This is the single most important task that the homebuyer/homeowner must accomplish to ensure that the end result of going with geothermal results up being a positive, money saving experience. As mentioned previously, most customer complaints about their geothermal system are not the fault of the technology or the equipment per se, but rather how the contractor performed his job, so finding and selecting the best contractor is absolutely crucial.
The best way to find the right geothermal contractor is through word of mouth. If you know of a geothermal equipped home in your neighborhood, ask the homeowner about his/her experience with the system and who they used.
Otherwise the best single source for identifying qualified, experienced geothermal installers is through the International Ground Source Heat Pump Association (IGSHPA pronounced “IG-SPA”). IGSHPA is a national organization affiliated with Oklahoma State University and is the leading training and professional certification organization. It maintains a current list of IGSHPA accredited installers and certified geothermal designers specializing in closed-loop geo systems. An IGSHPA accredited installer is your best bet for selecting the right partner for your geothermal project (www.igshpa.okstate.edu).
Geothermal heat pump manufacturers are also a good source for locating local contractors and should be consulted in your search. These contractors have undergone training on specific manufacturer heat pump offerings. They may like to use one specific heat pump manufacturer over others, but they should have the knowledge and experience to work with more than one manufacturer’s products, depending on the specific needs of any project. (For more on heat pump manufacturers, see the section Geothermal Goes Mainstream).
Your selected contractor will know of local drillers for the ground loop and will recommend them to you. You should aim to use a Licensed Driller. In some cases, geothermal contracting firms have integrated the drilling function into their operations.
Questions to Ask
Here is a list of questions to ask the contractors you engage with in the selection/bid process:
- How long have they been doing geothermal work?
- How many projects have they completed?
- Are they accredited (if they’re not on IGSHPA’s list)
- Can they recommend past customers for you to speak with?
- Do they specialize in residential-scale geothermal installations?
- How do they size the geo system? Do they use ACCA Manual J or ASHRAE methodology?
- Do they use load calculation software to determine the best size heat pump unit for your home and the loop field needed?
- What type of heat pump do they recommend and by which manufacturer?
- Will they give you a written cost appraisal, delivery & warranty for their work?
- Are they knowledgeable about available state and local tax credits and possible utility rebates in addition to the federal tax credit?
- What type of monitoring system do they recommend you have to make sure your geothermal system is working properly?
- Do they offer a service/maintenance contract so they stay with your system in operation?
A good blog resource where you can discuss with other people engaged in the geothermal process and get good answers and feedback is at the National Geographic Energy blog.
Requesting Bids and Undergoing Site Visits
Unless you know of a contractor who has done work that you can verify with a family member, neighbor or friend who has a geothermal system installed by this contractor, you should develop a short list of possible installer candidates who you would be confident to engage further with. This will provide you with a range of prices and suggested approaches in terms of system design and heat pump options.
After completing your initial contacts, at this point you will want to receive bids to complete the work from each of these candidates. However, for them to prepare appropriate bids, site visits to your property will be required. These visits will allow the installer to evaluate your specific property and your home (or your builder’s plan) with you and give you the opportunity to ask all the questions you have prepared and additional questions that will inevitably arise in the course of your time and conversation with the contractor.
Bear in mind that the site visit is the occasion for the geothermal contractor to gain a better understanding of your specific situation and your property’s suitability for a geothermal install. More precise information will be contained in his bid. The Homeowner’s Guide to Geothermal Heat Pump Systems points out that his design strategy may be something he likes to keep to himself for competitive reasons: “In many markets, the design is the installer’s competitive advantage that they have honed over years of experience in conditions specific to your geographic location. The effectiveness of their designs will be evidenced through talking to their references, performance data from their other installations, and a service agreement that shows they will stand by their work.”
The authors of Geothermal HVAC: Green Heating and Cooling add: “good job proposal should leave nothing up to chance or misinterpretation and should spell out the exact equipment to be used. You are spending a lot of money on a new system, whether for a residential or commercial application, and you deserve a detailed roadmap of the process.”
Making the Final Installer Selection
If you solicit several or more bids from accredited installers, your final selection may either be self-evident or a more nuanced decision. In any event, the final decision on who to go with will come down to experience and credentials, the cost of the work and your budget, and what may be most important, your gut feeling about confidence/trust and rapport with the installer. Good luck!