Thermal Conductivity Test Results Test Hole A1,...

Major Geothermal 6285 West 48th Avenue, Wheat Ridge, Colorado 80033 – 303 / 424-1622 voice, 303 / 423-6795 fax

Toll free - 800 / 707-9479 www.majorgeothermal.com

Thermal Conductivity Test Results Test Hole A1, 400’

Ellicott Middle School Ellicott School District 22

350 South Ellicott Highway Ellicott CO 80808

December 20, 2012

Client:

Mr. Chris Guarino Consilium Partners, llc

1738 Wynkoop St., Ste. 302 Denver, CO 80202

(970) 471-1509 (303) 539-9840 fax

[email protected]


Toll free - 800 / 707-9479 www.majorgeothermal.com Page 1 of 4

December 20, 2012

Thermal Conductivity Test Results

Ellicott Middle School Ellicott School District 22 350 South Ellicott Highway, Ellicott CO 80808

Summary

The results of the thermal conductivity test are summarized as follows:

Thermal conductivity 1.11 btuh/ft/°FDiffusivity (weighted average) 0.68 ft²/dayUndisturbed temperature 56.3 °FBorehole thermal resistance 0.19 hour/ft/°F/btu

Grout, blended to 30% solids (DWR regulations) 0.90 btuh/ft/°FPipe size 1.25” DR11 HDPENominal bore diameter (bit diameter) 5.25” Nominal bore depth, below grade 400’ U-bend assembly, installed depth below grade 408’Average power input 7974.7 wattsWatts per foot 19.9 wattsFlow rate average 7.99 gpmDate drilled/loaded/grouted December 12, 2012Net hours to drill to TD 3.5 hoursNet hours to load loop 0.5 hoursNet hours to grout 2.0 hoursTotal time, drill start to loop install completion 6.0 hoursTest date – data logging* December 18-20, 2012

Values in bold are critical inputs for closed loop ground heat exchanger design. Test duration, 48.0 hours gross. Power input validated to within ASHRAE tolerances. Calculation interval, 15 to 44 hours, optimum calculation confidence. First 12+ hours, thermal saturation of borehole. Confidence in measured TC value: high. Note: 6.0 hours net time to drill, install the ground loop and grouting of the test hole to surface. This suggests a high production completion rate for ground heat exchanger construction of at least two and possibly three boreholes per day per drill rig.



Drill log, borehole A1:

Footage Net Lithology Description

Start End 0 60 60 Tan sandy gravel

60 75 15 Tan gravel, 1/2 - 1/4 in size 75 185 110 Tan sand & gravel

185 305 120 Blue shale w/ sandstone layers 305 408 103 Light blue sandy clay

0 60 60 Tan sandy gravel

408 Total depth drilled from grade

408 U‐bend installation depth from grade

Log provided by Can American Drilling, Simla, CO. Test Hole Location



Test Hole Location (Perspective)

Project Location – Ellicott, CO

Approximate area for installation of the ground heat exchanger



Slope: 4.86Calculation Interval: 15.0 to 44.0 hours

* * * * * Please call us should you have any questions.

Terry Proffer, CGD

Major Geothermal

Geologist IGSHPA Accredited Installer #12131-994 IGSHPA/NATE Certified Installation Instructor #T1063-496 AEE Certified GeoExchange Designer #16 AEE/IGSHPA Certified GeoExchange Design Trainer Colorado Division of Water Resources Closed Loop Certification #GT-13 ClimateMaster Certified Installation Instructor EllicottMidSchl_TC_Report_2012-12-20.docx

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Ellicott Middle School TC Test Power vs. Time

Ellicott Schl Dist 22_TCTest_Graphs_2012‐12‐20.xlsx

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Ellicott Schl Dist 22_TCTest_Graphs_2012‐12‐20.xlsxEllicott Schl Dist 22_TCTest_Graphs_2012‐12‐20.xlsx

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Ellicott Middle School TC Test Delta T vs. Time


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Drill log provided by:

MAJOR GEOTHERMAL

www.majorgeothermal.com

Can ‐ America Driling, Inc.

