As the UK begins to ease lockdown restrictions and businesses return to work it is important to consider the role of indoor ventilation in creating a safe and healthy work environment.
It is understood that the Coronavirus is spread when very small particles, called aerosols, are released by an infected person when they cough, sneeze, talk or even just breathe. As businesses plan how to safely return to work, it is crucial to know how to best minimise the risk of the virus spreading in your building.
It is common knowledge that building ventilation is crucial when creating a healthy environment. This is because it ensures that a steady stream of outside air is brought into the building whilst air that includes body odours and exhaled breath is expelled. Ventilation is also important as it dilutes airborne pathogens – in turn reducing the chance of spreading disease.
Advice from the Chartered Institution of Building Services Engineers recommends increasing the rate of supply of outside air wherever practical to minimise the risk of airborne transmission of SARS-CoV2.
Their advice suggests increasing the air supply to include as much outside air as is reasonably possible. Further to this, the recirculation and transfer of air from one room to another must be avoided.
Rooms, where it is impossible to supply outside air, should be given prohibiting access – especially when occupants are likely to spend a considerable amount of time in these rooms.
How to safely reopen your building
Prior to reopening your building it is necessary to establish what ventilation system currently exists and if and how the ventilation rate can be increased. This may vary according to the room. Read through the following recommendations on how to improve ventilation depending on whether or not your building uses natural or mechanical ventilation.
Natural ventilation
To boost the rate of outside air supply the obvious solution is to open external doors and windows for as long as possible. If a room only has windows/ vents on one side, it is recommended that a local recirculation unit is used, such as a fan, to promote circulation in stagnant areas.
Cross ventilation is encouraged as greater airflow can be achieved when windows/vents can be opened on different sides of a room – increasing the outdoor airflow and consequently the removal of airborne pathogens. However, cross ventilation where air travels from one occupied room to another should be avoided.
Automated windows and vents must be adjusted to promote more active window opening and if this is not possible the CO2 setpoint should be adjusted to 400ppm.
Windows in toilet blocks should be left open as long as reasonably possible but it is important that toilet doors are kept closed to avoid pollutants from entering the rest of the building.
Mechanical ventilation
Buildings that use mechanical ventilation systems must extend their operation times. Changing the clock for ventilation to start at least two hours before the building is used, and ending the ventilation only two hours after the building has closed, will assist in reducing the amount of recirculated air being spread.
In demand-controlled ventilation systems, it is recommended that the CO2 setpoint is set to a lower, 400 ppm value, in order to maintain the operation at nominal speed. It is also required that ventilation should be kept on 24 hours a day, seven days a week and relative humidity should be kept above 40% wherever possible.
Additionally, to avoid recirculation and prevent the risk of transmission of airborne viral particles in the building, the advice is to close the recirculation dampers (via the Building Management System or manually).
Although this advice may impact the building cooling or heating capacity, it must be accepted because it is more important to protect public health than to guarantee thermal comfort. This may require businesses to relax their dress codes while we live with this pandemic.
Voltix Services is up to date with the latest recommendations from the government and the Health and Safety Executive (HSE) and we are accredited to carry out a range of testing, maintenance and compliance services, in order to assist your facility in maintaining the highest levels of health and safety during the pandemic.
Enquire now to find out how Voltix Services can assist with expert advice and efficient service while you prepare your building for a safe return to work.