A. This Section includes exterior piping for vertical, direct-buried, ground-loop, heat-pump systems that operate between 23 and 104 deg F.

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1 SECTION PART 1 - GENERAL 1.1 RELATED DOCUMENTS A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section. 1.2 SUMMARY A. This Section includes exterior piping for vertical, direct-buried, ground-loop, heat-pump systems that operate between 23 and 104 deg F. B. Related Sections: The following Sections contain requirements that relate to this Section: 1. Interior heat pump system piping and accessories are specified in Division 23 piping Section "Hydronic Piping". 1.3 PERFORMANCE REQUIREMENTS A. Components and installation shall be capable of withstanding the following minimum working pressure, unless otherwise indicated: 1. Ground-Loop, Heat-Pump Piping: 160 psig. 1.4 SUBMITTALS A. Product Data: For the following: 1. Pipe and fittings. 2. Joining method and equipment. 3. Propylene glycol solution. 4. Glycol make-up unit. B. Field quality-control test reports. PART 2 - PRODUCTS 2.1 MANUFACTURERS A. Manufacturers: Subject to compliance with requirements, provide products by one of the following: ( )

2 1. Geothermal Heat Exchanger (Underground) Closed-Loop Piping: a. Phillips Driscopipe, Inc. (Driscopipe 5400 Climate Guard Series) b. Charger Plastics (ADD#4) 2. Propylene Glycol: a. Dow Chemical Co. (Dowfrost HD). b. Ohio Chemical Services (Protocol NT). c. Interstate Chemical (Intercool NFP). 3. Glycol Make Unit: a. Wessels, Inc. (Model GMP-13050). 2.2 PIPE MATERIALS A. Geothermal Heat Exchanger (Underground) Closed-Loop Piping: Acceptable pipe material for the underground buried portion of the geothermal heat exchanger loop is polyethylene, conforming to the following requirements: 1. General: All pipe and heat fused materials shall be manufactured from a virgin polyethylene extrusion compound material in accordance with ASTM D-2513, Sections 4.1 and 4.2. Pipe shall be manufactured to outside diameters, wall thickness, and respective tolerances as specified in ASTM D Material: The material shall maintain a 1600 psi Hydrostatic Design Basis at 73.4 degrees F per ASTM D-2837, and shall be listed in PPI TR4 as a PE3408 piping formulation. The material shall be a high density polyethylene extrusion compound having a cell classification of PE355434C with a UV stabilizer of C, D, or E as specified in ASTM D-3350 with the following exception: This material shall exhibit zero failures when tested for 192 or more hours under ASTM D-1693, condition C, as required in ASTM D Dimensions: a. Pipe with a diameter less than 3" (nominal) shall be manufactured in accordance with ASTM D-3035 with a dimension ratio of 11 (for thermal and performance reasons). b. Pipe manufactured with a diameter of 3" and greater (nominal) shall be manufactured in accordance with ASTM D-3035 with a minimum dimension ratio of If the pipe is used in a vertical bore application of over 200 ft. it shall be manufactured in accordance with ASTM D-3035 with a dimension ratio of 11 (for thermal and performance reasons). 4. Markings: Sufficient information shall be permanently marked on the length of the pipe as defined by the appropriate ASTM pipe standard. 5. Certification Materials: Manufacturer shall supply a notarized document confirming compliance with the above standards ( )

