In my quest for Geothermal, I've heard various different slants on retrofitting my existing home. One thing that has me wondering is the variable speed blower motors. One installer claims that a variable speed blower will save me money in the long run because it's more efficient. Another claims that with the existing duct work in my home that there won't be enough volume on the lower speeds to heat the house evenly, and that it will end up at the higher speeds anyways. What do you guys think? Thanks!!