I am interested in getting feedback on high velocity air handlers from both a tax credit and feasibility perspective. We are seriously considering installing a Geothermal system in our 70 year old home. The majority of the quotes we have received are for a split sytem - a 3 ton unit for the first floow and basement and a 2 ton system for the top 2 floors. We have primarily focused on WF Envision equipment. The house is currently heated by steam, thus there is no ductwork for the first floor. The upper floors were retrofitted with central air and thus have ducwork in place. A friend up in PA just had a Geo unit installed. He had similar ducting issues and his contractor recommended and installed high velocty air handling and it worked out very well for them. I was considering the same for serving our first floor as it would greatly reduce space constraints in our basement as compared to conventional ductwork. However, I have heard that using a high velocity air handler with the Geo System would negate the 30% federal tax credit, since the air handlers are not energy star rated. I have looked on various web sites and have seen very diverse feedback on what can be deducted on the Federal tax credit. Any thought on either including a high velocity air handler in the tax credit application or overall practicality of integrating this system with a Geo unit (beyond my sample of one)? Thanks!