ASHRAE revises HVAC construction manual on heat pumps
The American Society of Heating, Refrigerating and Air-Conditioning Engineers released its newly revised manual, Geothermal Heating and Cooling: Design of Ground-Source Heat Pump Systems.
The new book was written by Steve Kavanaugh, professor emeritus at the University of Alabama, and Kevin Rafferty, a consulting engineer in Klamath Falls, Ore. Both have spent the last 25 years focused on geothermal work.
“One of the realities of the GSHP (ground source heat pump) industry is that, to some degree, it has been a victim of its own success,” Rafferty said. “Years ago the struggle was to simply get design teams to consider using the technology. Though this is still an issue in some areas, nationally it is far less of an issue than 20 years ago. There is now fairly wide recognition of the benefits of GSHP systems, particularly on the part of building owners in the schools and office building sectors, where the technology has achieved its highest penetration rates. However, there also is a widely held view that anything bearing the name ‘geothermal,’ ‘ground source’ or ‘earth energy’ will produce the desired high efficiency/low operating cost. As a result, poorly designed systems are often installed and building owners expectations are unmet.”
The book provides benchmarks, design strategies and information necessary for engineers to configure the most efficient and cost-effective systems and avoid problems such as inefficient pumping, high-cost ground loop designs, inadequate outside air provisions, complex control schemes and other common design errors.
“GSHP produces superior HVAC system performance and when properly implemented can be cost-competitive with many — but not all — conventional systems,” Rafferty added. “They can be operated with far simpler controls than traditional HVAC systems, and also can reduce equipment building space requirements, reduce ductwork requirements and eliminate the need for external building mechanical equipment.”
As part of the revision, seven of the original eight chapters and appendices were completely rewritten and now include coverage of close-loop ground (ground-coupled), groundwater, surface water, equipment and piping. Additional information on site characterization has been added including a new hydro-geological chapter. The final chapter was replaced and the new section contains results of recent field studies, energy and demand characteristics and updated information on system cost.
The revised heat pump book is available for $128 and $109 for ASHRAE members, at www.ashrae.org/bookstore or (800) 527-4723.