I asked this question in the Residential Forum but didn't get a very good response, so I hope some of you guys can help me. I'm going to install a 3 ton Heat Pump and AHU system in my own house soon. I'm going to get a Carrier/Bryant/Payne system and was thinking of getting a variable speed AHU. I work on Commercial equipment and don't see a lot of Residential units, so I need your advice. Do the variable speed blowers work good or should I go with a 2 speed blower. My Service Manager told me that a lot of guys are having problems with the variable speed units and parts are much higher. He said that if the duct work is not sized just right, the blower doesn't know what speed to run at. Thanks for any advice you can give me.