Has anyone installed temperature sensors when installing their loops so that they can gauge ground temperature post-installation? Any suggestions on the sensors themselves? Manufacture/type? I assume I will need to have them "wired" and thus installed now with the trenches opened. Thoughts?
if you put a temp sensor in a trench which is next to/very near the piping, you are effectively going to get the water in the pipe temperature. I would forgoe that and just measure incoming water temp in the pipe. On the otherhand, if you want to know true ground temps, you probably need to put multiple sensors at different distances away from the pipe at different locations along the pipe length. The ground loop is one big averaging mechanism - no 2 locations will read the same (say analyzing the trees) and I would argue you really only care about the incoming and outgoing water temps at the heat pump (analyizing the forest).
I would agree with @gsmith22. I could see a loop sensor being useful if you had multiple loops, each with a sensor, and you wanted to detect whether a given loop had zero flow. That shouldn't happen with a properly installed and flushed system though.
