The point of the product is to restore lost efficiency. A new system is more efficient brand new. Over time heat transfer units lose capacity to transfer heat, thereby causing the compressor to work longer and harder. The older the machine, the less efficient. As for comparison, what else...
I had a rep from Compress Shield give me these two reports and they are good tests done by an independent engineering firm and one by the Florida DOE.
http://www.compressshield.com/v2/files/enduserreports/Mobil_Orlando.pdf...
