I have a 2 story home located in SC. The ground floor has a 16 year old Amana condenser that was added on to an even more ancient Marvair air handler. I have 2 q's: 1. On hot humid days there is a lot of condensate on my duct insulation. In places the insulation was wrapped very tight and it sweats the most there. How much condensate is normal(any?) under the circumstances. One heating man said I need more vents, another that I should close the vents altogether to avoid humid air coming in. 2. I am looking at replacing the entire system - would someone tell me an appropriate SEER value to choose for my area and whether I should definitely get variable speed air. What about 2 stage compression? I am getting a quote on a Goodman system, but I'm not sure Goodman makes a variable speed system for a crawl space application or has a 2 stage compression system. If you could guide me on what features are worth the money that would be helpful too. I am not interested in a lowball system, but I do want value. Thanks in advance - this is a super site!!!