OPEN LOOP SYSTEMS PRODUCE MORE BTU'S PER TON AND ARE VERY EFFICIENT AND CHEAPER TO INSTALL.  THEY ARE IDEAL IF YOU HAVE SANDY SOIL, STEEP SLOPES,  WOODED LOT, ETC.  GOOD WATER QUALITY, WATER PRESSURE AND  POND TO DISCHARGE TO ARE REQUIRED.   ASK FOR A  WATER SPEC SHEET AND GPM REQUIREMENTS.  INCOMING WATER IS NOT SOFTENED AND UNFILTERED EXCEPT FOR THE FILTER WE PROVIDE BECAUSE WATER FLOW CAN'T BE RESTRICTED.  YOUR WELL PUMP WILL RUN OFTEN AND A LARGE SIZE STORAGE TANK IS RECOMMENDED.  EXITING WATER DOES NOT HAVE ANYTHING ADDED TO IT.  IT IS JUST COLDER OR WARMER.   WATER SHOULD FLOW DOWNHILL AND NOT BE RESTRICTED OR USED IN FOUNTAINS ETC.  YOUR POND WILL NOT FREEZE IN A 10 FOOT CIRCLE WHERE THE WATER ENTERS.   POND MAY BE STOCKED WITH FISH.  CLEAN FILTER AS NEEDED.                

If you have an open loop system you will need a place to discharge the water exiting from the geothermal system.    The water is the same water that came from your well, only it's a little colder in the winter or warmer in the summer. 

If you have soil that tends to be mostly sand or gravel in the first 5 feet, then an open loop might be the perfect solution.

Open loop systems are much less costly to install because there is no need for underground loop materials and labor.   If you have well water that meets the water specs provided to you when you call, and a place to discharge water, it is worth considering.  Open loop systems are very efficient systems.  If you don't mind cleaning the incoming water filter as needed, then this could be perfect for you.