Recirculating Air To Save Energy…During A Health Crisis?
Recirculating the air in commercial buildings in order to save energy and reduce companies carbon footprint has been common practice for decades, with the argument being that cooling and heating the air – particularly in large buildings – is expensive, so why not recirculate it, rather than let it go to waste? A fine idea in principle, if you choose to simply ignore the fact that doing so also means recirculating viruses and bacteria, allowing things like coughs, colds and autumnal flu to spread like wildfire through schools and offices.
The advent of COVID-19 meant that the practice of recirculating air was no longer advisable, and facilities managers were told to let in 100% fresh air instead. Problem solved. At least it was, until the energy crisis came hot on the heels of the pandemic, leaving us with a bit of a dilemma. With energy-saving now being even higher on the agenda for a lot of workplaces and other commercial properties such as schools and hospitals, the question of whether or not to relax the guidance about supplying only fresh air in buildings is now being asked. But, with COVID still circulating and infections set to increase during the autumn and winter months, what is the solution?
Ideally, something that saves on HVAC (heating, ventilation and air conditioning) energy AND makes indoor environments safe from COVID and other winter viruses. The answer is UVGI technology – one product that solves both problems. Our UVGI arrays installed in the main AHUs (air handling units) can save around 15% to 20% of HVAC energy, all while intercepting and inactivating any and all viruses circulating within the ventilation system.
But what exactly is this technology, and how does it work?
UVGI (Ultraviolet Germicidal Irradiation) uses UV energy to kill viruses, bacteria and fungal organisms by producing UV-C energy, which has shorter wavelengths than UV-A and UV-B rays and is less of a risk to human health. The most effective way to harness these rays is to install this technology in the upper parts of a room, so that airborne pathogens can be killed in the room where they are released, without people in the room being exposed directly to the UV rays. As the air passes through the ‘kill zone’ from the HVAC system or open windows, airborne pathogens are exposed to the UV energy and disinfected, remaining in the air, but no longer posing a threat.
This is particularly beneficial in high-risk or crowded indoor settings such as office buildings, school and hospitals and, during a pandemic, anywhere that people have to remove masks in order to eat or drink, as well as in areas where maintaining social distancing is difficult. This technology isn’t new, in fact upper-room UVGI has been used for over 70 years, with most of the research focusing on preventing the spread of tuberculosis. Today, the primary concern is COVID-19, which is very similar to other coronaviruses such as SARS with regards to the UV dose that is needed to make it inactive. Influenza viruses are even more susceptible to UV energy, and so UVGI systems are useful in the fight against seasonal flu – the yearly bugbear of many an office space. In fact, UVGI is even more effective at combating the influenza virus than it is the bacteria that causes TB, and so installing this type of system is essential in saving not only energy costs, but labour costs as well.
Aside from reducing the risk of COVID-19 and other infections, having good indoor air quality has huge benefits that include higher levels of employee and student productivity, people taking less sick days, better cognitive function, and better respiratory health. So, has the years of recirculating air in commercial buildings been nothing but a terrible mistake?
Not when you consider that we are in the middle of a climate crisis, and have been for quite some time. The energy used in large buildings creates a sizeable carbon footprint, and conditioning the air plays a huge part in that – so it’s no wonder that finding energy-efficient solutions such as recirculating cooled or heated air is incredibly important. However, it has been argued for years that methods used to recirculate the air in office, school and the like is unhygienic – even before COVID – and anyone who has ever worked in a building with recirculated air and has seen (or experienced!) what happens in the wake of one person in the office getting the flu or a cold, can attest to that.
E-Co and Steril-Aire are the leaders in UVC HVAC solutions in the UK. Our UVGI systems pay for themselves within 12 to 24 months in energy savings alone, helping you to save money and reduce your carbon footprint, as well as killing 99% of bacteria, viruses and mould – killing two birds with one stone, and helping to combat both the energy emergency, and the health crisis.
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