Air conditioning efficiency tips suggest leaving inverter units on overnight to save energy

Installer Carlos Llull calculated that running a 1.5‑kW inverter air‑conditioning unit for eight hours overnight costs about €1, based on a night‑time electricity price of €0.13 per kWh. Keeping the unit on avoids the high‑power start‑up spikes that occur when the system is switched off and on, which can increase consumption by up to 50 %.

For two‑room homes, experts recommend a multisplit system instead of a single split unit. A multisplit connects two indoor units to one outdoor compressor, allowing each room to be cooled independently. This reduces unnecessary cooling, improves comfort, and can lower overall energy use, although the initial installation cost is higher than a single split system.