708 Cheyenne Ave ~ PO Box 416 Simla CO 80835

TEST BORE DRILL LOG ‐FORMATION DESCRIPTIONS & NET SECTION THICKNESS

Ellicott School District 22 ‐ TC Test Hole A1

canamericadrilling.com

708 Cheyenne Ave ~ PO Box 416, Simla, CO 80835

719‐541‐2967 ~ Fax 719‐541‐9545

Start End

0 60 60

FootageNet

Inputs in yellow cells are manual entries. Light blue cells are calculated from entries.

Lithology Description

Tan sandy gravel

350 South Ellicott Highway, Ellicott CO 80808

0 60 60

60 75 15

75 185 110

185 305 120

305 408 103

0

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Light blue sandy clay

Tan sand & gravel

Tan gravel, 1/2 ‐ 1/4 in size

Blue shale w/ sandstone layers

Tan sandy gravel

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408 U‐bend installation depth from grade

Total depth drilled from grade

Form No. GX-01 1/2006

GEOEXCHANGE LOOP FIELD CONSTRUCTION AND TEST REPORT

STATE OF COLORADO OFFICE OF THE STATE ENGINEER

1313 Sherman St. Rm. 818 Denver CO 80203 Phone - info: (303) 866-3587 Main: (303) 866-3581 Fax: (303) 866-2223 http://www.water.state.co.us

For Office Use Only

1. PERMIT NUMBER: 74 -GX 2. OWNER NAME(S):

Ellicott School District 22 MAILING ADDRESS: 350 South Ellicott Highway

Ellicott CO 80808 CITY: STATE ZIP

PHONE: ( ) - Div WD Basin MD

3. PROPERTY LOCATION: County: El Paso Parcel ID Number (Optional):

350 South Ellicott Highway Ellicott CO 80808(STREET ADDRESS AT LOOP FIELD LOCATION) (City ) (State) (Zip)

1/4 of the 1/4, Sec. , Township N. or S., Range E. or W., P.M.

SUBDIVISION NAME: , LOT , BLOCK , FILING/UNIT

4. LOOP FIELD POINT OF ORIGIN: DISTANCE FROM SECTION LINES: Ft. N. or S. Line, Ft. E. or W. Line.

Optional: GPS well location information in UTM format. The following GPS settings are required: Format must be UTM. Units must be in meters. Datum must be NAD83. Unit must be set to true north. Zone 12 or Zone 13 Was GPS unit checked for above items? YES NO

Easting 553100

Northing 4297617

5. LOOP MATERIAL: HDPE 3408 DIAMETER: 1.25" 6. DATE COMPLETED: 12/12/2012

7. CIRCULATING FLUID (include mixture percent): Potable Water 8. FIELD TYPE: POND LOOPS

HORIZONTAL (Trench) VERTICAL DIRECTIONAL

9. DEPTH OF LOOPS: 402 ft.

10. TRENCH INFORMATION: 12. HOLE DIAMETER: 5 1/8 in.

Average Depth: ft. NUMBER OF HOLES: 1

Average Width: ft. 13. GROUT: Cetco High TC Thermal Grout

Excavated with Type and amount of each material (INCLUDE WATER):

11. BACKFILL MATERIALS: 900 lbs grout per hole

3600 lbs grout per hole

306 gallons water per hole

14. TEST DATA:

Prior to installation: After Installation:

Design/Test Pressure (psi): 110 Test Pressure (psi): TC

Test Length (hrs): 3 Test Length (hrs): TC

Date/Time Measured: 12/12/2012 Date/Time Measured: TC

15. NAME OF CERTIFIED INDIVIDUAL (type or print): Adam Grotticelli

Mailing Address: Can-America Drilling, Inc.

PO Box 416 Simla, CO 80835

Certification No. GT-89 Phone Number: 719-541-2967

The Division of Water Resources’ Online Mapping tool was used to identify rights located within ½ mile. YES NO I have read the statements made herein and know the contents thereof, and that they are true to my knowledge. [Pursuant to Section 24-4-104(13)(a), C.R.S., the making of false statements herein constitutes perjury in the second degree and is punishable as a class 1 misdemeanor.]

