[jeff5may]

Jlaw,

I saw your original post on this subject in the manifesto thread and thought your initial questions had been answered, and that you had been pursuing a stategy.

So what have you come up with in the meantime? Have you decided which way to go with the idea?

I see you posted that you may want to reconfigure your 3 ton heat pump into an air-to-water unit that transfers heat to and from your stream. This approach will not get you as much heat transfer as a true underground loop, since the stream temperature tends to follow the outdoor temperature. You also have a long distance to travel between your heat pump and the stream source, so the pressure drop in your loop would dictate a larger size pipe and a larger pump than if it were closer to you. However, this distance underground could work in your advantage by transferring more heat into the ground. Some temperature logging would be needed to figure out the details, especially during the high demand times of the year.

A modified system would perform better on those extremely hot and cold days than what you have now, but during the other 80-90% of the year, you might not save much energy over a 15 SEER unit. A proper energy audit or heat load analysis is always a good first step to take before you start modifying your existing HVAC system. A large portion of homeowners discover that sealing and insulating their existing envelope is all they need to do to reduce their energy consumption to a much lower level.