Wednesday, 29 June 2016: 11:00 AM-12:30 PM
HVAC Systems and Equipment
Chair:
Scott Hackel, P.E., Seventhwave
Technical Committee: 06.08 Geothermal Heat Pumps and Energy Recovery Applications
Space limitations and other constraints are forcing engineers to design deeper boreholes for ground-source heat pump systems in buildings. There are advantages and disadvantages to doing deeper than typical boreholes, and there are specific limitations on depth in some circumstances. This seminar covers these considerations, both through calculation and design examples, as well as practical lessons learned from the field. The new, deep/ultradeep borehole, hydrostatic differential calculations from the 2015 ASHRAE Applications Handbook are also presented. The latest developments in non-cementatious grouts are introduced to help designers avoid pipe collapse in deeper boreholes without sacrificing performance.
1 Installation Practices and Hydrostatics of Deep Boreholes
 |
Ryan Carda, P.E., Geo-Connections Inc |
Space limitations and other factors are forcing engineers to utilize deep boreholes to meet design requirements for GSHP systems. Hydrostatic pressures must be considered to safely complete deep, grouted borehole installation. Proper installation methods along with the necessary calculations will be presented. This session includes calculation examples using the procedures that were introduced in Chapter 34 of the 2015 ASHRAE Applications Handbook.
2 Swedish Practices and Experience with Deep Boreholes
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Jose Acuna, Ph.D., KTH Royal Institute of Technology |
This presentation covers a number of Swedish design and practical experiences and challenges when installing GSHP systems in densely populated areas. Deep borehole heat exchangers are a primary solution in these scenarios, and are the focus of this presenation. The presentation includes economic, technical and practical aspects. It also highlights ongoing research projects dealing with deep borehole heat exchangers.
3 Evolution of High and Low Density Geothermal Grouts
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Charles P Remund, Ph.D., GeoPro, Inc. |
Grouting is a critical part of closed-loop ground heat exchanger installation. It is needed for environmental protection, borehole integrity, as well as thermal system performance. This session covers the important aspects of grout properties, selection and installation, with a focus on the additional challenges that occur when boreholes are drilled deeper. This session also introduces the latest developments in bentonite-based grouts that are available to help the designer avoid pipe collapse in deeper boreholes, without sacrificing thermal performance.