Indoor Air Quality — Getting it Right

As I write this the government is agonising over whether to move from the ‘Rule of Six’ plus selected regional lockdowns to a full UK-wide lockdown.

There are plenty of pundits to analyse and pontificate upon this scenario. Meanwhile, the everyday guy and his family live in trepidation that one or more of them will catch Covid-19.

Once upon a time, the experts said that the Covid-19 virus could only be transmitted by being in close proximity to an infected person or by touching a contaminated surface. It is now recognised that Covid-19 can also be airborne i.e. it can remain suspended in the air for some time to infect people by inhalation.

Whilst airborne indoors, the survival and spread of any airborne virus, especially Covid-19 will depend greatly upon the condition of the air. Thankfully, indoor air quality which is healthy for humans will speed the demise of airborne viruses and therefore diminish the spread to others. Poor-quality indoor air, detrimental to human health favours the survival of viruses and will enhance dissemination.

Getting to Grips with Indoor Air quality

We need to think on three planes:

The physical state of the air in terms of temperature and humidity

Biological contamination and pollution — e.g. viruses, bacteria, mould spores

Non-biological contamination and pollution — e.g. NO2, Ozone, PM2.5

Pollutants are always harmful to humans, whether biological (aka “pathogens”) or non-biological.

Contaminants in air are not always harmful to humans; for example, natural benign viruses and bacteria or the natural fragrance from roses.

Some people may be allergic to airborne substances such as pet dander or pollen (both biological particulates). To those people, pet dander and pollen are pollutants. To others, not allergic to either of those, they are contaminants.

In the scenario of the pandemic, the priority is the biological pollutant Covid-19 — and where might exist — whether in people’s homes, in public venues or in work-places.

Whilst measures such as social distancing are vital to break the chain, outdoors and indoors, the requirement common to all indoor areas is ensuring high indoor quality air.

Without taking into account Covid-19, poor air quality air, in its own right, is notorious for health issues, for example:

Hindering growth and lung capacity of children

Affecting the heart, lungs, brain, other vital organs,

The health of expectant mothers and the developing foetus.

It has such an impact on brain function that it reduces cognitive performance and, in the workplace, will reduce productivity. It will increase sickness absence and reduce employees’ general wellness.

Covid-19 viruses become airborne in millions of microscopic droplets exhaled in an invisible cloud or ‘aerosol’ by people as they breathe. That aerosol becomes visible on cold days as people exhale and you can ‘see their breath’.

The problem is that, indoors, these droplets can remain airborne for many minutes (even hours) or even become attached to airborne particulates PM1 and PM2.5, inhaled deep into the lungs.

Know your air!

‘You can’t manage it if you don’t monitor it.’

Knowing what pollutants exist in indoor air and their concentrations is absolutely vital. Employers need to know and record that the air supplied to employees is health and they need also to reassure their employees.

Employees have what has become a human right to breathe healthy air. Why should they endure poor quality air, risking their personal wellbeing when, with today’s technologies, there is absolutely no excuse for supplying poor air?

Technologies are now capable of revealing and proving that employee ill-health is due to long term exposure to poor air. And that leaves employers wide-open to litigation.

There are a number of very capable indoor air quality (IAQ) monitors on the UK market suitable for commercial applications. Arguably, foremost amongst these is the uHoo IAQ monitoring system.

Not only do uHoo monitors facilitate minute by minute detailed reporting across nine IAQ parameters but also integration with BMS and BAS. Data can also be presented on video display screens to inform building occupants about the air quality they are obliged to breathe.

In June this year, uHoo introduced the remarkable ‘Airborne Virus Index’ as part of uHoo’s standard data package.

A world first, the Airborne Virus Index shows people if the air around them is promoting or impeding the survival and spread of viruses. When the index alerts that air quality is favourable to viruses, the app gives advice on how to rectify it.

The index is proving to be very helpful to commercial and non-commercial organisations focused on making the workplace healthier, more inviting and reassuring to employees.

You can see more about the uHoo IAQ monitoring system at

Clean Air Technologies

After self-isolation and social distancing, the primary solution at home or at work is clean air.

Clean air at work starts with clean and well-maintained HVAC systems.

In the commercial and institutional sectors, HVAC systems have an unfortunate reputation of ‘Out of sight, out of mind’ and ‘Fit and forget’.

I have visited buildings with hundreds of employees fed with air through HVAC systems I can only describe as ‘utterly disgusting’ — filthy, broken and bypassed filters, filth-lined ducting, fan-coil units and diffusers.

