Ventilation – Reopening Museums Toolkit

Updated 22/07/21

Ventilation has become something all museums need to think about now, as the risk of transmitting the virus is higher in poorly ventilated areas. The law has always required that employers make sure there’s an adequate supply of fresh air in enclosed areas, but this is more crucial now than ever and this can be challenging if your museum is located in a historic or small space.

Ventilation is just one of a range of measures used to control the spread of viruses, and its use should be balanced against other negative impacts such as increased pollution, energy, noise, security, health, well-being and environmental conditions.

The government has outlined the following advice in Step 4 of the roadmap:

‘Operators will still be encouraged to use outside space where practical, and to consider the supply of fresh air to indoor spaces. Carbon dioxide (CO2) monitors could be used to help identify where a space is poorly ventilated with businesses encouraged to take steps to improve ventilation if CO2 readings are consistently high.’

If opening up windows or doors to improve the ventilation in your museum to prevent the spread of Covid-19, consider if this has an impact on the security of your site and if additional measures such as increased invigilation will be needed. Be aware of where water ingress may be an issue if it rains, and have a plan in place to close any relevant windows/doors if it does. Keep an eye on any environmental monitoring and consider if windows need to be closed when it is damp outside and the relative humidity inside is getting higher. Opening windows may also increase the ingress of insects, birds, dust and pollution. Consider if some windows have a higher risk of this than others (for example a window above a busy street or a frequently used gravel path will let in more pollutants and dust).

Insect pest management (IPM) should also be carried out to monitor for a potential increase in insect activity. If an increase is seen, action needs to be taken quickly to deal with any infestations. If your windows have UV absorbing film on them then remember that opening them will allow UV light in. In this case any objects sensitive to UV damage (textiles, watercolours etc.) may be best moved or covered.

You will need to consider your environment carefully and make sure you are assessing all of your needs as well as the risk of infection.

Maximising the fresh air in a space and this can be done by:

  • natural ventilation[8] which relies on air flow through windows, doors and air vents that can be fully or partially opened;
  • mechanical ventilation[9] using fans and ducts to bring in fresh air from outside, or a combination of natural and mechanical ventilation, for example where mechanical ventilation relies on natural ventilation to maximise fresh air.

By ensuring that ventilation is increased, you will be reduce the risks of transmission as part of making your workplace COVID-secure.

Questions to ask yourself

  • What common-sense approaches can you take to improve air flow in your space? This could be as simple as opening the windows or ensuring that doors are kept open during visitor hours and when staff and volunteers are in the building.
  • If you have a challenging space where ventilation has been an issue before, can you consider changing the route around that space to help people stay in well ventilated areas?
  • Can you make use of other areas in your building, such as outdoor spaces if you have any?
  • How will improved airflow effect you staff and volunteers? Will you need to remind them to wear warm clothing, or even use this as an opportunity to provide them with branded jumpers or fleeces?
  • How will it effect your collection items? Will you need to keep a closer eye on your environmental monitoring for temperature changes and pests that might be more likely to come inside?
  • Are your collection items on open display or packed/in secure cases? Extra layers of protection will help to buffer negative effects of increased ventilation on their conservation (such as changes in temperature, exposure to light levels and pollution).
  • What security implications might you have to consider – and can you mitigate these with additional security measures?
  • If you think the risk to your objects is too great, could you think about holding them in another area where their conditions will be more beneficial? Would this mean removing those items from display for a short time, and if so, is that something your visitors would be happy with?
  • Consider doing a risks versus benefits analysis of the benefits of ventilation on the Covid risks versus the risk to your collection/site.

“Fresh air impoverishes the doctor.”

Danish Proverb



HSE Ventilation and air conditioning during the coronavirus (COVID-19) pandemic guidance

Natural ventilation

Mechanical ventilation

Advice from Historic England

Environmental information for the Government Indemnity Scheme

Government guidelines on ventilation

Gov/HSE guidance on Ventilation and air conditioning during the coronavirus (COVID-19) pandemic is at Ventilation and air conditioning during the coronavirus (COVID-19) pandemic (

NMDC Museum Good Practice Guidelines were updated in April to include information on ventilation Nmdc Good Practice Guidelines For Reopening Museums – National Museum Directors’ Council Website ( Page 18/19.

Briefing note on CO2 monitoring and monitors

Appendix 29

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