Hello all, question for you. I have a horizontal loop field, 6 loops total. I believe they are 150' out and 150' in; however, I'm not 100% sure on that distance. I believe the trenches are 6 feet deep.

The field is supplying a Hydro Delta Mega Tek Quadra Therm geo unit. This unit has its issues. Ok, the unit has several issues (i.e. 3 compressors in 3 years). Not to digress though...

My question is this. I'm curious to know what the incoming loop temperature should be compared to the outgoing temperature. Currently the outdoor temp (Iowa) is hovering anywhere around 5 degrees to -5 degrees (not including wind chill). We've probably gone through a month of winter temps with this being the first real zero degree temps so far. Also my lines are insulated by a layer of 6" snow.

Two things.

First, my loop temp hovers around 38-40 degrees. Should the temp of the liquid nose dive that quickly? What would cause the ground temp to lower so quickly? Does that mean the straight layed geo field lines are too close? Or is this normal for the lines to chill so quickly?

Secondly, my incoming and outgoing fluid from the field is very similar in temperature. The difference between in and out is only a difference of 1.1 degree, or less in some instances (once it was the same at 38.7 degrees). What is normal? Or is this normal?

Thank you all for your time!

Hi,  sorry to hear about your HydroDelta woes. 

Some answers for you:

1)  A loop that is at 38-40° is working just how it should be for this time of year.  The  ground temp swings with the seasons and as you pull heat out of the ground, the loop temp falls below the  ground temp.


2)  Your incoming and outgoing fluid temps should have about an 6-8° drop when heating.  If there is little or no difference,  then your compressor is not working right. 

Hope this helps..

Good Luck and let us know