Being kept clean is what keeps air conditioners going. Of all major appliances, central air conditioners suffer most from poor maintenance. Yet investing just an hour or two of cleaning will not only help ensure your air conditioner will work when you need it, it will save money in operating costs and extend its life, as well. Dust that collects on compressor cooling fins is the No. 1 problem. The solution is to follow manufacturer instructions to vacuum interior coils and fins every spring, and to do it again at mid-summer. Change the filters, too. Keep your air conditioner clean and well- lubricated and you'll beat the heat all summer long. And that's the On The House tip for today.