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Geothermal: Loop Field Requirements

The Loop Field milestone confirms that the underground geothermal loop field has been fully installed and verified before moving into indoor equipment installation. It is the first operational milestone. The Loop Field milestone is a two-part submission:

  • Part 1 - Design documents: submitted up front in the Design section of the portal.

  • Part 2 - Loop field package: the install-verification documents, submitted after the loop field is in the ground.

Both parts must be complete before the milestone can be approved. Submit everything through the Palmetto Portal or API.

Supported configurations

  • Loop field: closed-loop only, either vertical bore or horizontal trench

  • Indoor unit: forced-air (ducted)

Not supported in the initial version

  • Pond/lake loops

  • Hydronic/radiant indoor configurations

  • Retrofits and new construction (whole-system installs at existing homes only)

Requirements


1

Manual J Load Calculation

Whole-house heating and cooling load calculation per ACCA Manual J, room-by-room.

  • Produced in ACCA-approved software (Wrightsoft, Elite RHVAC, or CoolCalc)

  • Block load and room-by-room loads included

  • Design conditions match project ZIP code (ACCA Table 1A)

  • Building inputs documented: orientation, insulation, windows, infiltration

2

Manual S Equipment Selection

Heat pump selection report demonstrating capacity match to Manual J loads at design conditions.

  • Selected heat pump model and AHRI certificate referenced

  • Total and sensible cooling capacity at design EWT vs. Manual J cooling load

  • Heating capacity at design EWT vs. Manual J heating load

  • Cooling oversizing within ACCA limits (≤115% total, humid climates per Manual S)

  • Auxiliary / backup heat sized and documented (required for Northeast projects)

3

Ground Loop Design Report

Loop sizing and configuration from an accepted geothermal design tool.

  • Produced in an accepted tool (see list below)

  • Loop type, total bore footage, borehole count, and depth specified

  • Design EWT/LWT, flow rate, and antifreeze solution documented

  • Ground thermal conductivity value used and source cited

  • Grout thermal conductivity and pipe specification (HDPE 3608 / 4710 / PEX-A) listed

  • Rule-of-thumb sizing (e.g., feet per ton) is NOT acceptable

How to submit the Design Documents

1. Scroll down in the customers page, and click in the + Loop Field Package button:

2. Upload all Design Documents

  • Load calculation and equipment selection (Manual J & S)

  • Ground Loop Design Report

3. After submission, our team will review the initial documents:

Submitted after the loop field is installed. Provide all of the following:

1

Permit

Approved permit, with the permit submitted date and approved date. The permit must be approved before the Loop Field milestone can be completed.

2

Pressure test results

Documentation of the loop pressure test.

3

Loop field photos

Clear installation photos (see the shot list below).

  • Trenches or boreholes before backfill

  • Pipe placement and fusion joints

  • Headers and manifold connections (show the manifold inside the header pit)

  • Grouting setup and completion

4

Drilling invoice

Invoice from the driller for the loop field work.

5

Bore log / as-built

The as-built bore log showing actual bore depths and configuration.

6

Driller information

Driller name and license.

How to submit the Loop Field package

  • Permit Approved

    • Permit Submitted Date / Approved Date

​

  • Driller Information

    • Driller Name

    • Driller License

​

  • Pressure Test Results

  • Loop Field Photos
    Provide clear installation photos showing:

    • Trenches or boreholes before backfill

    • Pipe placement and fusion joints

    • Headers and manifold connections

    • Grouting setup and completion

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