Removing air pollution without adding noise pollution

Removing indoor air pollution has proven benefits. Not just the obvious advantages of protecting your health from bacteria, viruses and allergens, while minimising sick building syndrome. Clean air is also proven to boost your productivity and cognitive functions. 

So what’s the downside? Do you have to compromise by putting up with noise pollution in order to remove air pollution?

Definitely not. But you could be forgiven for thinking so.

First, you’ve got to cut through lots of noise in the market. Leading experts including the WHO, SAGE, CDC, ASHRAE – and even NASA – recommend two technologies: HEPA and UVC. The clamour around other technologies is that they lack proof of efficacy and can cause harmful side effects, such as respiratory problems or skin irritation. 

Once you’ve chosen HEPA and UVC to capture and kill the pathogens in the air, Rensair is the obvious choice. But is there a price to pay in terms of the noise level? 

Most devices that use HEPA filtration deploy axial fans, which are designed to be quiet. However, there’s no point having a quiet fan if it fails to circulate the air and only cleans the space around the machine itself rather than the entire room.        

That’s why Rensair uses a robust centrifugal fan, which creates much higher pressure than the axial fans commonly used in other air purifiers.The effect of pushing air down into the chamber creates high static pressure, forcing high volumes of air out through the dense H13 HEPA filter, achieving effective air circulation and ensuring clean air throughout the entire room. In theory, it should be louder than its axial competitors, but it’s not.

Rensair’s patented, enclosed design ensures that it is quietly effective. The unit has three airflow settings: low, medium and high. To measure noise levels we use the dBA scale, which reflects what the human ear actually hears. On the low setting, it produces an even white noise at  45dBA, equivalent to the recommended white noise level limit for an infant sleep machine. On a Sound Pressure Level (SPL) metre, it sits between ‘quiet whisper’ and ’quiet home’. Within an office environment, this not only falls within regulatory guidelines, it carries additional benefits.

Nowadays, most offices are open plan. Many companies actually pay for sound masking machines that deliberately add unobtrusive background noise to manipulate the acoustics in the room and block sound travel. The manufactured noise is similar to airflow, so the Rensair unit is effectively doing two jobs.   

The purpose of sound masking is to render nearby conversations less intelligible to others. This reduces distractions and increases privacy. Research shows that the addition of white noise can increase speech privacy from 35% to 90%. Without conversational distractions, office productivity goes up. Research shows that workers in offices without sound masking can lose as much as 21.5 minutes per day of their productivity and that there is a 10% improvement in people’s ability to recollect a series of numbers and words after the addition of sound masking.

On a medium setting, the Rensair unit operates at 52dBA, equivalent to a ‘quiet home’ on the SPL metre. On the high setting, it operates at 59dBA, on a par with a ‘quiet street’ on the SPL metre, which is fine for a lively place like a restaurant or pub with some background music present. Many customers stick to the auto setting, which automatically adjusts according to the concentration of particulate matter in the room, increasing airflow when needed and reverting to low when conditions are back to normal. 

Indoor Air Quality is a growing problem and is typically 3.5 times worse than outdoor air pollution. Rensair is revolutionising the air purification sector, providing hospital-grade clean air that is ideal for office environments. At a third of the price of the nearest hospital-grade equivalent, it’s not just its 45dBA quiet efficiency that is music to our customers’ ears.

And, in case you were wondering, we throw the sound masking in for free.

By Christian Hendriksen, Co-founder & CEO, Rensair