Reading Your Results
The assessment gives you numbers and it tells you how much to trust them. The second part matters as much as the first.
The confidence badge
Every assessment carries a badge beside the site coordinates: High confidence, Medium confidence, or Low confidence. This is the trust signal, and it is the thing to read first.
On a low-confidence result the page also shows a red banner, Low-confidence estimate - verify before design use, with the percentage of your bore depth the estimate actually covers. Treat that banner as a stop sign, not a footnote.
The property tiles, and the units
The headline properties are shown in IP units with the SI value directly beneath them. Thermal conductivity, for example, reads 1.431 Btu/hr·ft·°F with 2.48 W/m·K underneath.
That matters when you move to a ground-loop design, because the design wizard asks for conductivity in W/m·K. Read the W/m·K number off the tile and type that. Do not convert by hand: the number you need is already on the screen, and the per-layer table and the PDF export carry both units as well.
The conductivity band
The estimate is a range, not a single figure, and the range is shown with the tile.
What makes the band wide is the rock, not the number of logs. It starts from the published conductivity spread for each formation in the hole, then widens for three things: logs that disagree with each other, dry (unsaturated) intervals, and depth extrapolated past the deepest control log. Well count does not enter it - that feeds the confidence badge instead.
So a well-logged site in a formation with a naturally wide literature spread can carry a wide band, and a site with only a couple of logs through uniform limestone can carry a narrow one. Read the band and the badge together; they answer different questions.
Design against the low-conductivity end of the band, not the middle. Low conductivity means the ground carries heat away more slowly, and that is the case that sizes the loop field.
On-site TRT recommended
This callout appears above the results when the estimate is not solid enough to design against on its own. Its wording is direct: these are literature-based estimates, not a measured thermal-response test, and an on-site TRT would narrow the conductivity range and firm up loop-field sizing.
It fires on any one of several conditions, not only a wide band:
- no usable log coverage at the site
- a wide band relative to the estimate
- a large share of the bore depth extrapolated below the deepest control log
- nearby logs that disagree with each other
- signs of moving groundwater, meaning a high median yield in nearby wells through a saturated column
That last one is worth knowing, because it can fire on an otherwise tidy-looking estimate. Flowing groundwater carries heat away in a way a static-conduction model does not capture, and no amount of good log coverage tells you about it.
The estimate basis card
Estimate basis is not a trust rating. It is the provenance breakdown - what the estimate was actually built from, so you can judge it yourself:
- Nearby wells analyzed
- Control wells (lithology) - how many carried real formation detail
- Extrapolated below control - the share of your bore depth sitting below the deepest log, and therefore inferred rather than observed
- Static water level
- Est. residential depth
- Typical drilling method
Extrapolated below control is the row worth checking. At 0% none of the modeled depth sits below the deepest control log; at 40% you are designing against inferred rock for nearly half the depth. Log coverage is a separate figure - the Lithology coverage stat, and the number the low-confidence banner quotes. Some rows appear only when the data supports them.
Water matters here too. Saturated formations move heat considerably better than dry ones, so a site drier than typical for the area reads high and a wetter one reads low.
The per-layer table
Underneath the tiles is the formation-by-formation breakdown: each depth interval, its lithology, whether it is saturated, and its conductivity in both units. Sanity check it against what you know locally. If it shows thick saturated sand where you have only ever drilled clay, trust your own experience and treat the estimate as suspect.
It also shows where the drilling changes. A shift from unconsolidated clay to consolidated limestone at a given depth is the point your rig changes method, and the narrative calls that out.
Depth sensitivity
This card answers the question you are actually asking: how deep is worth drilling here.
At the top is a green recommendation callout naming the depth it suggests, and a Re-run at N ft button that re-runs the assessment at that depth in one click, so you do not have to retype the location.
Below it is a table comparing candidate depths, each with its effective conductivity, its range, and the ground temperature at that depth. A Best badge marks the one being recommended. Read down the conductivity column: the point where it stops climbing meaningfully is the point where extra footage stops paying for itself. Going deeper is not wrong; it is a decreasing return, and the table lets you price that tradeoff instead of guessing at it.
The card also carries a note when the drilling method changes with depth, which is where a deeper option stops being simply more of the same hole. The narrative explains the same choice in prose if you would rather read it than read the table.
When you have logged a test nearby
If a thermal-conductivity test of yours sits near the site, a green card appears above the results reading On-site TC test nearby, listing the test, its distance, its date, and its conductivity. With more than one in range the heading becomes N on-site TC tests nearby and it lists up to three. A test logged without a date shows No date, which is normal - the date is optional.
Read the second line, because the card has two states:
- Already calibrating this estimate means the test is anchoring the numbers. You will also see an Anchored by on-site TC test chip with the distance.
- Without that line, the test is merely nearby: close enough to tell you about, not close enough to be pulling the estimate toward it.
Anchoring does not automatically clear the TRT-recommended callout. An anchored estimate can still be flagged, and when both appear together the flag is telling you something the anchor does not answer.
Aquifer flow
The aquifer section is separate from the ground-property estimate, and it is the part that matters for open-loop work. Its yield figures are reported in gpm, with 25th and 75th percentile values. Those percentiles describe expected water yield. They are not the conductivity band, and the two should not be read together.
Related Topics
- Running an Assessment - produce the results
- Thermal-Conductivity Tests - anchor an estimate to a real measurement
- Ground-Loop Designs - size the loop field