3 6. Warranty Materials: Manufacturer shall supply a written warranty of 25 years covering manufacturing defects in materials and providing material replacement and labor allowance. 2.3 PROPYLENE GLYCOL/WATER SOLUTION A. Provide a sufficient quantity of commercial inhibited propylene glycol in the hydronic system to provide a solution which will prevent the water from freezing at an outdoor ambient temperature of -10 deg. F. Glycol shall meet the requirements of ASTM D Conduct refractometer tests initially and periodically over the warranty period to assure that a proper mixture is maintained. Advise the Owner in writing of the type of glycol, total amount provided and guaranteed lowest outdoor ambient temperature at which freezing will be prevented. B. Glycol/water solution shall be premixed with de-ionized water conforming to ASTM D1193, Type II reagent water standard. Solution shall be pumped into the system by the Contractor. 2.4 GLYCOL MAKE-UP UNIT A. Provide a prefabricated, automatic make-up unit for the glycol/water system. B. The package shall be designed to occupy a minimum amount of floor space to operate on a standard 110 V, 60 Hz electrical circuit, and to maintain a fill pressure in the glycol system of 12 psig (adjustable). C. The unit shall feature a cut-off and alarm arrangement which will stop the pump in case of excessive pressure, or a low solution level, and activate an audible (which can be silenced) and a visual alarm. A 110 V signal shall also be available for a remote alarm. D. A 50 gallon translucent polyethylene solution container, complete with lid, shall be mounted on the pumping assembly and shall include a strainer and a shutoff valve. A 3/4" NPT glycol solution recovery line shall be piped in from the system relief valve outlet to the solution container, through its lid in such a way that the lid can be removed for filling and mixing. E. The pumping assembly shall be mounted in a sturdy steel frame with legs to keep it off the floor. It shall include a 1.8 US GPM at 50 psig pump, a 1/3 HP motor, a magnetic starter, a pressure tank with a pressure control, a priming valve, a PRV, a shutoff valve and a pressure gauge. It shall be connected to the system with a 1/2" NPT connection ( )

4 PART 3 - EXECUTION 3.1 EARTHWORK A. Excavating, trenching, drilling, warning tape, and backfilling are specified in Division 31 and Division 23 Section "Common Work Results for HVAC." 3.2 PIPE APPLICATIONS A. Exterior Geothermal Heat Pump System, All Sizes: Use only polyethylene pipe with heat fusion welded joints. 3.3 PIPING INSTALLATION A. Geothermal Heat Exchanger (Outdoor) Closed-Loop Piping: 1. All work involving the fabrication and installation the geothermal heat exchanger loop shall be provided by a Loop Subcontractor directly responsible to the Contractor. The Loop Subcontractor (Drilling Contractor), must have a current IGSHPA certification, having completed an IGSHPA training course in the fundamentals of design, installation, and operation of ground source systems, and having passed the IGSHPA certification examination and pipe fusion tests. 2. Geothermal heat exchanger fabricators must have completed a heat fusion school in which each participant has performed heat fusion procedures under direct supervision of a IGSHPA Certified Heat Fusion Technician. The Fusion Technician must be thoroughly familiar with heat fusion procedures, and have had formal training and testing at a heat fusion school under direct supervision of an IGSHPA certified instructor. a. Certified pipe fusion technicians shall attend a retaining school every three years. A single failure of a fusion joint will void the certification, and the technician must be retested to demonstrate satisfactory performance. 3. Local and State laws and ordinances as they pertain to buried pipe systems shall be strictly followed or a variance obtained. 4. Prior to any excavation, trenching, or drilling, all buried utilities, drainage, and irrigation systems shall be located and flagged by the appropriate utility and contractor representatives. 5. The Loop Subcontractor (Drilling Contractor), is responsible for all excavation, drilling, installation of outdoor horizontal and vertical geothermal piping, casing, grouting, and control of surface water runoff and erosion control. Immediately following the drilling of each bore hole, the loop contractor shall insert and pressure test loop, and grout bore hole. In no case shall a bore hole be left open, in order to prevent contamination and/or cross contamination of the aquifer ( )

