Installation
Connecting a Distributed Pump Kit to a Closed Loop System
All piping external to the unit is the re- sponsibility of the installer. The water pipe installation must be done in ac- cordance with local codes. If no local code applies, national codes should be followed. It is the contractor’s respon- sibility to know and adhere to all appli- cable codes.
Water inlet and outlet to the unit’s wa-
A pump module and hose kit (Figure 5) may be used to connect the unit to closed loop piping.
Using Antifreeze
In areas of the country where entering water temperatures drop below 45°F or where piping is being run through areas subject to freezing, the loop must be freeze protected by using an approved antifreeze solution to pre- vent the earth loop water from freez- ing inside the heat exchanger. Methanol, Ethylene, and Propylene Glycol are the most commonly used antifreeze solutions. Consult your geo- thermal unit supplier for the best solu- tions in your area.
Propylene glycol is not recommended in installations where the water tem- perature are expected to fall below 30°F. At extreme temperatures, the vis- cosity increases to the point where normal loop circulating pumps cannot maintain proper flow.
Calculate the approximate volume of water in the system by using the re- quirements detailed in Table 2. Add three gallons to this total to allow for the water contained in the hose kit and geothermal unit.
From Units To Units
W.O. W.I.
Bronze or Cast Iron Pump
Purging Cap (2)
1" MPT x barb fittings
1" MPT x barb elbows with pressure temperature ports and 10’ of rubber hose with 4 hose clamps
Figure 5: Pump module and hose kit
Table 2: Required Antifreeze by volume
Type of | Minimum Temperature for | |||||
| Freeze Protection |
| ||||
Antifreeze |
|
| ||||
10°F | 15°F | 20°F | 25°F | 30°F | ||
| ||||||
Methanol | 25% | 21% | 16% | 10% | 3% | |
|
|
|
|
|
| |
Propylene | 23% | 21% | 19% | 9% | 6% | |
Glycol | ||||||
|
|
|
|
| ||
Ethylene Glycol | 20% | 19% | 16% | 14% | 12% | |
Cleaning and Flushing
the Water Loop
After the piping system is complete, cleaning and flushing the water loop should be done to avoid trash settle- out in the condenser (Figure 6). An ex- tra pipe may be necessary to connect the hose kits.
1Electrical power to the unit should be disconnected.
2Double back the supply hose and connect directly to the return riser valve.
3Fill the water system with clean wa- ter using the water make up connec- tions. Note: Air vents should be opened during filling.
4With the air vents closed, start the circulating pump and then crack the air vents to bleed off the trapped air, as- suring circulation through all compo- nents of the system. Note: Make up water must be available to the system to replace the volume formerly occu- pied by the air that is bled off.
5With the air vented and the water circulating, the entire system should be checked for leaks with repairs made as required.
6Check and adjust the water/air level in the expansion tank.
7Operate the boiler (if used) by rais- ing the loop temperature to approxi- mately 85°F. Make checks per manufacturer’s instructions. During this operation, visual checks should be made for leaks that may have occurred due to increased heat. Repair as re- quired.
8Open the system at the lowest point for the initial blow down (making sure the make up water is equal to the wa- ter being dumped). Continue blow down until the water leaving the drain runs clear, but not less than 2 hours.
9Shut down pumps and boiler (if used). Reconnect the hoses to the proper supply/return for each unit, placing the
10Refill the system and bleed off any air. Add antifreeze to the system in cli- mates where ambient temperature falls below freezing, using the propor- tion of antifreeze shown in Table 2.
Figure 6: System flushing
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