Prioritising indoor environmental quality

[edit] Introduction

We spend over 80% of our time indoors. Recent publications about the poor air quality (AQ) in our towns and cities, coupled with investigations on the link between AQ and coronavirus transmission, as well as intensifying climate change lobbying are making people increasingly aware of the importance of good air quality.

[edit] Consequences of poor indoor air quality

Contaminant sources from building materials or human behaviour indoors can make the indoor air eight to 10 times more polluted than the exterior air, according to the World Health Organisation (WHO).

More and more studies are beginning to report the outcome of environments where wellbeing is considered. Many point to an increase in employers’ productivity and the reduction in sick leave, bringing with them subsequent economic benefits.

Despite this, some employers and building owners tend to be reactive rather than proactive and neglecting the maintenance of the ventilation systems.

[edit] Measuring impact

Indoor air quality (IAQ) at work is measured when it is obvious staff may be at risk, based on specific HSE procedures for special contaminants or industries. But in an office environment, measurements tend to be carried out when there are scheme points to be achieved or when there are sick building syndrome related complaints.

Some IAQ related problems could be avoided if it was considered at the design stage. This might include reviewing the following:

• The location of supply and extract grilles in the building.
• The assumption that outside air is fresh.
• The selection of filtration.
• The selection of building and furniture materials.
• The design for effective ventilation.

The next steps would be proper commissioning and maintenance of the ventilation systems. Duct cleaning and filter maintenance should reduce the levels of external contaminants (such as PM2.5 and PM10) being brought into the space.

Checking and limiting condensation and using UV lights should stop bacteria from growing and spreading in the ventilation system. Controlling humidity levels and ensuring the right ventilation in places, such as kitchens and bathrooms, should also stop mould from growing.

Well designed, effective ventilation should remove most pollutants and odours in a common office environment. Isolating the source of contaminants should also be considered: e.g. some printers release ozone, which is a contaminant, so having the printer in a ventilated room or open area, rather than in a closed room, should help.

IAQ does not consist only of measuring the temperature, humidity and carbon dioxide (CO2) in a space, but measuring for a long list of contaminants can be expensive, so an informed approach must be found. The level of CO2 in an occupied space is a good indicator of the general IAQ and overall ventilation effectiveness, but it is only meaningful if the space is occupied.

[edit] Other causes of poor IAQ

Human behaviours (e.g. the use of perfumes and cleaning products), office furniture and building materials are sometimes a source of Volatile Organic Compounds (VOC). VOCs are many, and their effect on health can vary, depending on the contaminant (from causing respiratory system irritation to cancer). Measuring for Total VOCs (TVOC) as a whole and identifying the VOCs with the largest concentrations can give an indication of where the problem is - it is not an expensive test.

Ensuring that the ventilation system is on (and working properly) can dilute the concentration of these contaminants, and proper selection of building materials can limit their release into the building. For instance, if the office is being repainted or refurbished, selecting materials that do not have a high VOC emission rate and flushing the building should reduce the VOC concentration levels.

The location of the building can indicate what contaminants to look for. If it is next to a busy road, measuring for nitrous oxides (NO, NO2) and particulates (PM2.5 and PM10) should be considered. If the building is on a Radon (Rn) area, checking Rn levels in the building and investigating ventilation solutions should be a priority, as exposure to Rn, which is naturally released from the ground, can cause lung cancer.

[edit] Covering the full spectrum

Indoor environmental quality (IEQ) looks beyond IAQ and considers the wellbeing of people in a holistic way. IEQ looks not only at air quality, but also includes lighting, acoustic and thermal comfort, and some wellbeing standards. It also takes nourishment, water quality, ergonomics, electromagnetic frequency levels and building aesthetics into consideration.

In summary, approximately 90% of the associated costs of a building are staff related. IEQ not only affects people’s health and productivity, but it also has an impact on the building management. It can make one space a desirable space to sell or rent, while it can make another require extensive and costly investigations to rectify. Therefore, providing good IEQ at work should be a priority for employers.

This article was originally published as 'Indoor Environmental Quality as a priority concern in buildings' by BSRIA in May 2020. It was written by Dr Blanca Beato-Arribas, Microclimate Team Leader, BSRIA Test.

--BSRIA

[edit] Related articles on Designing Buildings Wiki

• Air quality.
• At a glance - Indoor air quality.
• Bringing a breath of fresh air to the design of indoor environments.
• BS ISO 17772 - Indoor environmental quality.
• BSRIA articles on Designing Buildings Wiki.
• BSRIA responds to UK Air Pollution Report.
• Fresh air.
• Health effects of indoor air quality on children and young people.
• Indoor air quality.
• Indoor environmental quality.