Health, environment, price: each device has its advantages and disadvantages. Here’s what the science says.
You will also be interested
[EN VIDÉO] Heat wave or heatwave: what’s the difference? In summer, we hear about heat peaks, heat waves and heat waves. The difference is not obvious, but it does come into play for weather alerts or health vigilance plans.
With the global warmingthe waves of heat are called to multiply. The heat wave of 2019 in France is thus 10 times more likely to recur due to climate change due to human activities. However, these heat waves are by far the extreme weather events the deadliest in most parts of the world, recalls Friederike Otto, researcher at the University of Oxford (United Kingdom). So how do you cool down effectively, without breaking the bank or making the warming worse?
Health: the ventilator effective in 97% of cases
One of the first reflexes to cool off is to use a fan. However, when it is very hot, the latter is no longer enough: it brewsair warm and increases the feeling of warmth. Worse: by wicking away sweat, it prevents the evaporation process that can cool the skin. The World Health Organization (WHO) thus recommends not using a fan above 35°C, and in communities, the government advise against its use in closed environments where there are several people. ” Above 34°C, none debit of air is not enough to lower the sensation of temperature by more than 0.5° C “, Explain a study published in 2013.
Yet, according to a study from the University of Sydney, these recommendations are exaggerated. According to the modeling researchers, the danger threshold is rather above 39°C for healthy young people and 38°C for the elderly (whose body cools less easily). ” In 97% of cases, the fan is sufficient and beneficial “, conclude the authors. During strong extreme heat waves, it is always possible to take refuge in an air-conditioned place such as a shopping center, a cinema or other public places.
Environment: air conditioning uses 50 times more energy than a fan
With the proliferation of heat waves, sales of air conditioners fly around the world. According to the International Agency forenergytheir number should increase by more than 50% over the next ten years, before exceeding the milestone of four billion units by 2040. However, air conditioning already contributes 10% of global electricity consumption. Although the fans also work with electricity, they are much less energy consuming. ” An electric fan requires 30 to 50 times less energy than an air conditioner to operate. “recalls Ollie Jay, researcher at the University of Sydney. Note that the two systems are not mutually exclusive. A fan allows reduce the temperature by 4°C when used in conjunction with the air conditioning, which therefore makes it possible to reduce its consumption.
Price: the fan 50 times cheaper to use
Installation of an air conditioning system home is no small feat. For a one-piece air conditioner, it is enough to provide an exhaust duct for the hot air, but a split air conditioner consists of at least two units (one outdoor and one indoor), connected by a pipe. On average, it takes 100 to 200 euros for a one-piece system, and 800 to 1,000 euros for a mono-split and 500 euros per additional unit. A table fan costs between 20 and 50 euros, and for a column fan, count between 50 and 200 euros.
Also pay attention to the cost of use: 1 kWh of electricity costs about 15 euro cents per hour. A small 2,500 W fan used 4 hours a day will therefore increase your monthly electricity bill by 45 euros. For a same duration Typically, the price of a 50 W fan will be 90 cents.
Interested in what you just read?