We have only had this air conditioner 3 years. The air runs well at first. It keeps our house cool. Then eventually starts running loudly. The house does not stay cool. And they outside lines freeze over. We have kept up with all maintenance. The company that we bought from cant find the problem. We even had the ducts cleaned. They say we have another 5 years before we might have to replace the furnace. So, its not that. There is no problems with leaking Freon. So, any suggestions as to what the culprit is ?