Of major appliances, central air conditioners suffer most from poor maintenance. Yet investing just an hour or two of cleaning time will not only ensure your unit will be functional when you need it, but will also save money in operating costs and extend its life. Dust that collects on compressor cooling fins is the No.1 problem. The solution is to follow the manufacturer's instructions to vacuum interior coils and fins every spring, and to change the filters by mid-summer. Keep your air conditioner clean and well-lubricated, and you'll have relief all season long. And that's the On The House tip for today.