AboutFraser Hamilton Expertise I have over 15 years of professional experience in the environmental geology field. I am well versed in general geology types of questions and answers. In addition I have a keen understanding of physical stratigraphy (especially in the Valley and Ridge of Central PA) and cycles.
Experience Eight years of education, fifteen years of professional experience. Have worked or studied in ME, PA, TX, KY, IN, TN, OH, WA and Scotland.
Publications Geological Society of America
American Association of Petroleum Geologists
Properties Magazine
Cleveland Bar Association
Cleveland Engineering Society
Education/Credentials BA Geology/Math, University of Maine at Farmington
MA Geology - Physical Stratigraphy, Temple University
Post Grad Studies Geology - Texas A&M University
Awards and Honors Distinguished graduate teaching award, Temple University
Question I read somewhere that almost any place in the world if you dig 3 feet below grade it should be about 55 degrees F. so I dug 4 feet and placed a plastic tube under ground to take advantage of this temp for air conditioning. I only was able to get 62-65 degree temps back.so I dug a ditch about 14 ft and attached a sensor and it is only 62 degrees. I am in Wind Gap Pa.how deep do I have to go to get 55 degrees and is it a constant in most places?
Answer Bruce:
The theory is good. This is the whole basis of geothermal heating systems that use deep wells (50-100 feet I think) to recirculate fluids that are cooled by the constant temp in the summer and warmed in the winter when the ambient temp at the surface is colder than that at depth.
I honestly do not know the precise depth. But I do know it is not 3 or 4 feet. The frost depth where you are is probably 3 feet. That is, in the winter it is probably that if you filled your pipe with water at 3 or 4 feet it would likely freeze.
It should be fairly constant in your location once you reach the required depth. There comes a point where it starts to get hotter though. I suspect you need to find some a local mechanical engineer with experience in geothermal heating/cooling systems to help you.
