Aug 31, 2015

NGWA Publishes Guidance on Hydrogeology's Impact on Large-Scale Geothermal Heat Pump Systems

The guidelines provide a useful, ongoing reference for those involved in planning or site assessment for a large-scale GHP project

NGWA Understanding HydrogeologyLarge-Scale Geothermal Heat Pump

NGWA Press, the publishing arm of the National Ground Water Assn. (NGWA), released its newest title, Understanding Hydrogeology and Its Impact on Large-Scale Geothermal Heat Pump Systems.

Edited by industry experts Nina Baird, Ph.D., Carnegie Mellon University, and John Rhyner, PG, P.W. Grosser Consulting Inc., these guidelines bridge the gap between existing HVAC literature and geothermal heat pump (GHP) industry training, and provide a useful, ongoing reference for those involved in planning or site assessment for a large-scale GHP project.

While site geology and groundwater hydrogeology strongly influence the feasibility and cost-effectiveness of a GHP system, these are often the least-understood aspects of an installation. NGWA prepared these guidelines to support installation and ongoing operation of high-performance GHP systems with focuses on the protection of groundwater and the optimal performance of the wellfield.

Design and installation of a large-scale GHP system requires multidisciplinary expertise to evaluate underlying geology, climate, meteorology, hydrogeology, drilling conditions, the building loads, and the ongoing thermal interdependence that will affect the ground heat exchanger (GHX) and building systems simultaneously. Topics covered in the book therefore address:

  • Fundamentals of large-scale systems;
  • Site and hydrogeologic considerations;
  • Site constraints;
  • Site assessment and ground coupling options;
  • Drilling;
  • Regulations and requirements;
  • Professional qualifications for GHP system design and installation;
  • Characteristics of a successful GHP product; and
  • Common causes of GHP shortfalls.

Anyone who is considering or involved in the installation of large-scale GHP systems—including owners, planners, architects, engineers, drilling contractors, mechanical contractors, government representatives and educators—will benefit from this text.

“These guidelines present an approach to site assessment to help ensure the installation of an effective and long-term GHX installation that meets regulatory requirements, has an acceptable financial rate of return, prevents groundwater contamination, protects drinking water sources and public health, and protects the owners’ investment," said Todd Giddings, Ph.D., president of Todd Giddings & Associates Inc. in State College, Pa.