With the great heat here is Enea's advice for using air conditioners well

 The arrival of the great heat, with temperatures above 30 degrees, often triggers the rush to air conditioners. But to make them work at their best, Enea provides 10 practical tips that allow you to obtain environmental benefits and savings of up to 7% on the total electricity bill. The first suggestion concerns the choice of air conditioner. Models in energy class A or higher are preferable. A new class A air conditioner consumes approximately 30% less per year than an old class C model. Air conditioners with inverter technology are more expensive than those with on-off technology, but they consume less energy and are preferable when you plan to keep the air conditioning on for many hours at a time. To purchase a heat pump air conditioner, if it is intended to completely or partially replace the old heating system, you can take advantage of the home bonus, the ecobonus and the Conto Termico 2.0. It is important to place the air conditioner in the upper part of the wall: cold air tends to descend and will mix more easily with hot air, which tends to rise. According to Enea, it is not necessary to set the air conditioner to very low temperatures. Two or three degrees less than the outside temperature are sufficient. Often the "dehumidification" function can be sufficient: humidity makes the temperature seem higher than the actual temperature. Installing a powerful air conditioner in the hallway hoping that it will cool the entire house is useless. It only cools the hallway. Each room needs its own air conditioner. It is important not to leave doors and windows open: they let hot air in and force the appliance to work extra hard, with a consequent waste of energy. The refrigerant circuit pipes outside the house must be insulated. If they are exposed directly to the sun's rays, they risk being damaged. It is also advisable to make sure that the external part of the air conditioner is not completely exposed to the sun and weather. It is advisable to use the timer and the 'night' function, to reduce the time the appliance is turned on to a minimum. It is better to avoid leaving the air conditioner on all day, but only when you are at home. Finally, the air filters and fans must be cleaned at the first seasonal start-up and at least every two weeks: this is the place where mold and harmful bacteria frequently nest. It is also important to check the tightness of the gas circuit