Fans aren’t a panacea to beat the heat like college show modeling is

A new study by researchers at the University of Ottawa throws cold water on the idea that fans can effectively cool you down during extremely hot weather.

As severe heat waves become more common due to climate change, there is a growing need for safe and accessible ways to keep people cool, especially vulnerable populations such as older adults. Fans are often recommended as cheap and easy solutions, but this research shows that they may not be as useful as previously thought.

Postdoctoral researcher Robert Meade led the study, which was conducted at the University of Ottawa’s Human and Environmental Physiology Research Unit, a unit led by Dr. Glen Kenny, professor of physiology at the Faculty of Health Sciences.

“Fans improve the evaporation of sweat, but this effect is not strong enough to significantly lower your body’s internal temperature when it is already very hot (above 33-35°C). In older adults, who may have reduced power to sweat, fans provide even less cooling benefits,” Meade explains. “In fact, even in younger adults, fans provide only a small fraction of the cooling power of air conditioning.”

The study recommends that health organizations continue to advise against relying on fans during extreme heat, especially for older adults and other groups at higher risk for heat stroke and other adverse health events during heat waves. Instead, the focus should be on providing access to alternative cooling solutions, such as air conditioning, and exploring ways to make these options more accessible and environmentally friendly.

The research was conducted using human heat balance modeling techniques developed in 2015. By extending these models to estimate core temperature under a range of conditions and modeling assumptions, the authors were able to compare the expected effects of fan use under a wide range of conditions. scenarios.

“The results from the 116,640 alternative models we produced in sensitivity analyzes indicated that fans are unlikely to significantly reduce core temperature at high temperatures or match air conditioning cooling. Comparisons with more advanced modeling techniques and laboratory heat wave simulations supported this conclusion” , Meade adds.

Fans are good at providing air circulation and may work in moderate temperatures, but are not as effective in extreme heat. Public health authorities have a role to play.

“Keeping indoor temperatures cool is important for vulnerable individuals, but cooling strategies such as air conditioning can be expensive and harmful to the environment. It is critical that we improve the accessibility and sustainability of air conditioning and other forms of ambient cooling to protect those in need,” says Meade.

“Fans can still play an important role in this, as they can cool effectively at lower temperatures, meaning we don’t have to turn our air conditioners down as low. However, when it gets really hot, a fan just won’t turn on. to cut it.”

The study, titled ‘A Critical Review of the Effectiveness of Electric Fans as a Personal Cooling Intervention in Hot Weather and Heat Waves’, is published in The Lancet Planetary Health.