Geothermal HVAC questions, answered (and how to check if you qualify for 50%)

The federal credit adds 10 percentage points for projects in an energy community. There are three ways a site can qualify:

1. Coal closure. The site is in a census tract, or right next to one, where a coal mine closed after 1999 or a coal-fired power plant unit retired after 2009. Check your address on the Department of Energy's Energy Community Tax Credit Bonus map. In the St. Louis area, tracts around Ameren's retired Meramec plant in south St. Louis County and Rush Island plant near Festus qualify.
2. Statistical area. The site is in a metro or rural area with significant fossil-fuel jobs or tax revenue and unemployment at or above the national average. The same map shows these. The St. Louis metro doesn't currently qualify this way.
3. Brownfield. The site is a brownfield: land where reuse is complicated by contamination, including petroleum from an old underground fuel tank. Brownfields are not on the DOE map. Search EPA's Cleanups in My Community map, and check whether the site has a record with the Missouri Department of Natural Resources' brownfields program. A site that has been through an environmental assessment that found contamination may also qualify.

The coal closure and statistical area lists are updated each year by the IRS, most recently in June 2026. The map is a screening tool, not a tax ruling, so confirm with your tax advisor before you count on the bonus. Then plug it into the calculator by checking the energy community box.

Businesses claim it against their federal income tax, or sell it to another taxpayer for cash. Public schools, churches, nonprofits, cities, counties and tribal governments can't use a tax credit, so they choose elective pay and the IRS sends them the amount as a cash payment after the system is in service and they file their annual return. The credit covers the geothermal equipment (the ground loop, heat pumps and related parts), not every line of a project.

It's the rule behind the 10% U.S.-made bonus. Structural steel and iron have to be made in the U.S., and a set share of the manufactured parts has to be U.S.-made too. Meeting it takes the credit from 30% to 40%. It has to be planned at the specification stage, so tell your contractor up front.

For geothermal heat pump systems under Section 48, the base credit depends on when construction begins: 30% through 2032, 26% in 2033, 22% in 2034, and none for projects that start in 2035 or later. The homeowner credit (Section 25D) ended after 2025, so these incentives now apply to commercial, nonprofit and public buildings.

For planning, we estimate a geothermal system at about 44% more than conventional, mostly because of drilling. At a 40% credit, that comes out about 14% below conventional up front, and lower operating costs follow for decades. A test bore and a site survey set the real price. The calculator runs the numbers for your conventional price.

Less than most people expect, because the wells go down, not out. Bores are typically 300 to 500 feet deep and spaced about 15 to 20 feet apart. A parking lot, athletic field or lawn can often hold the whole loop. Where space is tight, a smaller loop paired with a small boiler or cooler (a hybrid system) cuts the drilling.

Yes. The loop is a sealed circuit of high-density polyethylene pipe with heat-fused joints, filled with water or water mixed with a food-grade antifreeze. Nothing is pumped out of or into the ground. Each bore is grouted from bottom to top to protect groundwater, under Missouri Department of Natural Resources rules for heat pump installations. Inside, there's no gas boiler or furnace, which removes an open flame and a source of carbon monoxide.

Yes. A few hundred feet down, the ground here stays in the mid-50s °F all year. In January that's far warmer than the outside air, and in August it's far cooler, so the heat pumps don't work as hard as equipment that trades heat with outdoor air.

Most of the work happens outside. Drill rigs work on a field, lawn or parking lot, and a typical commercial well field takes a few weeks to drill, depending on the number of bores, the rock and how many rigs are on site. The loop is buried and the surface restored. Inside, swapping in heat pumps is like any HVAC replacement: schools usually do it over the summer, and businesses can phase it zone by zone.

The underground loop is sealed and needs essentially none. Indoor heat pumps need routine filter changes and checkups like any HVAC equipment. There are no boilers to inspect and no cooling towers to treat.

Often, yes. One common setup puts a heat pump in each zone. Another uses a central water-to-water heat pump that feeds the building's existing air handlers. A site survey decides which fits.

Yes, and it costs far less now than later. Oversize the main pipes and manifold, run capped pipe stubs toward a planned addition, keep ground reserved for future bores, and drill extra bores while the rig is already on site.

Start with a feasibility review: the building's heating and cooling load, the available ground, a test bore, a cost comparison against conventional replacement, and the credit percentage the site qualifies for. Get an estimate or call 636-327-4238.