Why indoor air quality is so important


23 February 2022

The common narrative for being healthy is centred around carrying out regular exercise and maintaining a well-balanced diet. However, an aspect overlooked far too often is indoor air quality.

The fact that we spend up to 90% of our time living, working, learning and socialising within inside spaces, it is surprising that this issue wasn’t raised more vocally until Covid changed all our frames of reference about the importance of indoor air quality. 

We spoke with Martin Passingham, department manager product and training at Daikin, to discuss what affects indoor air quality, why it is so important, and how to deliver it successfully.

Martin, could you explain what affects indoor air quality?

Numerous interior and exterior elements can affect indoor air quality. Exterior factors include the proximity of a building to busy roads and building sites, the closer a building is situated to these will result in poorer indoor air quality. Indoor sources include Volatile Organic Compounds (VOCs), which originate from floor and wall coverings and furniture, dust, damp and mould, and let’s not forget the occupants themselves, who release CO₂ as they breathe and are fantastic at spreading colds and viruses.  

Of course, without systems put in place to combat these sources, a building manager will struggle to achieve a good level of indoor air quality.

Why is it important that indoor air quality should be prioritised?

We spend the majority of our lives indoors, so it is critical that we ensure occupants have access to a healthy and clean indoor environment by prioritising removing pollutants, allergens, odours and water vapour from these spaces. 
Air pollution can cause a number of health issues, some of which can be severe. More mild health impacts include irritation to the eyes and respiratory systems, but prolonged exposure to poor air quality can result in developing chronic cardiovascular and respiratory diseases. To put it into perspective, Public Health England has estimated that air pollution is responsible for between 28,000 and 36,000 deaths a year, costing the healthcare sector £20bn annually. 

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Aside from the many physical health related consequences of poor indoor air quality, growing evidence suggests it can have a significantly negative impact on an individual’s mental health and general wellbeing, with research arguing that indoor air quality is a factor in conditions such as depression and bipolar disorder, as well as having a detrimental effect on children’s learning ability and productivity levels. Whilst poor indoor air quality has an adverse effect on physical and mental health, it is important to note that good indoor air quality results in quite the opposite, boosting productivity and improving general health and wellbeing.

How can good indoor air quality be delivered?

Most people may think that opening a window could serve as a very obvious and simple fix to the issue, however it could prove to do more harm than good if it allows harmful pollutants from the outside to enter interior spaces. Instead, improving ventilation by installing an efficient HVAC system is the most effective means in which to achieve good indoor air quality. 

Ventilation systems remove stale indoor air and replace it with ‘fresh’ outdoor air, helping to extract water vapour, airborne pollutants and odours, as well as assisting with humidity control. As such, utilising an effective ventilation system is the best approach to ensure a well-balanced internal environment. However, for a ventilation system to succeed at improving indoor air quality, system design is critical, and a number of key considerations must be taken. 
Before installing a ventilation system, it is important to first refer to the relevant building regulations. In the UK, ventilation design is controlled by the Building Regulations Approved Document Part F, which sets out the criteria for both homes and ‘non-domestic’ buildings – primarily offices. Building ventilation also has to comply with a number of other British Standards, covering energy performance, filters, sound and maintenance. Thankfully there is a variety of guidance, published by industry bodies, available regarding interior installation regulations. The CIBSE Industry TM 61-64 guides are of particular note, covering a number of essential topics including operational performance of buildings, occupant satisfaction, emissions sources and mitigation measures.

As well as the interior placement and design of ventilation units, exterior considerations such as the placement of intakes and exhaust outlets must be made. Ventilation intakes must be placed as far away from outside pollutants as possible. If placed incorrectly, the ventilation could have a detrimental impact on indoor air quality. Again, there is an abundance of guidance available to ensure that this is done correctly. 

How do you choose the correct HVAC system?

There are several elements to evaluate when selecting a HVAC system, to ensure that it is fit for purpose. The first thing to consider is the type of space. Incorporating ventilation in a domestic setting is, of course, very different than an installation in a commercial setting. In a one-bedroom property, the required ventilation rate is 13l/s, whereas in an office environment, this is generally 10l/s per occupant. As such, avoiding over and under specification is key to maximising performance and minimising operational costs. At Daikin, we have specialists on hand who will help to make sure that the right system is specified. 

Another key consideration, especially for commercial buildings, is a HVAC system’s environmental impact. There is now a focus on reducing running costs and energy consumption in modern building design, combined with the targets set by BREEAM and LEED assessments, achieving a high level of energy efficiency is becoming increasingly important. Through careful design and consideration during the initial stages, however, it is possible to achieve both excellent indoor air quality and energy efficiency.