In this state, an HVAC system is a repository and breeding ground for pathogens and particulates including mould spores and more — and above all, a present and real threat to the health of employees.

Two technologies stand out in the context of cleaner air in commercial settings —

Ultraviolet Germicidal Irradiation (aka UVGI) and Air Ionisation.

Sadly, the UK is about 10 years behind the USA in the integration of these technologies into HVAC systems. For example, several years ago, the US Government’s General Services Administration mandated the installation of UVGI in the HVAC systems of all new and refurbished US Government Buildings.

There is no pathogen known to man which can survive proper exposure to UVGI.

With emitters of UV-C light at 253.7nm wavelength, UVGI has one primary function — to destroy or deactivate all biological matter, both airborne and deposited within the HVAC system.

Correctly installed UVGI ensures that the air delivered into the workspace is free of pathogens. UVGI has no power of air filtration and relies entirely on the HVAC system’s filters to remove particulates.

‘Correctly installed’ is the key to ensure optimum efficacy of UVGI. There are several good suppliers in the UK but perhaps the longest standing and most informed suppliers is Mr Hillary Spicer at Apart from having a prodigious knowledge base, installs one of the world’s top UVGI systems from Steril-Aire Inc. Burbank California.

The installation of UVGI is particularly important in air handling units which recycle indoor air mixed with fresh air — usually in a ration 80:20. The ultraviolet irradiation will destroy the pathogens released into the air by people before the air is fed back into the building.

An additional benefit of UVGI is its ability to keep HVAC cooling coils clear of biofilm thus enhancing heat exchange efficiency resulting in a major reduction in associated energy consumption at fans and pumps etc.

Air Ionisation

This technology, usually installed into HVAC systems works by emitting positive and negative ions into the air supplied into the ventilated areas.

It causes the agglomeration of airborne particulates and aerosols causing them to fall to the nearest surfaces by gravity and/or electrostatic attraction.

In doing so, pathogens (harmful viruses, bacteria, mould spores etc.) are prevented from inhalation by building occupants. Many types of bacteria and viruses are irreparably damaged and rendered harmless in this process.

Air Ionisation depends on high voltage, low current electrical discharge and therefore some poor quality systems can produce ozone — a very strong lung irritant. Avoid these.

Strictly speaking, Air Ionisation is not a filtration system but has a function which cleans the air.

In the UK, there are two outstanding brands of air ionising systems both originating in the USA:

PlasmaAir — Mr Adam Taylor at Spire Building Services

AtmosAir — Mr Gary Novak, Sales Director Europe, AtmosAir

AtmosAir is the most recent entry into the UK market but brings with it a simply formidable list of successful, high-profile installations and testimonials.

New in the UK is a range of in-room air ionisers by Teqoya of France. Neat and elegant, these are free-standing or ceiling suspended and do exactly the same job as in-HVAC ionisers systems. To learn more about Teqoya products in the UK, contact the author of this article.

Graham Mills is MD of AirProfiling Ltd.

+44 (0)1636 555 007

This article first appeared in the October Air Quality News magazine, which you can read here. 


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Max Jones
Max Jones
3 years ago

Thanks for explaining that air ionization helps to prevent pathogens from being inhaled. My children have weak lungs, and I am concerned about the air quality in my home. I’ll look for a professional that can help me with getting air ionization for my home so my kids can be safe from pathogens.

Rachelle Waterson
Rachelle Waterson
3 years ago

Great read! I agree that Plasma Air purification system is really one of the best in the market as based on what I read here it is durable and of good quality as it could last around 12-15 years with only little to no maintenance at all. However, what’s more important is that it is safe as it does not create any harmful byproducts after the air bipolar ionization process. I’m glad to know that the brand of air purification system I have installed here in my home is also recognized as a good brand even in the UK.

Rebecca Gardner
Rebecca Gardner
3 years ago

I was suprised when you said that poor air quality can affect the lung capacity of children. My sister mentioned she wants to make sure her home is completely safe since she’s preparing to adopt a child this summer. I’ll let her know she should schedule a duct cleaning to make sure the air quality in her home is acceptable.

Shaylee Packer
Shaylee Packer
3 years ago

It was mentioned that clean air quality indoors begins with a well maintained HVAC system. We recently moved into a new home, and the air seems stuffy. I wonder if the air ducts need to be cleaned.

Vincent Valles
Vincent Valles
3 years ago

Install a permanent ionization air purification system, onto the walls of your home or office for less than 10 cents per sq. Ft. No electricity, filters or servicing required. Ionic paint additive

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