Will geothermal work for me and my particular building?

While a professional certified geothermal consultant will need to be consulted about your particular circumstances, here are some general factors that you will need to consider.

Can I afford the initial investment?

Average costs for a ground source heat pump for a residence can range between $18,000 - $30,000, which is approximately three times the price of a conventional system. However, this will be one system that will both heat and cool your house, instead of having to purchase separate furnace and air conditioning units.

You might be able to receive significant subsidies and/or tax credits from your county, state and/or federal government. However, it may take a year or more for all tax rebates or grants to be received. In addition you may be able to get a low cost loan by refinancing your house. It may even be possible to get some sort of special low interest loan (or “green energy loan”). Some companies that do the installation will also offer financing as well.

Do I have enough land available?

You will need a minimum 15 by 15 foot (4.572 by 4.572 meters) area for a vertical installation and more for other types. Also, some drilling rigs are the same size as an 18-wheel tractor trailer, so allow approximately another 12 by 30 feet (3.66 by 9.1 meters) for the vehicle itself. The back end of the drilling rig will need to be positioned where the holes will go. The rig will need to move to a vertical position, so no power lines or tree branches can be in the way. Different kinds of rigs are featured in the slide show.

Is this house new construction?

If yes, then ABSOLUTELY go with a ground source heat pump. There will never be a cheaper or easier time for installation. Often the upfront cost can be included with the mortgage loan.

Will this be an “easy install”?

If your particular circumstances are less complicated costs will be lower. The pipes will need to go from the wells, into the house and to the unit. A short easy run for those pipes will keep costs down.

Am I willing to have a place for the tubing to come into my house?

If yes, think carefully, because at some point the tubing will need to come up from the ground, go into the house (through a wall) and to the heat pump unit. This slide show demonstrates how the pipes were brought into the garage of the homeowners featured in the case study later in this website.

Do I live in a warm climate?

If yes, your energy savings will be maximized since ground heat pumps are most effective when air conditioning.

Do I have an alternative for winter heating?

If yes, then ground heat pumps will make more sense for you. A gas furnace or wood/pellet stove will minimize your winter heating cost even more.

Do I mind having my yard ripped up?

You may very well have to sacrifice some of your existing landscaping. Drilling, excavating and trenching will make a mess and may damage grass, flower beds, trees, walkways, patios, and/or walls. It may also interfere with any French drains. It is possible that the installer could bring in special boring equipment to tunnel underneath instead. However this will incur additional cost.

The drilling rig will leave big ruts in the yard and may damage any driveways or walkways it goes over. However, if you aren’t happy with the way your yard currently is landscaped, a geothermal installation might be a good opportunity to start fresh and create a new look.

Are you willing to deal with the excavated soil and rocks?

The soil and bedrock that is displaced from the digging will need a place to go during construction. The dirt removed from the trench can be placed back in the trench once the pipe installation is complete. Dirt can also be incorporated into landscaping by creating berms of soil for flower beds.

The debris that comes up from drilling vertical wells will be a wet slurry-like mixture of very small pieces of the underlying bedrock. The water from this mixture should ideally stay on the site or go into a stormwater management area. This will probably work well if the site is level and large enough. However, something called a “silt bag” may need to be used. It will capture the silt and prevent it from running into the storm drain (and therefore into local waterways) with the excess water. Silt bags cost approximately $450 USD per bag. The silt bag can be placed directly in a dumpster and removed from the site.

Another way to prevent run-off from contaminating a local waterway would be use of a silt fence, which would allow water to seep through the fence while capturing dirt and debris. Silt fences are commonly used at construction sites to prevent soil erosion and run-off and are required in many jurisdictions. On steep hills or with very heavy debris loads, a metal chain-link fence is installed behind the silt fence in order to prevent collapse or overload.

Is the area you are thinking about for installing your system on a hill?

It is certainly possible to install on a hill, but this may add complications and expense. It may be possible to grade the land ahead of time, or it may be easier to choose another location. You may also have to take additional measures to manage water run-off.