Geothermal System Design: Selecting Your Design Team
The common start for any geothermal heat pump system is exactly like the heating/cooling that’s been planned for any building you can name. The thermal loads must be known in advance. Any decision to increase a building’s conditioned space or significantly alter its glazing or construction materials requires a re-calculation of its thermal loads or else comfort and efficiency may both suffer. Your building designer, engineer or HVAC contractor will use an approved calculation method to estimate building thermal loads in your climate and on your specific site. This is true (and appropriate) from the smallest residence to the largest commercial building.
You’re looking for a design/installation team with a successful track record in designing systems to serve various buildings. Unless you can gain access to all the performance data and the energy bills of the candidate’s previous work, the quickest route to evaluation (in addition to a one-on-one interview) is references to previous satisfied customers. This is a best-practice for any kind of construction or installation work, and is expected by the professionals you will seek out.
Your choice will be made on your own weighting of your candidate’s communication skills, a full explanation of how your project would proceed, full disclosure of quality control measures and your recourse if not satisfied, with written guarantees for warranty and/or call back. This is not unlike an audition, and all the time you take to prepare a checklist, a series of questions, or a matrix template of your needs will be time well-spent in advance. You may find that competent professionals will respect such organization, in fact, they will welcome it. It means that even if not on the same page, you’re at least working from the same book. Any appropriately planned job should be accompanied by a contract, licensing verifications, a recission clause, and a sizable payment holdback until 30-days after commissioning is complete.
Geothermal heat pumps are a mature technology, but the practitioners who specialize in it are still growing in number. Cautious preparation (just as in all successful project completion) will help insure you receive the quality job that we all have a right to expect. If some of this preparation on your part seems daunting, just remember—you’re closing in on the heating and cooling with the lowest life cycle cost your building could incorporate. As a renewable, the fuel is always free.