Signature: Date:

Form No. GX-01 (1/2006) COLORADO DIVISION OF WATER RESOURCES

DEPARTMENT OF NATURAL RESOURCES INSTRUCTIONS FOR GEOEXCHANGE LOOP FIELD CONSTRUCTION AND TEST REPORT FORM

The report must be typed or printed in BLACK OR BLUE INK. All changes on the form must be initialed and dated. Attach additional sheets if more space is required. Each additional sheet must be identified at the top by the well owner’s name, the permit number, form name/number and a sequential page number. Incomplete forms will be returned for completion. This form may be reproduced by photocopy methods, or by computer. GENERAL INSTRUCTIONS: (numbers correspond with those on the front of this form)

1. Print the loop field(s) number in the space provided at the top of the form. 2. Print the Owner’s Name and indicate the mailing address and phone number.

3. Complete the well location information of where the loop field(s) was drilled. Complete the parcel I.D. number if known. The loop

field(s) location must include the ¼, ¼, Section, Township, Range, Principal Meridian, and distances from section lines. If the loop field(s) is located in subdivisions the lot, block, and subdivision information must also be provided.

4. Complete the loop field(s) point of origin by providing the distances from section lines. An option to providing distances from section

lines is to provide an accurate GPS location in GPS format. The required GPS unit settings must be as indicated on this form. Colorado contains two (2) UTM zones. Zone 13 covers most of Colorado. The boundary between Zone 12 and Zone 13 is the 108th Meridian (longitude). West of the 108th Meridian is UTM Zone 12 and east of the 108th Meridian is UTM Zone 13. The 108th Meridian is approximately 57 miles east of the Colorado-Utah state line. On most GPS units, the UTM zone is given as part of the Easting measurement, e.g. 12T0123456. Check the appropriate box for the zone.

5. Complete the type of material that the loop field(s) is made from. Also include the diameter of the tubing.

6. Enter the date that the loop field(s) was completed.

7. Enter the type of circulating fluid that is in the loops. Include the percentages of mixtures.

8. Indicate the type of loops that were installed

9. Indicate the depth that the loops were installed at.

10. Enter the average depth and width of the trenches that were dug when the loop field(s)s were installed. Indicate the equipment that

was used to excavate the trenches.

11. List the materials used to backfill the trenches.

12. Enter the hole diameter and the number of holes.

13. Enter the type and amount of grout used. You must include the amount of water used in the mix.

14. Enter the test pressure, length of test, and date/time of the test of the loop field(s) prior to installation. Enter the test pressure, length of test, and date/time of the test of the loop field(s) after it was installed.

15. Enter the name, mailing address, and phone number of the person who is certified to install this loop field(s). Enter the individual’s

certification number. Indicate if the Division of Water Resources’ Online Mapping Tool was used to identify water rights within ½ mile of the loop field(s). The report must be signed by the certified individual responsible for the construction of the loop field(s). Submit completed report to: State of Colorado, Office of the State Engineer, 818 Centennial Bldg., 1313 Sherman St., Denver, CO 80203 If you have questions, contact the Denver or the Division Office where your loop field(s) are located.

Division 1 810 9th St., Ste. 200 Greeley, CO 80631 (970) 352-8712 Fax (970) 392-1816

Division 2 310 E. Abriendo Ave., Ste. B Pueblo, CO 81004 (719) 542-3368 Fax (719) 544-0800

Division 3 301 Murphy Drive Alamosa, CO 81101 (719) 589-6683 Fax (719) 589-6685

Division 4 1871 East Main St. Montrose, CO 81401 (970) 249-6622 Fax (970) 249-8728

Division 5 Direct mail to Box 396 Glenwood Spgs CO 81602 50633 U.S. Hwy 6 & 24 Glenwood Spgs., CO 81601 (970) 945-5665 Fax (970) 945-8741

Division 6 Direct mail to Box 773450 505 Anglers Dr. Suite 101 Steamboat Spgs, CO 80477 (970) 879-0272 Fax (970) 879-1070

Division 7 701 Camino Del Rio, Ste. 205 Durango, CO 81301 (970) 247-1845 Fax (970) 259-0944

