Pure Electric provides wealth of information and we'll respected advice on various internet sites. When we moved into a house which was 10 years old, with 7m square main kitchen)dining/living room, heated by larger 7.5kW split system, we monitored power consumption for a full year. It averaged less than 10kWh per day, so less than 10% run time, hopelessly oversized. Did ask local Daikin dealer for price on Ururu but he insisted he needed to visit before quote. Then insisting on knowing details of the room, he was abusive that the 2.5kW model was only good for tiny room. So we were happy to go with Pure Electric and even happier that on thermostat set at 18 for winter and 24 for summer, it consumes just 2.5kWh per day or 1279kWh in 644days. Its not a cheap gadget by up front cost but obviously pays for itself, big time, very happy customer.