# Loop temperature

Discussion in 'Vertical and Horizontal Loops' started by LeakingLoop, Mar 4, 2014.

1. ### LeakingLoopNew Member

Does a closed horizontal loop get colder as winter passes because the cold temperatures are going further into the earth at the 4 to 6 foot level or because the geothermal unit has robbed the loop field of its heat energy as winter has passed?

Consider the follow example:

The amount of heat being taken from something as large as the earth is negligible compared to the small size of a geothermal unit. I think of it like this. It is like throwing ice cubes in a harbor in the ocean. The harbor represents the loop field, the ocean represents the earth. I could throw ice cubes in the harbor all day and night, and I really am not going to change the ocean water temperature in the harbor by a measurable amount. It would be a long shot to even bring the ocean water temperature in the harbor down 1 deg F with the ice cubes. I realize the heat conductivity of water is greater than soil, but still don't believe the amount of runtime a geothermal unit has can change the temperature of the loop field. Whether the unit runs 24 hours a day or 1 hour a day, the temperature of the loop field will always be the same temperature of the earth anywhere else in your neighborhood at that soil depth. Please give me your comments or opinions.

2. ### BergyMemberIndustry ProfessionalForum Leader

Depending on design, horizontal loops can swing between 30*~90* Winter through Summer.

Bergy

3. ### AMI ContractingA nice Van Morrison songIndustry ProfessionalForum Leader

If we are comparing harbors to a geo system, then you wouldn't be dumping a few ice cubes in the harbor you would be dropping in a baby glacier ( let's say 5 tons of ice). For those who don't know, a ton is the amount of btu's it takes to melt a ton of ice in 24 hours (12,000), then in an hour you are going to drop a second glacier in then the following hour..........so in 24 hours you are going to drop a hundred and twenty tons of ice in the harbor (that's a lot of cubes). Can you see that impacting the surrounding temp?
Now what if there weren't any currents or waves or underground streams? You have to get your heat through either solar contribution or heat migration which without any sort of circulator will happen but not very quickly.
It's slower with dirt. As you point out the earth has a whole lotta heat however, so inspite of this 120 ton glacier in the back yard (each day!) I can still heat my home.

Bergy likes this.
4. ### Mark CustisNot soon.Industry ProfessionalForum Leader

Joe:

Your mind's working make me smile.

Check the latest from Caleffi, it includes your favorite t-stat.

Mark