Garen Ewbank – B.S. I.E.&M, OSU, AEE Fellow The GreyEdge Group

Phone: 580-227-2358
Mobile: 405-826-8156


Garen grew up in the water well and oil and gas drilling industries. Garen’s motto is “keep turning to the right”. Garen has worked in the GSHP industry since 1979 and has been involved in the design and implementation of well over 100,000 MW (millions of feet) of installed heat pump equivalent capacity in North America. Garen was a contributor to several training courses to include the Certified GeoExchange Designer Course and Syllabus that has been adopted by the International Ground Source Heat Pump Association (IGSHPA) and the Association of Energy Engineers. Garen is a member of the Technical Committee to develop the Bi-National CSA/ANSI C448 Standard for the Design and Installation of Ground Source Heat Pumps for Commercial and Residential Buildings. Garen is a founding member of the GreyEdge Group.

Areas of Expertise

Garen developed the in situ thermal conductivity testing methodology used by the GSHP industry to size and design ground heat exchangers (GHEX). Garen is co-owner of the patented Advanced Thermal Conductivity Method (ACTM) that shortens the testing duration and quantifies the diffusivity. Garen has installed GHEXs throughout the U.S. and consulted throughout the world on GHEXs. Garen has been a primary investigator/ collaborator on numerous applied research projects on the GHEX, borehole resistance and thermal storage, Garen has peer reviewed several software applications to size and design the GHEX. Garen trains for IGSHPA in all courses domestically and internationally.

Garen is managing member of Ewbank Geo Testing, LLC, member of GeoAire International and at large managing member for The GreyEdge Group, LLC.

Notable Projects & Achievements

Professional Affiliations and Publications