Here's the scoop: I've been living in my new custom-built house now for 20 months. It has many west facing windows. We noticed in the summer after 3pm that the AC seemed to have difficulty keeping up. I called our AC installer to come out and look it over. He serviced it and added some freon and then told us of its condition: He says the coil in the air handler (RUUD) needs to be pulled and cleaned. There is dirt and/or mold on it. He wants to install a U/V light to prevent future mold troubles. Total cost will be about $500 for the coil and $800 for the U/V light. It has only been two years and seems a bit soon to be having these types of troubles. AC man says that changing the filter every three months (filtrete) is not often enough, plus with the handler in the attic in a humid environment is partially to blame. According to him the warranty is void because we did't have the unit serviced every six months. He claims to not be working on commissions. What do you think? Is this legit or is he trying to scam me or cover something up from the install? Is this something that there is a work-around which I don't know about? Is there something maintenance-wise I could have done to avoid this? I would really appreciate some feed-back on this from an informed impartial source.