Poland: Experts debunk home‑cooling myths and promote green walls as energy‑saving solution

Polish experts explain that several popular home‑cooling practices do not reduce electricity use and can even increase consumption. Closing air‑conditioning vents in unused rooms raises system pressure and can cause cooled air to leak through building gaps, nullifying any savings. Leaving a fan running in an empty room does not lower room temperature; it only cools occupants, and the fan consumes power without benefit. Setting an air conditioner to the lowest temperature does not speed up cooling, as units operate at a fixed capacity regardless of the thermostat setting, and overly low settings can lead to unnecessary energy use. Frequent switching off modern LED lights also does not lower energy consumption.

A separate study from Osaka Metropolitan University, led by Prof. Jihui Yuan, shows that vertical green walls installed on the south façade of an educational building in Shahrood, Iran, can lower indoor temperatures by up to 1.7 °C during heat waves. The greenery provides shading, transpires water that absorbs heat, and creates an insulating air layer, reducing the building’s reliance on air‑conditioning and easing strain on the electrical grid. Researchers combined building‑energy models with micro‑climate simulations to assess the combined effects, highlighting green walls as a viable, low‑energy strategy for mitigating urban heat islands.