The answer is simple! Yes, you can use geothermal technology in most homes. At Hoffmann Brothers Heating and Air Conditioning, we work alongside the GeoComfort team to install geothermal systems in existing homes every week. We even have techniques to work around big obstacles and challenges like small yards and large trees.
My name is Robert Hoffmann, owner of Hoffmann Brothers Heating and Air Conditioning in St. Louis, MO. As a registered professional Mechanical Engineer with over 30 years of experience in the HVAC industry, I have geothermal heating, cooling, and hot water in my home and use it to heat my pool. Seventy-five percent of the energy to heat my home comes from the ground. The heat extracted from the ground is renewable, reduces the carbon footprint of your home, and best of all, heat from the ground is free.
Hoffmann Brothers only installs geothermal systems in existing homes. We install three types of loop fields: lakes, vertical, and horizontal loops. In a city environment, we are almost always installing vertical loops because that is what most homes allow for. We also service and maintain hundreds of systems installed by other contractors, and see great success with vertical loops.
Contractors drill vertical geothermal loops anywhere between 150’ per ton to 200’ per ton. We drill our geothermal systems at 200’ per ton. In our experience, the systems run more efficiently with the extra length and can hold up better in extreme cold or record hot conditions. A typical 4-ton home would require (4) two hundred-foot holes approximately 10’ to 12’ apart.
We subcontract our drilling and have relationships with two different drilling companies. One company has a small rig mounted on a tracked vehicle. The small rig can get in a 5’ wide gate and can maneuver in small spaces and around trees. The other drilling company uses larger drilling rigs that are limited in where they can go. When space is limited our only choice is to use the smaller drilling rig.
Trees are another obstacle in existing homes because sometimes they are large and numerous. Our goal is to preserve trees without damage. When you look at the canopy of a tree you should assume the root system under the ground looks the same. Drilling will not damage trees but when excavating between the holes with a backhoe, a substantial amount of root damage is possible if you are under the canopy of the tree. We use a 12” wide bucket and excavate 4.5’ deep between each hole and up to the house. Our goal is to do all the drilling and excavating outside the canopy of the trees to avoid damage.
We locate our loop field and trench with the intention of avoiding roots. We sometimes run across situations where the only open space to drill is at the rear of the property line but where numerous trees exist between the house and the loop field. In these situations, we will use horizontal boring of headers instead of excavating with a backhoe. Horizontal boring will not damage trees like trenching would. We also use horizontal boring of our header to get under driveways, sidewalks, patios, decks and similar areas.
When a property has no yard or trees cannot be avoided, we drill in the driveway or parking lot. In some cases, we will cut a 12” wide path down the center of the driveway. Our technicians start drilling at the street then keep drilling down the driveway until we reach the house. Sand is placed on top of the pipes, then fills the rest of the 4.5’ deep trench with clean rock and capped with concrete.
Geothermal works in houses of all sizes. We have installed geothermal systems in 20,000 ft2 homes requiring (40) 200’ loops and as small as an 800 ft2 home requiring (2) 200’ loops. Hoffmann Brothers installs geothermal systems for heating pools, heating floors, heating domestic hot water, and can build geothermal dehumidification systems for indoor pools. The possibilities are endless.
Geothermal heating and cooling can be installed no matter the age of the house, size of lot and number of trees. If you live in St. Louis, MO and are ready to look at installing geothermal in your existing home, then we're here to help. Fill out the contact form below, and we'll be in touch soon!