What Happens on Geothermal Installation Day?
It is not one day. A geothermal install runs in stages: site survey and design first, then ground work where the loop goes in, then the equipment and duct connections, then commissioning. Most of the noise and mess belongs to the ground day.
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People picture a truck showing up and a system appearing by dinner. That is a furnace changeout. Geothermal has a second half that happens in your yard, and knowing the order takes most of the anxiety out of it.
Every stage, in order
- Site survey
I come look at the house and the property together. Where can a loop physically go, what can the duct system carry, what does the electrical service look like, and where does the equipment live. Nothing gets designed off a phone call.
- Manual J load calculation
A room-by-room heat gain and loss calculation that tells us what your house actually demands. Geothermal gets sized to that number, not to whatever is sitting in the closet now. Guessing the size on a geothermal system is expensive twice, once in equipment and again in loop.
- Loop design
Loop length follows from the load and the ground. More tons means more pipe. Soil type and moisture change how much heat the ground will actually accept, so two houses of the same square footage can need different loop fields. This is also where horizontal versus vertical versus pond gets settled.
- Ground day
The loud one. Either a trencher opening horizontal runs across the yard, or a drill rig putting in vertical bores. There is equipment on your property, there are cuttings or spoil, and the yard is disturbed. This is the stage worth planning around.
- Grouting and sealing
On vertical bores, once the pipe is in, the hole is sealed with grout. Two jobs at once: it protects groundwater by sealing the bore, and it makes solid thermal contact between the pipe and the earth so the loop actually performs. A bad grout job is invisible from the surface and permanent.
- Pressure test, purge, and flush
The loop gets fused rather than glued, pressure tested, then purged and flushed to drive the air out. Air trapped in a loop is a performance problem that looks like a hundred other problems, so it gets chased out before the system ever runs.
- Equipment and ductwork
The indoor unit, the flow center, and the connections go in. If the duct system needs modification, plenum work, or a fix for undersized returns, this is where it happens. It should never be a surprise at this stage, because I checked it during the survey.
- Commissioning
The proving step. Loop pressure and flow, refrigerant charge, temperature split across the coil, control setup, and airflow, measured and written down. A geothermal system that was never commissioned is a system nobody has proven.
What ground day actually looks like
If the loop is horizontal, a trencher cuts runs across the yard and the pipe is laid in and backfilled. You get long lines of disturbed ground where the trenches ran.
If the loop is vertical, a drill rig sets up and puts bores straight down. The rig needs access, which means a path wide enough to get it in and a spot to work from. Vertical uses far less of your yard but the working area around the rig takes a beating.
Either way, the ground is disturbed, it looks rough for a while, and it settles over a season. I go through this in detail on will geothermal tear up my yard, because it is the objection I hear more than any other and it deserves a straight answer instead of a brochure photo.
The questions that separate a good install from a bad one
Can I see the load calculation? If nobody ran a Manual J, the system size is a guess, and on geothermal a guess is buried in your yard.
What are the commissioning numbers? Flow, loop pressure, and the temperature difference across the heat exchanger tell you whether the loop is performing. Ask for them in writing at the end of the job. Ask me. Ask anybody.
What happens to the duct system? Geothermal moves more air at a lower temperature than a furnace does. Marginal ducts get exposed. A contractor who never mentions your ducts has not looked at them.
When a geothermal system disappoints somebody, it is almost always one of three things: sized wrong, loop undersized, or the duct system was never addressed. All three are install problems, not technology problems, and all three are visible in the numbers if anyone bothered to take them.
Installation questions I get asked most
How long does a geothermal installation take?
It runs in stages rather than a single day: ground work, then equipment, then commissioning. The schedule is usually driven by the loop crew and the weather rather than by the equipment side. When I quote your job I give you the real calendar for your property, not a generic range.
Can I stay in the house during the installation?
Yes. There is a stretch with no heating or cooling while the old system comes out and the new one goes in, and that is the part worth planning around if we are in the middle of July or January.
Do I need new ductwork for geothermal?
Sometimes. Geothermal moves a larger volume of cooler air than a furnace, so undersized or leaky ducts that were tolerable before will hurt performance here. I check the duct system during the survey and tell you straight if it needs work.
What if there is rock under my property?
Then the loop plan changes and so does the price. Finding that out at the survey is far better than finding it out mid-bore, which is one of the reasons a geothermal quote requires me to come look.
Will my water well or septic system be in the way?
They have to be located and worked around, which is exactly what the site survey is for. Existing wells, septic fields, buried utility lines, and easements all shape where a loop can go.
Can geothermal be installed in an existing house or only new construction?
Retrofit is most of what I do. New construction is easier because the loop goes in before the landscaping exists, but an existing home with usable ground or drilling access is a normal job.
What do I get at the end of the job?
Commissioning numbers, equipment documentation and warranty registration, and the record of what went in the ground. Keep the loop layout with your house papers. The next person who works on it will need it.
Start with the survey, not the quote
I walk the property, look at the ducts, and tell you what your house actually needs before anybody talks price. Estimates on a new system are free.
New system estimates are free. Geothermal is statewide across Oklahoma, not just my seven daily service counties.