Depending on where you live and the climate there, an air conditioner might be necessary to help you through the warmer months of the year. Operation of an air-conditioning system is a lot like an automobile; efficiency depends largely on the way it's maintained and operated. Debris-clogged filters make the system work harder. Disposable filters should be checked every two months (once a month during peak use), and replaced when necessary. Permanent filters should be cleaned in accordance with the manufacturer's instructions. Periodic inspections during the offseason by a qualified heating and air-conditioning contractor can help keep efficiency up, utility bills down and extend the life of the unit. Insulation, weather-stripping, window coverings and shade trees also can be used to help your home beat the heat. And that's the On The House tip for today.