Dear Readers: To cover or not to cover: That's the question I get asked this time of year by folks who have central air conditioning. Should you shroud that outdoor condensing unit? I like the idea, since it's so easy and inexpensive. Admittedly, these units are coated with weatherproof enamel paint and have self draining holes to get rid of melting snow and rain. But they will look prettier longer and probably last a few more years in service if they are protected form harsh winter conditions. You can buy an inexpensive plastic cover, complete wit