On November 7th, 2012 we made an update to LoopLink and wrote a quick post titled Making a Fair Comparison. The purpose of the original post was really just to let our users know that we had integrated an air source efficiency adjustment calculator into LoopLink.
After review, we realized that the post could and should be expanded into a more detailed discussion of the how and why of air source heat pump efficiency adjustment. So, we expanded the original post into a very handy PDF now available for download through the Geo Bookstore.
Free Download: ASHP vs. GSHP: Making an Apples to Apples Comparison