By, Doug Carruthers 
In 2009, Geo-Connections, Inc. finished work on the complete rewrite of the IGSHPA Residential and Light Commercial System Design & Installation Manual. The goal was to create a comprehensive reference source for the geothermal heat pump industry based on sound scientific and engineering fact learned through our more than 50 years of combined professional experience.
Ryan Carda, one of the manual's co-authors, answers some questions about the new manual in the interview to follow.
Why write this new geothermal design & installation manual for IGSHPA?
When IGSPHA first contacted us to see if we would be interested in writing the new manual, we knew the task would be a huge undertaking. But we also knew it would give us the chance to serve a great need in the industry.
Our livelihoods depend on the success of the industry as a whole, so we wanted to create something that would help push it to the next level. Geothermal heat pumps are becoming more mainstream and as new companies jump in, they will need a guide to help them along the way.
How does the new manual differ from the older version?
The old manual served as a decent installation guide for many years but as time passed, the industry evolved. Also, there wasn't a lot of concrete information in the old manual that was related to the actual design procedures you need to follow when sizing a ground heat exchanger.
An abundance of great information did exist, but it was scattered in so many places, it was hard to find. We tried to pull all of that information into one place and then present it in a manner that would be fairly easy to understand. This manual is by far the most comprehensive guide available for all things geothermal: installation, design, system troubleshooting, economics, etc. Just about anyone could take something from this manual, engineers, contractors, and well drillers alike.
How might the new material help people and companies in the industry?
As new companies come to the industry and try to get their start, they will be exposed to countless rules-of-thumb, general guidelines, etc. The problem with that lies in the fact that newbies won't understand where these rules of thumb came from and which situations they work for or where the exceptions exist. The new manual was written so that if used properly, no one would have to rely on secondhand rules of thumb.
As an industry, we need to be as competitive as possible. There isn't much room for error. Also, if someone really takes the time to read through the presented material, they'd see that geothermal heat pumps aren't nearly as intimidating as they seem to be at first glance.