I am new to geothermal heating/cooling and have been trying to educate myself. So I have a question for the experts about the variation in entering water temperature from a vertical loop over a season. For a vertical loop, how much of the temperature variation is due to the heat being added/removed to/from the loop field, and how much variation would be there without any loop heat being added/removed by the load? For example, look at the EWT_source graph from this pair of 400 ft wells - http://welserver.com/WEL0383/ (3rd graph from bottom of page). This shows a sinusoidal like yearly variation from around 50F in summer to around 30 F in winter. So my question is, if the heat pump were not running (but the circulator was - so that the EWT = LWT = average temp along the well), what would this graph look like (e.g. still a sine like wave, but with a mean of maybe 60 F, and peak maybe in august of around 61F- 62F)? Thanks for responses.