Hello its me again, If i'm becoming a pain in the rear please let me know. After talking to you guys (thanks again) I think i'm going to go for the zoning. A couple more questions if you don't mind.I have 2 controllers in mind, the Zonex and the Smarthome. I kind of like the Smarthome better maybe because of the ease and info of the controller on their website. Anyone ever use this product or recommend any others. Is the short cycle protection for the a/c a standard in all controllers. Does that mean lets say if the therm only calls for 5 min of cooling, the controller will run it for 15min so it wont short cycle? And is a bypass damper important so there wont be a strain on the motor when only one zone is open? Am I correct in saying these are the 2 biggest problems with a zone retro? I do have a pretty decent unit ( from what i've been told) with a variable speed furnace and a two speed a/c. I am a little scared to go ahead because I do hear some negatives from people, but if I do my homework I should be fine. A friend of mine just put a large addition on his house and had his friend (the hvac guy) install a damper to zone the upstairs and downstairs. When I asked him if he had a dump zone or a bypass he kind of looked at me funny and said " naw you dont need that", could this shorten the life span of his equip?My wifes cousin is visiting from NY state tomorrow and he is an hvac guy, hopefully I can get his "blessing and get started". Thanks again for all the help.