The Project


Frequently Asked Questions

In reading this FAQ, it is important to remember that each job, and each contractor, is unique. Our experiences will most likely be different than yours.

About Cost & Comfort

How comfortable is the system compared to a regular furnace?

We've found the geoexchange system to be more comfortable than our old gas furnace. The big difference is the heating is more even. We had some very hot/cold areas before but the heat is now distributed better. Our basement is still much cooler in the summer; however, I think that may be the nature of basements.

For the most part I don't really think about it any more. Our system, and probably most others, has an electric coil to use as auxiliary heat. From what I understand, this can be used when you want to heat the house very quickly. We turned ours off since it is much less efficient than the geoexchange heat pump. I've not noticed any instance where it was needed. Since we program our thermostat everything works seamlessly.

How much does it cost?

Feedback from visitors to this site suggests that prices vary widely across the country. Take a look at our Costs and Benefits section for more information.

Are there any federal or state incentives?

There are incentives to help pay for geoexchange systems but they are not as large as for solar (yet). In Maryland there are grants available for up to $3,000 (based on size of the system—ours is average and qualifies for the entire sum). Federal incentives are fairly minor at this point ($300). Check out the Geothermal Heat Pump Consortium website for detailed and up-to-date information. It is also helpful to call or visit the website of the Department of Energy for your state.

How do I find a contractor?

We found ours through the International Ground Source Heat Pump Association. Read our section on contractors for some ideas how to choose a contractor.

About the Geoexhange Heat Pump Installation

The actual geothermal heat pump installation is pretty much the same as installing a regular heat pump. The main difference is the addition of tubing to carry the water through the ground loop. Take a look at our Installing the Heat Pump section for more detailed information.

Can it be installed in winter?

Time of year doesn't really matter. Having a geothermal system installed in winter isn't a problem.

What happens if the water in the geothermal ground loop freezes?

An antifreeze (in our case methanol) is added to the water in the pipes to prevent freezing. And remember, after you go down a little ways in the ground the temperature is stable year-round (around 55 degrees for us).

What if the ground loop tubes leak?

That would be a problem, depending where they leaked. From what I understand this is highly unlikely since they are tested at high pressures to make sure no leaks exist. The ground loop tubing in our system is guaranteed for 50 years.

About Drilling

What about shrubs, small trees, and plants?

You may have to move them for two reasons. One is to allow access for the drilling rig, which is rather large. The second is for the trenching that is needed to bring the geothermal ground loop tubing into the house. We had to move a small tree to give the drilling rig access to the yard. We also had to remove one shrub and prune another in the area where the tubing entered the house.

We were told that planting trees in the area later would not be a problem. It's a good idea to document exactly where the wells and tubing are located, for future reference.

How will they decide where to drill?

It's all about access and a flat place. Trees, hills, power lines, water mains, sewage lines, gas lines, and any obstructions will also factor into the drilling location. We were very limited and ended up drilling right in front of our house.

What if they hit rock?

In our contract there is a clause that we pay more if they hit rock or if they need to put a special casing all the way down due to unstable, muddy layers.

What if they hit water?

They don't seem to like to hit water although they did on our wells at about 100 feet down. The well then filled up with water while they were drilling. This made things more of a mess but didn't seem to slow the drilling any. On the second day of drilling, they brought a special truck to capture the water and mess. The well was sealed and capped so there isn't a fountain in the yard. They also took care to prevent any groundwater contamination.

What if they hit magma?

Let's hope they don't drill that deep.

How noisy will it be?

I suppose it varies. The cats certainly weren't very amused but they seemed to get used to it after a while.

How long will it take?

The total operation took four days. It took our contractor one day for each well (each well was 300 feet deep). They hit rock at 20 feet down, which makes the drilling slower. Much of it depends on the contractor, their equipment, and what they hit. There was a half-day spent capping the wells, and another full day digging the trench and bringing the lines into the house. Your mileage may vary.

If you have any questions or comments feel free to drop us an e-mail.