Guidance contained in the Commissioning, Preventive Maintenance, and Troubleshooting Guide for Commercial Ground-Source Heat Pumps, published by ASHRAE (Atlanta), ensures proper operation of these systems. The guide includes commissioning requirements for GSHP systems in the design and program, construction and acceptance phases of a commercial project. To order, contact ASHRAE Customer Service at 800-527-4723 or visit the ASHRAE Online Bookstore at