Ventilation and air conditioning in the workplace

You can improve natural ventilation by fully or partly opening windows, air vents and doors. Don’t prop fire doors open.

Buildings are usually designed to provide adequate ventilation. You should be able to open any windows or vents that let in fresh air. If they cannot be opened, ventilation in that area will be less effective.

If you identify an area that needs improvement, you should decide if it’s safe for people to use that area before you make any changes.

Don’t close doors or windows completely when people are in a naturally ventilated area. This can result in very low levels of ventilation.

Airbricks and ventilation grids need to be kept clean, so that the air supply is not obstructed, and where possible open any trickle vents in your workplace.

Cooler, windier weather increases natural ventilation through openings. This means you don’t need to open windows and doors so wide.

We have more advice on balancing ventilation with keeping workplace temperatures comfortable.

The Health & Safety Executive in Great Britain have produced guidance on improving ventilation in the workplace.

Purging (airing rooms)

Airing rooms as frequently as you can improves ventilation. Opening all the doors and windows maximises ventilation in a room. It may be better to do this when the room is unoccupied. The use of a CO2 monitor will help you judge how long it takes to purge the air in a room.

Talking to your workers about improving ventilation

Making sure that an area has enough fresh air relies on your workers playing their part. You should explain the importance of adequate ventilation to your workers.