"It is true that air conditioners have a long life but like all other appliances air conditioners also does not perform properly after a point of time. When such a time comes, it is a better idea to replace the unit because continuing with an inefficient system will shoot up the energy costs. But one should know the right time to replace the system.For instance, when the air conditioner is more than 10 years old, it is obvious that the unit will not be able to function properly and as a result it will have to work hard which in turn will pull up the utility costs.Secondly, when you realize that your air conditioning unit requires frequent repairs, one should understand that it is better to opt for a new system altogether instead of investing on multiple repairs. Lastly, if you think that you are interested on more energy savings, it would be a better idea to replace the old air conditioning unit and invest on a new system. This is because; a new system will use lesser energy and help you to save on energy costs."