Carlos Llull, air-conditioning technician: Sleeping all night for less than a euro is possible

Carlos Llull, a climate technician known online as @soycarlosllull, has sparked widespread interest with a recent experiment demonstrating that sleeping through the night with air conditioning can cost less than one euro. The post, which quickly went viral, was shared on his Instagram account and has amassed millions of views. As temperatures rise across Europe, many have questioned how much electricity is really consumed by air conditioners during extended periods of use. Llull’s experiment aims to provide clarity on this issue using real-world data. The experiment began after Llull noticed doubts among users regarding his earlier claim that cooling costs under a euro per night. To address these concerns, he purchased a domestic energy meter, available for under 10 euros, and connected it directly to the power outlet of his air conditioner. This allowed him to measure the actual consumption over eight consecutive hours. His goal was to show that the cost of running the appliance overnight could indeed be significantly lower than commonly assumed. Llull used a conventional split-type air conditioner with approximately 2,500 British thermal units (BTUs) of cooling capacity, roughly 15 years old. He emphasized that while the unit is not the latest model, it still provides a reliable baseline for measuring average household usage. After leaving the device running throughout the night, he checked the meter the following morning and found the total energy cost to be just 0.32 euros. This equates to a consumption of less than three kilowatt-hours (kWh), far below the one-euro threshold that many had previously imagined. He explained that the result depends heavily on the local electricity tariff. In his case, he uses a three-period tariff, with nighttime rates around eight cents per kWh. While the calculation includes only the energy consumed by the appliance itself, he noted that utility bills typically include additional charges and taxes. Therefore, even when considering all factors, the cost remains well under one euro. Despite being conducted in Spain, the experiment has generated interest beyond national borders. Users from other countries, including Argentina, have expressed curiosity about how the findings might apply to their situations. They recognize that the final cost will vary based on local tariffs, equipment efficiency, and usage patterns. For example, in regions with higher electricity prices or older, less efficient units, the cost could increase. Llull also highlighted the importance of understanding how appliances consume energy. He encouraged individuals to check whether their devices are connected via standard sockets, as some models may require specialized wiring. By doing so, anyone can replicate the test at home and gain insight into their own energy habits. This approach empowers consumers to make informed decisions about their electricity usage, potentially leading to more sustainable practices. As the summer season approaches, the relevance of such experiments becomes increasingly apparent. With rising temperatures and growing awareness of energy costs, knowing how much electricity is actually used by common household appliances can help families manage their budgets more effectively. Llull's work serves as a practical guide, offering both scientific accuracy and actionable advice for everyday users.