Denver Office 1313 Sherman St., Rm. 818 Denver, CO 80203 (303) 866-3587 Fax (303) 866-2223



This narrative modified from an article by David Henrich, Dan Bernstein and Barry Peterson, www.groundloopdesign.com. Thermal Conductivity Test Overview The thermal conductivity, or thermal response, test is a way to determine ground thermal properties that are critical for ground source heat pump system design. The test is performed by injecting a known and constant amount of heat (energy) into a borehole heat exchanger and then measuring the temperature response. A competent test can provide the undisturbed formation ground temperature, the calculated thermal conductivity, the calculated borehole thermal resistance and an estimate of the thermal diffusivity. These values, critical for the optimal design of a geothermal system, are integrated into a professional ground heat exchanger modeling software program to determine an optimized closed loop heat exchanger that services the projects building loads and is compatible with the intended heat pump schedule. The engineer using this data must have sufficient comprehension of closed loop GSHP design procedures to account for pipe type and size, grout thermal enhancement (if necessary), headering schedule, circulation pumping requirements accounting for final field pressure drop, minimum air purging requirements, minimum fluid turbulence under peak load for heat transfer and other considerations. The selection of thermal conductivity testing parameters, including hole depth, pipe size and a test hole location that is compatible with the final design, should be selected by an experienced designer after considering annual loads, heat pump schedule and site specifics. Selecting a 400’ borehole depth for testing may have a vastly different value than a 300’ hole at the same location for example. As the test borehole may be incorporated into the final ground heat exchanger configuration, proper site placement is critical. Undisturbed Ground Temperature Determination The undisturbed ground temperature is the constant temperature of the formation, averaged over the length of the borehole, as this is the actual temperature the closed loop heat exchanger will work against for heat extraction and rejection. Typically, this temperature is measured before starting the active thermal conductivity test. The TC module may be allowed to automatically estimate this value from the first few temperature measurements collected via the TC test unit data logger; the engineer reviewing the raw data may also select the temperature average due to site or testing variations for accuracy. If the TC test is initiated too soon after the installation of the test bore, the undisturbed ground temperature may be inaccurate. As per ASHRAE standards, it is recommended that the test borehole rest for a minimum 5 days after installing the borehole before initiating the test so as to ensure that the ground has returned to its native and undisturbed temperature state.



Thermal Conductivity Calculation Because thermal conductivity cannot be measured directly at individual intervals over the length of the borehole, a vertical TC test uses the line source heat transfer model to calculate the required results. The line source model, which assumes an infinitely thin heat source in a homogeneous medium, is very broadly-referenced in the published literature and is considered to be the standard analysis methodology. To analyze test data, the average temperature of the water entering and exiting the heat exchanger is plotted versus the natural log of time. Using regression analysis, a best-fit line is plotted to match the empirical data and the slope of the line is used to calculate the thermal conductivity of the formation. Typically, the data analysis procedure may be repeated several times for several different time intervals to ensure the closest fit between the empirical data and the derived best-fit line. The first 8 to 12 hours of temperature data for most tests are not included in the analysis as this is the period of time usually required to warm the borehole to a constant state. This assures that the conductivity value is determined from steady state rather than transient heat conduction processes. For some tests, this warm up period may be less or greater depending upon conditions. Borehole Thermal Resistance Calculation The borehole thermal resistance cannot be measured directly but can be calculated from the recorded in-situ measurements. After determining the thermal conductivity, the resultant value can be used in the line-source equation to calculate the borehole thermal resistance. Note that the calculated borehole thermal resistance is representative of the entire test bore configuration including the pipe type, pipe spacing, grout resistance and borehole diameter, etc. The empirically derived borehole thermal resistance may be entered into a commercial design program for final loopfield design assuming the parameters for the boreholes in the final installation are equivalent to those in the test bore. This is another reason that validation of the test borehole parameters is compatible with the final field configuration, as different hole depths will result in different thermal conductivity, undisturbed temperature, diffusivity and borehole thermal resistance values. Details pertaining to the general equation used for the calculation can be found in research literature (Mattison, et al., 2007 for example). Thermal Diffusivity Estimation Thermal Diffusivity may be estimated from a combination of the calculated thermal conductivity value (which is inversely related to the diffusivity) in conjunction with estimates of the specific heat, density and moisture content of the test bore. The thermal diffusivity reflects the rate of conductive heat transfer in the soil and helps determine the impact of neighboring borehole interactions on the final geothermal loopfield design. Diffusivity may also be determined from the drilling log by an experienced technician by assigning diffusivity values to the different rock types penetrated if formation thicknesses are known to generate a weighted average. This requires a reasonably accurate drill log for this effort.



