With some maintenance, an Air Conditioning System should last about 20 years. They usually last a little longer than a Heat Pump, because the compressor only runs in the summer. I usually recommend replacing your Air Conditioning System when a major problem comes along, like a compressor failure. New Systems come with a 10 year Warranty. Higher Efficiency Equipment is available today than in years gone by. Call Foothills Mechanical Service, we will help you select a new High Efficiency Air Conditioning System that will reduce your Energy Bills.