Some of you are aware that I have a pretty good energy monitoring system for my residence that, among other things, watches in real time the operation of my 2 GSHP units, and even warns me when some things are not performing correctly (see
http://www.welserver.com/WEL0043 ).
I recently did an upgrade to my monitoring system. One result is improved display of actual and carefully measured COP and EER. Real time display of COP and EER are now aligned with what mode the units are in (heat for COP, cooling for EER).
A key item is I now have a chart showing historical COP and EER actual performance (COP isn't present right now due to being exclusively in cooling mode down here in our now hot Dallas climate). My EER for my 5 ton WaterFurnace Envision 2 stage variable speed GSHP unit can be seen to range between 23 and 20 BTU/W.
The EER chart is the next-to-last chart in the series of charts at the above web site location.
Just FYI to illustrate the actual EER of a WaterFurnace Envision product that's 3 years old, and to illustrate that there's pretty good low cost monitoring technology products now available today that makes measurement and display of EER and COP relatively straight forward.
Best regards,
Bill