5 6. All exterior Geothermal Loop Heat Exchangers (GLHE's) shall be constructed of high density polyethylene pipe, SDR-11 (PE3408) as herein specified. Each GLHE shall be closed by means of single or double-elbow style U-bend at the bottom of the loop. The U- bend shall be constructed and attached to the GLHE using the heat fusion bonding method, prior to insertion into the bore hole. No other fusion joints are permitted on the vertical portion of the GLHE. 7. All fusion joints and loop lengths shall be checked to verify that no leaks have occurred due to the fusion joining or shipping damage. 8. All loops will be pressure tested before and after installation, and all horizontal components of the ground heat exchanger will be pressure tested prior to backfilling. 9. Heat exchangers will be tested hydrostatically at the smaller of 150% of the pipe design rating or 300% of the system operating pressure. 10. No leaks shall occur within a 30 minute period. 11. Flow rates and pressure drops will be compared to calculated values to assure that there is no blockage or kinking of any pipe. 12. Before backfilling the trenches and bore holes, all systems shall be flushed and purged of air and flow tested to ensure all portions of the heat exchanger are properly flowing. A portable temporary purging unit shall be utilized and shall consist of the following: purge pump--high volume and high head; open reservoir; filter assembly with bypass; connecting piping, and connection hoses. 13. Using the purging unit described above flush and purge each Geothermal Loop Heat Exchanger system until free of air, dirt and debris. A velocity of 2 ft./sec. must be maintained for a minimum of 15 minutes in all pipe sections to remove the all air. This flushing and purging operation should be conducted with the water source heat pump (indoor metal) piping isolated with shut off valves. After the Geothermal Loop Heat Exchanger is completely flushed of air and debris, open the isolation valves and permit circulation through the heat pump portion of the system until the entire system is flushed and purged. The isolation valves at each of the heat pump units are to be closed during this activity, or the hoses to each pump unit joined together to form a loop. Do not flush and purge through the heat pump unit. 14. Do not allow the acid solution used to purge and flush the indoor metal pipe system to the heat pump units to become mixed with the solution in the GLHE. 15. Utilizing the purging unit, conduct a pressure flow test on the Geothermal Loop Heat Exchanger to ensure the system is free of Blockage. If the flow test indicated blockage, locate the blockage systematically clamping off loops with a pinch-off tool, remove the blockage, then repurge and conduct the pressure and flow test again until all portions of the system are flowing. The flow test must be observed and approved by the Architect. 16. The Geothermal Loop Heat Exchanger inspection report is to be filled out by the Contractor and is to be witnessed by the Architect. 17. The Contractor shall provide the Owner with a copy of a dimensioned site layout showing the location of the buried GSHP piping relative to a permanent structure and buried conduits ( )

6 18. The Contractor shall make available on request, a certificate describing the specifications and the start-up performance test results of the system. 3.4 PIPE JOINT CONSTRUCTION A. Fusion Welded Connections (Polyethylene Pipe): 1. The only acceptable method for joining buried pipe systems is by a heat fusion process. 2. Polyethylene pipe shall be butt or socket fused in accordance with pipe manufacturer's procedures. Sidewall fusion joints (in accordance with pipe manufacturer's procedures) for take-offs from 3" piping and larger is acceptable. (ADD#4) 3. Fused transition fittings with re-enforced threads shall be used to adapt to black steel, copper or brass valves. Barbed fittings are not permitted in polyethylene pipe. 3.5 FIELD QUALITY CONTROL A. Piping Tests: Fill piping 24 hours before testing and apply test pressure to stabilize piping. Use potable water only. B. Hydrostatic Tests: Test at not less than 1-1/2 times the pipe working-pressure rating allowing for static pressure of borehole depth. 1. Increase pressure in 50-psig increments and inspect each joint between increments. Hold at test pressure for 30 minutes. Slowly increase to next test pressure increment and hold for 30 minutes. After testing at maximum test pressure, reduce pressure to 30 psig. Hold for 90 minutes, and measure pressure at 30- minute intervals. Repair leaks and retest until no leaks exist. C. Prepare reports of testing activity. END OF SECTION ( )

SECTION HIGH DENSITY POLYETHYLENE PIPE AND FITTINGS (PRESSURE PIPE)

SECTION HIGH DENSITY POLYETHYLENE PIPE AND FITTINGS (PRESSURE PIPE) SECTION 02623 HIGH DENSITY POLYETHYLENE PIPE AND FITTINGS (PRESSURE PIPE) PART 1 - GENERAL 1.1 SCOPE OF WORK A. Furnish all labor, materials, equipment and incidentals required and install high density