Netherlands: Nighttime fan and air‑conditioner energy costs and cooling limits

Running a fan overnight in the Netherlands costs about €0.08‑€0.10 per night, based on an average consumption of 0.05 kWh per hour and a projected electricity price of €0.21 per kWh. By contrast, a typical single‑split air‑conditioner uses around 6 kWh for an eight‑hour night, costing roughly €1.92, while larger multi‑split units may consume up to 12 kWh, raising the nightly bill to about €3.84.

Scientific research cited indicates that fans cease to provide cooling when ambient temperatures exceed certain thresholds, which also depend on humidity and the user’s age. The UK government warns that fans become ineffective above 35 °C, and the World Health Organization notes a 40 °C tipping point where fans may actually warm the body. Experiments show that at 45 °C and 15 % relative humidity, fans can increase heat load, whereas at 38 °C with up to 60 % humidity they may still cool. Older adults may experience reduced benefit at lower temperatures due to diminished sweating.

These findings suggest that while fans are a low‑cost cooling option, their effectiveness is limited under extreme heat and high humidity, and using air‑conditioners incurs significantly higher electricity expenses.