COVID 19 and FLU – getting building ready for our new way of working

We must all prepare to take air quality more seriously as much has been written about the ‘new normal’. What does that look like now we know the Covid virus and Flu spread by direct contact and via airborne droplets and from touching contaminated surfaces? Hands, face, space does not yet include government guidance on what to do with air in our buildings.

Air quality is Envirotec’s business so we take it very seriously. Our products and 51 years HVAC history in any sector you care to mention – including pharmaceutical and healthcare – demonstrate that Envirotec delivers innovative critical equipment to high demanding specifications.

Part of Envirotec’s role is to keep you informed of the changes applicable to the HVAC industry. We believe we can help deliver a healthy and productive environment for people to work, study, relax and enjoy.

We did that in 2003 in answer to the SARS outbreak and again in 2009 by extending our research further with the Swine flu pandemic and by launching destratification air curtains that take virus free air from high in buildings to deliver uncontaminated air to entrances. Please continue reading for guidance or call Tim now on 07557 747 400 if you would like to discuss this topic or if you want to understand how we can help with your ventilation requirements.

The Return to Work – getting our buildings ready

Businesses in the UK are encouraging employees to work remotely where possible to limit close working with colleagues and reduce social interaction by not commuting to offices. Questions abound over what will happen on their return to offices and how changes will affect them.

Numerous reports in the media show desks taped off and floors with warning tape to show safe distancing measurements. Hand sanitiser stations, occupancy limits in lifts and posters reminding people of the general safety measures are the order of the day. These essential and welcome safety measures are helpful reminders.

What is currently missing is guidance on the IAQ / IEQ – the indoor air / environment quality.

Evidence points to poor ventilation being responsible for increases in the rate of airborne transmissions.

Therefore, understanding what changes to make to the building’s ventilation system and how it should be used is essential.

Industry guidance

The importance of wellbeing and providing a healthy and “safe” environment for people within buildings has led to guides being published by industry bodies outlining some of the key elements when preparing for the return to work.

CIBSE has set out a number of recommendations for the building’s ventilation system including;

  ⦁ Understand the ventilation system in the building. Is it, natural ventilation (opening windows), is it all mechanical or a combination of both? If mechanical, what are the key components – mixing boxes, thermal wheels, plate heat exchangers?
⦁ Increasing the ventilation rate – may require adjustments to CO2 set points within rooms if sensors are installed. CO2 concentration provides a general indication as to indoor air quality. If the set point is reduced, the ventilation rate increases and dilutes the CO2 exhaled in the space. Our boss likes 400 ppm and CIBSE recommends reducing the set point to 400 ppm (parts per million)
⦁ Avoid recirculation/transfer of air between rooms
⦁ Thermal wheels – turn off to avoid cross contamination of exhaust and supply air
⦁ Mixing boxes – do not use as a method of heat recovery
⦁ Plate heat exchangers – use, as only energy is transferred
⦁ Increased duct cleaning -, if the guidance above is followed

Following a paper published in March 2020 by the W.H.O. The REHVA (Federation of European Heating, Ventilation and Air-Conditioning Associations) produced recommendations for building owners for HVAC systems. They advise

⦁ Service and maintain the HVAC systems in line with manufacturers recommendations. Filters don’t require changing sooner than usual but take special care when replacing filters – switch unit off and place used filters in a sealed bag for removal. Maintenance personnel should wear protective equipment including gloves and respiratory protection.
⦁ Avoid energy saving, demand-controlled ventilation settings
⦁ Extend the ventilation system operating times, starting on nominal speed for 2 hours before building usage and at a lower speed for 2 hours after usage
⦁ At night and during weekends, keep the ventilation system running at a lower speed
⦁ Increase the number of air change rates per hour over and above the minimum levels stipulated in Building Regulations  ⦁ Switch air handling units with recirculation to 100% outdoor air

The HSE (Health & Safety Executive) have provided some general advice on ventilation systems in buildings including;

⦁ Employers must, by law, ensure an adequate supply of fresh air in the workplace and this has not changed.
⦁ Good ventilation can help reduce the risk of spreading coronavirus, focus on improving general ventilation, preferably through fresh air or mechanical systems.
⦁ Where possible, consider ways to maintain and increase the supply of fresh air, for example, by opening windows and doors (unless fire doors).
⦁ Also consider….improving the circulation of outside air…..provide good ventilation…
⦁ The risk of transmission…..is extremely low providing there is good ventilation……preferably provided by fresh air

Temperature and Humidity

Discussions and research (ASHREA and REHVA) on the effect of temperature and humidity suggest that maintaining a relative humidity level of between 40 – 60% in buildings will help reduce the transmission of airborne infectious organisms. At this range the belief is that infectious aerosols will quickly settle out of the air and can be wiped from surfaces. People also have greater resistance against absorbing infectious microbes when the RH level is between 40 – 60%.

Next steps

We are still in the early stages of the Convid pandemic and await the annual flu season. As research and analysis continues, so too will the advice and guidance adapt and change on how to manage our buildings.
The REHVA and CIBSE guidelines will be updating to cover considerations for autumn and winter operation.

In the meantime, we have a product portfolio that includes devices that can improve and protect air quality; it makes sense to make a modest investment so please do get in touch with Tim on 07557 747 400.

Thank you for reading.