As we all get to grips with the latest lockdown, businesses have to explore new ways of working in a COVID-19 secure manner. So how can you ensure that your workplace, be it a factory, warehouse or office, is properly prepared to reduce the risk of the spread of Coronavirus amongst your workforce.
In our previous blog we explored some of the latest scientific theory surrounding the potential for the airborne spread of COVID-19 through building ventilation. For building managers it is very important to be fully aware of every step they can take to limit the transmission of contaminants in the workplace.
In this blog we aim to suggest some practical steps you can take to make your building COVID-19 resilient – it’s important to remember that where viruses are concerned the realistic goal is to make your building ‘safer’ rather than ‘safe’. It’s simply not possible to eradicate completely the potential of a COVID-19 outbreak in a typical workplace as there are other factors, beyond your control, which come into play.
Figure 1 Whilst ventilation is a very important control measure in preventing the virus spreading, simply providing ventilation is not sufficient. Having a well designed system in place will have a greater impact on preventing the spread of the virus. Image source: Morawska et al.; Clinical Infectious Diseases 2020 (CC BY NC ND 4.0)
The importance of fresh air in the workplace
Even before the Coronavirus outbreak, the benefits for both employees and employers of having a steady supply of fresh air in to the workplace has been demonstrated repeatedly by studies. From the sick building syndrome of the 1980s to the latest Coronavirus modelling there is evidence that fresh air is an essential ingredient to a healthy and safe working environment. A well designed ventilation system can reduce the likelihood of high blood pressure; aid with your digestion; strengthen your immune system; improve your mood and sharpen your mind. Whereas areas with poor ventilation become a breeding ground for respiratory viruses and bacteria. As shown in this video, the virus will spread quickly over one hour without sufficient ventilation in place.
Employers have always been required by law to ensure that there is an adequate flow of fresh air coming in to the building. In the UK, Approved Document F and various CIBSE guides are the benchmark to achieve acceptable levels of ventilation, and go beyond this to propose ‘Best Practice’. However, in the times of COVID-19, the importance of fresh air inside a building has become even more relevant for building managers.
How your ventilation system can reduce the spread of COVID-19
As someone responsible for the health and wellbeing of people working in your building you can play your part in reducing the spread of the virus by utilising your ventilation system to help keep your employees safer.
As you might imagine in such volatile times the scientific community are working hard to understand the key routes to infection and the effectiveness of the various preventative measures available. A recent article looked at a range of scenarios and known Coronavirus events around the world and modelled how factors such as exposure time, face coverings, distancing, and ventilation strategies effected the number of people infected with the virus if one contagious person was present.
One message was clear; in all scenarios an effective ventilation system was a critical element to reduce the spread of the virus.
Closer to home the government and the Chartered Institute of Building Services Engineers have released guidance pertaining to the general safekeeping of buildings including factories and warehouses from COVID-19.
Given the speed of change with the pandemic it is unsurprising that guidance on ventilation is still developing. By keeping in contact with your ventilation specialist who are up to date with the latest guidance you can ensure your factory or warehouse is well equipped to reduce the transmission of Coronavirus. The latest guidance states that as long as there is good ventilation then the risk of transmission through the use of celling and desk fans is extremely low. Likewise, the risk of air conditioning units spreading Coronavirus through the workplace is believed to be extremely low, provided there is a good level of general ventilation.
We recommend that you fully understand the ventilation system you have installed and the operation modes available to you. Even if you are confident your ventilation system is working as it should there are a number of recommended steps you can take to help in the fight against COVID-19;
- You can run your ventilation at higher volume flow rates. This will aid air movement and dilute any contaminants in the building. (This may require changes to your control set points or the configuration of your system – so contact your specialist.)
- Avoid the recirculation or transfer of air from one room to another as this could lead to an increase in viral load or spreading the virus to unaffected areas both leading to a potential increase in cases.
- However, you should continue to do this if this is the only way of providing adequately high ventilation to all occupied rooms - Recirculation of air within a single room where this is complemented by an outdoor air supply is acceptable.
- A recent BBC article has advised that you should find out what the fresh air ratio is in your building, and whether your ventilation system needs to increase its supply of fresh air. Also, you should ensure that the filters in your ventilation system are checked regularly and cleaned.
- It has been recommended that buildings with mechanical ventilation systems should start using extended operation times. In demand controlled systems for example, the CO2 set points should be altered to 400ppm to increase the delivery of outside air.
- Introduce a ‘purging cycle’ to spaces before the start of each period of occupancy to help reduce the level of contamination.
- If applicable to your ventilation system, enthalpy (thermal) wheels should be turned off, but the pressure difference will need to be maintained between supply and extract to minimise any leakage flow from the extract to supply side.
- If applicable to your system, it is recommended that any ventilation or air conditioning system that normally runs with a recirculation mode should now be set up to run on full outside air.
- You should aim to dilute any internal air, ideally by using a displacement ventilation strategy. This should reduce any risk of potential airborne viral transmission by reducing exposure time to any airborne viral aerosols.
- Increasing ventilation rate will also reduce the potential for these aerosols to settle on any surfaces. Although recent studies suggest that transmission via surfaces isn’t as likely as first thought action to limit surface contamination reduces the underlying chance of infection and is therefore beneficial to reducing the spread of COVID-19.
- By keeping your ventilation system on for longer, even when people are absent to reduce viral load in any area (by dilution).
- It is not recommended for any buildings to switch ventilation systems off, even those that have been temporarily vacated, but instead to operate them continuously at reduced speeds.
- The REVHA guidance supports the idea that your ventilation system should be purged at the beginning and at end of the day.
- Furthermore, your toilet ventilation should be running continuously, 24 hours a day, to reduce any contaminants entering the air stream.
In our next blog we will look at how winter may affect your COVID-19 security steps and in particular how trying to maintain a high fresh air ventilation rate may be a challenge as outside temperatures fall.
Colt’s range of ventilation products can help your building, be it factory or warehouse, to reduce the spread of COVID-19. If you wish to discuss any aspect of your ventilation system contact Colt for a no obligation consultation today.
If your building is too hot or too cold, if your process gives off fume or moisture, if your product requires specific conditions during its manufacture or storage, or if noise is a concern, then we may be able to help you.
We can survey your building using a range of techniques and equipment to identify your problem. Once established, we can then recommend a solution based on proven design work.
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Paul Langford is an Engineering Director with experience in product development, manufacturing and testing for HVAC, solar shading, louvre systems and smoke control applications.
