variety of office-related tasks were carried out with the presence of airborne VOCs. Increasing ventilation from 5l/s to 20l/s improved performance by up to 8%.Source: Park JS and Yoon CH (2011) The effects of outdoor air supply rate on work performance during 8-h work period. Indoor Air 21:4, pp 284-2905.
In two independent studies, typing performance were shown to increase when the pollution source was removed.Ref: Wargocki et al., 2002, Indoor Air 12:74-80
“Research led by a team at the University of Exeter Medical School, found that a failure by people to ventilate their homes could lead to the development of respiratory problems. The research discovered that adults living in energy efficient social housing may have an increased risk of asthma. Modern efficiency measures are vital to prevent heat loss and reduce energy use, yet some people, particularly those living in fuel poverty, are unlikely to heat a building enough – or ventilate it sufficiently – to prevent the presence of damp and mold, factors that can contribute to asthma.”Source: Environment International (Environment International covers all disciplines engaged in the field of environmental research).
“The Environmental Audit Committee believes that air pollution is nearing a ‘public health crisis’, causing nearly as many deaths as smoking. There are an estimated 29,000 deaths annually in the UK from air pollution. Nitrogen dioxide is known to cause inflammation of the airways, reduce lung function and exacerbate asthma. Particulate matter (tiny invisible specks of mineral dust, carbon and other chemicals) are linked to heart and lung diseases, as well as cancer. Some particulate matter lodges in the lungs, while the finest particles can enter the bloodstream, risking damage elsewhere in the body. The report says that traffic is responsible for 42% of carbon monoxide, 46% of nitrogen oxides and 26% of particulate matter pollution, and that many schools that are sited near major roads should fi lter the air coming in to the buildings. The report also recommends that new schools, care homes and hospitals should be built far away from major roads because of the dangers of air pollution.”Source: Environmental Audit Committee report (www.gov.co.uk)