Getting drill rigs and excavation equipment onto a large schoolyard to install a GHX is usually easy to do. There's ample space to store materials on the site, space for site construction trailers and areas dirt from excavations can be piled. As larger GCHP projects are built on smaller sites, getting heavy equipment onto the site becomes much more challenging and expensive.
In some projects where the proposed building footprint covers the entire site, the only option has been to drill vertical boreholes under the building or, in some cases, embed GHX piping within the structural piles supporting the buildings. In existing building with little or no available land for the construction of a GHX, vertical can be drilled from inside the building itself, or drilling angled boreholes under the building. These approaches are generally more costly. Using an integrated design process with the building owner and design team is critical to optimize the size and performance of a GHX.
During construction a site is extremely busy and crowded. On a large project the various trades involved in the project will require a site office or site trailer. This should be considered before work on the site begins. Many trades must also store materials onsite during construction. This as well needs to be considered when the drillers and excavators are on site and the amount of space needed to maneuver heavy equipment is at a premium. Good coordination between the GHX designer, GHX contractor and site supervisor will minimize interference between the trades and the GHX installation crew.
Consideration must obviously be given to where the building itself is being built, but existing and proposed underground services must also be considered. Water lines, sewer and storm sewer lines, lighting standards, power and communication cables must also be considered and coordination between the civil engineers is imperative.
Drilling and excavation is very intrusive on a site. Some drilling methods and geological conditions can produce a great deal of ground water and drilling mud when drill rigs are in operation. On a small site, understanding how to deal with the potential mess on a site will make the process much simpler.
Some locations can be impacted by adverse weather in some seasons. Cold and rain can delay the operations of excavators and drillers, making the site less accessible during some seasons. Considering the timing of the installation can make the installation of a GHX more feasible.
In my blog I'll be expressing my opinions about what I've the learned about ground coupled heat pump (GCHP) systems over the last 30 years. I've been very fortunate to work with many interesting people who are passionate about this technology...engineers, geologists, mechanical contractors, drillers, excavation contractors...in different parts of the world. I've learned a lot from them and will be using this forum to pass on some of the things I've learned and feel are important. Please feel free to use this information if you feel it's worthwhile...hopefully you can avoid some of the same mistakes I've learned from.