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Getting to grips with IAQ facts

Mark Grayston, head of product marketing at Mitsubishi Electric discusses the importance of understanding, monitoring and improving indoor air quality (IAQ) and calls for a recognised set of standards to regulate it

Mark Grayston, head of product marketing at Mitsubishi Electric

The link between the air we breathe and our health and wellbeing is already well documented and understood. There are ongoing calls for a reduction in the amount of traffic around schools as it can be harmful for children, more cities are developing low-emission zones to reduce air pollution, and an increasing number of people are investing in electric vehicles. 

In contrast, the quality of air within buildings has often been overlooked, and given far less scrutiny. The concept of Sick Building Syndrome, where people suffer from illnesses or chronic conditions as a result of inadequate cleaning, poor ventilation or building materials that are harmful if breathed in, is not new. However, not enough has been done to date to ensure that the air in the spaces we use most often - offices, homes, shops and restaurants - is up to a high enough standard, and this can have a serious impact on our health. Considering we spend the vast amount of our time indoors – even more so during ongoing lockdowns this year – it is vital that we take a closer look at our IAQ going forwards. 

Indoor air 

We spend around 92% of our lives indoors. As a result, most of the air we breathe is from within our homes and offices. If this air is of poor quality, filled with harmful chemicals or pollutants, it can pose serious health risks. With the level of pollutants in office buildings reaching up to 2-5 times higher indoors than outdoors, we must take IAQ seriously. 

This situation is worsening due to growing urbanisation, as the UK’s cities continue to expand as hubs for employment and living. This results in more densely built areas and higher levels of emissions from the transport needed to propel these growing populations around.

The need to grow and maintain these cities has also led to us being surrounded by harmful chemicals. Volatile Organic Compounds (VOCs) are everywhere; from the fabric of our offices – due to the materials used to build the actual space – to the furniture in our homes and the clothes we wear. This is in addition to the cleaning products used to sanitise workstations, restaurants or shops at the end of the day.  

Looking at this alongside the host of new building regulations that require greater air tightness in buildings, it is clear that there is a compelling case for improving the quality of air in the spaces we occupy.


In short, the key to maintaining good IAQ is removing polluted air from a building and replacing it with fresh, filtered air. It sounds like a simple process, but without the right kind of guidance, this is often overlooked. 

Mechanical ventilation with heat recovery (MVHR) can transfer an average of 80% of the energy, or more, from outgoing stale air to heat incoming fresh air, which means less energy is required to heat the building compared to non-heat recovering ventilation systems. When paired with a BMS, this can also be used to regulate air flow throughout an entire building. 

Mechanical ventilation also delivers a slow but constant movement of air throughout the building, unlike natural ventilation, which delivers uncontrolled air supply.

Any air flow management should also be looked at alongside a system of sensors, designed to pick up on fluctuating in-building environmental conditions and thereby improve air quality. These are especially useful as a built environment can change, and conditions and requirements within buildings can evolve. 


There are already measures in place to calculate air quality outdoors around the world, such as the US Air Quality Index which ranks air quality from Good to Hazardous and is regulated by the Clean Air Act – but these measures focus on external air quality, and there is currently limited guidance around the impact of indoor air quality specifically. 

In addition to providing builders, installers and the public with a better understanding of why IAQ is so important and how to improve it, there are now calls for an official index to monitor it. In the UK, IAQUK has developed a IAQ Rating Index which ranks IAQ from Excellent to Inadequate and is calling for the introduction of a standard, but it is not currently a recognised index. With a set standard to assess and rank the quality of air, offices, hotels, restaurants and other spaces, it will be possible to assure occupants that they are in a safe environment, and empower them to make informed choices about the air they choose to breathe. 


3 March 2021


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