People are being encouraged to improve ventilation in their homes by opening windows as part of a new coronavirus campaign.

A video released by the Department for Health illustrates how virus particles linger in enclosed spaces, but letting fresh air in can reduce the risk of infection by more than 70%.

Coronavirus is spread through the air by droplets and smaller particles known as aerosols when they are exhaled from the nose and mouth of an infected person as they breathe, speak or cough.

They move in a similar way to smoke but are invisible, and the majority of virus transmissions happen inside.

Indoors, the particles can be suspended in the air for hours and build up over time, and the longer people spend in the same room as these particles, the more likely they are to become infected.

With winter approaching and people spending more time at home, experts have recommended opening windows for around 15 minutes at a time regularly throughout the day, or leaving them open a small amount continuously.

The campaign, launched on Wednesday, also advises using kitchen and bathroom extractor fans as another method to remove infected particles from the home.

Public Health Minister Jo Churchill said ventilation is “essential” over winter.

She said: “As the weather gets colder and wetter, letting in fresh air in short burst helps to reduce the risk of coronavirus in our homes.

“We should all remember: open your windows, and Hands. Face. Space.”

Professor Catherine Noakes, from Leeds University who advised on the film, added: “When a room does not have any fresh air, and where people are generating large amounts of aerosol through activities such as singing and loud speech, that is when transmission of coronavirus is most likely.

“Fresh air must come from outdoors – recirculating air just means the aerosols containing the virus move around the same room rather than being extracted outdoors.”

Airing indoor spaces is particularly important when you have visitors, and if a member of the household has the virus it can help prevent transmission to other members.

The campaign film is part of the wider ‘Hands. Face. Space’ guidance, and was created with scientists and an engineer at Leeds University.