As we get closer to larger and more complex buildings and even shared office space coming back into use we need to think more widely on the issues of risk management. You should now review Coronavirus and HVAC. The Building Services Engineering Association have recently introduced new guidance which has been built with the help of REHVA – the Federation of European Heating, Ventilation and Air Conditioning Associations with additional content from CIBSE – the Chartered Institution of Building Services Engineers and BESA – the Building Engineering Services Association.
Changes to building services to support COVID risk management
One of the key elements of advice for Coronavirus and HVAC concerns recirculation of air. Under normal circumstances, some workplaces may see just 20% fresh air in normal operation in cold temperatures. Whilst the environment would normally dictate that this is good practice to conserve energy usage and lower carbon emissions our new normal will change this. If you are running recirculating air the new advice is to run at 100% fresh air and no recirculation as to recirculate air would introduce the potential for increased viral load.
Another change is to ensure that systems are running before and after occupation to further increase air changeover, 2 hours before and 2 hours after occupation where practicable. Outside of this systems may be kept running at a reduced speed to continually change over the air within buildings – this would include overnight and at weekends. Some larger clients may have automated systems with a sensing CO2 set point. If this is set to 400ppm (closer to a typical value for outside air) then this will ensure that fresh air is introduced and recirculation is minimised.
We are aware that not all of our clients are major employers which operate such complex systems. In these cases the simple act of opening windows and reminding users that typical wall and ceiling mount A/C systems simply recirculate air is best practice. this may increase thermal discomfort but most staff will appreciate the method behind this when told. Similarly, those in production environments may also see a benefit in increased air throughput from leaving external doors open but this does need to be risk assessed on a site by site basis.
For toilet facilities, you may wish to close external windows but keep extraction running continuously to create a negative air pressure for comfort and safety. It is wise to flush toilets with the lids closed to reduce airborne particles.
Maintenance works for HVAC systems: Coronavirus and HVAC
You should also be aware of the potential for increased risk when inspecting, duct cleaning, replacing filters and so on. In the current situation, these filters should be treated as contaminated and staff protected accordingly and good hygiene practised. All filters should be double bagged before disposal.
Good practice for those with fan coil heater exchangers would be to run these in full heating mode once per day ensuring that the fan coil reaches 60oC for at least one hour to deactivate any virus accumulation.
We would caution that we are not HVAC Engineers but the above guidance and the information available at this link is a good starting point for clients. We would suggest using the above information to request further detail from your contractors or FM partners to ensure you are doing all you can to help control COVID exposure.
We hope that this information helps you. If you have any questions relating to Coronavirus please contact your retained safety consultant if you are a member of our Safety~net competent person service. We have a number of documents available for retained clients including model risk assessments, flow charts on isolation, administering first aid and home working, toolbox talks for office-based and field-based staff and similar documents which are being developed each day. We’re still open, our phone lines are live and we’re ready to help when needed.
- Coronavirus Risk Map (PDF): Download a copy here
- Coronavirus Risk Map (PNG Image): Download a copy here
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- Coronavirus Risk Assessment
- Coronavirus: Cleaning your workplace before re-occupations
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- Coronavirus face masks: are they effective?