Test Procedure Recommendations The American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) has determined a set of procedural recommendations for in-situ thermal conductivity/thermal response tests. These can be found in the ASHRAE 2007 HVAC Applications Handbook. Several of the key recommended procedures are as follows:

1. Time between drilling the test bore, loop installation and grouting, to commencement of data logging for the TC test should be 5 days minimum.

2. Undisturbed ground temperature measurement: The undisturbed ground temperature should be recorded prior to test start up (active heat generation into the borehole).

3. Test Duration: Test duration typically should be for 48 hours minimum. This allows for greater consistency of recorded data, and permits the removal of mild power variations or other inconsistent variables that can harm the integrity of the data.

4. Power Quality: The power standard deviation should be equal to or less than 1.5% of the average power and the maximum power variation should be less than 10% of the average power. The average heat flux should fall within the 15 to 25 watts per foot of borehole to best simulate the expected peak loads in the borehole.

As noted in 3. and 4. above, power supply must be consistent. For this reason we only use diesel generators for least deviation in power with a minimum of variation throughout the testing period for higher data integrity.

P

W

T¹

T²

F

Diesel Generator

kW

Data Logger

P – Circulation pump W – Water tank, heating elements T¹ - Temperature, to loop, °F T² - Temperature, from loop, °F F – Flow rate, GPM kW - Power

Grouted borehole, required for: - Heat transmission - Aquifer protection - State law

Circuit pipe insulation

Conceptual TC Test Configuration



December 19, 2012 Determination of Borehole Depth, Pipe Size & Grout Specifications Design of a ground loop requires that the building heating and cooling loads, including the duration of these loads, be calculated first to size the heat pump(s) to account for sufficient capacity and air flow. Once the loads and heat pump(s) are sized, the designer than evaluates the geology for key variables, including thermal conductance (the ability of the geology to move a specific amount of energy to and from the ground loop over the linear distance of the borehole) and undisturbed temperature. The geologic values are often ranged during the preliminary effort based on adjacent well logs or actual thermal conductivity tests in the area. This information is combined with the heating and cooling loads, the efficiency of the equipment to be used, the flow rate of water to feed the heat pumps to meet performance requirements, and other details specific to the physical location of the installation. Once this is known, the length of the borehole and diameter of the pipe to be used in the GHX borehole is calculated, with the objective of maintaining a specific temperature range that is compatible to operate the heat pump. Other information, such as calculating the fluid flow resistance (pressure drop) for the required flow rate is simultaneously considered in the design for circulation pump sizing. Even the type of grout may impact the performance of the ground loop and must be considered for optimum system performance. Once a preliminary field configuration is determined and a detailed site plan is produced, a thermal conductivity test may be required to finalize the number of bores, spacing and grout thermal conductivity. The test hole is selected to be compatible with the preliminary modeling to allow for expansion or contraction of the number of bores, spacing, etc., based on final calculations utilizing the hard TC test data, and utilize the test hole in the construction of the final ground heat exchanger. Once the test hole depth is determined the design must use the same borehole depth for final design as values can change at different depths even for the same geographic location. For this reason a TC test should not be programmed until preliminary modeling is completed to optimize test parameter selections. Sizing of a GHX should never rely on a “rule of thumb” or other assumptions, and should only be determined by an experienced, trained professional. This has been a common issue within the industry and slowed the growth of this proven technology. Relying on a driller or other asset to select GHX parameters without appropriate training or experience, no comprehension of the requirements of the mechanical system, and its interaction with the geology, is an invitation to a sub-performing or failed system. GHX Design_2012-12-19.docx

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