I started looking around this forum last week and was amazed at some of the good feedback people were getting.  I welcome any suggestions for my situation as well.

The setup:
I am located in Ogemaw County, have a 3000 sq ft (2300 above grade, 700 walkout basement), ranch style home on 8.5 wooded acres (long and narrow).  My house was built in 1998 and was a rectangular ranch home with no basement.  The original house has a forced air downflow 85% efficient furnace with "central return" burning propane (56,000 btu).  In 2005 (right before I purchased) an addition was added with a walkout basement underneath.  There is a utility room in the basement containing a second furnace.  This one is a 90% efficient upflow furnace with return ductwork burning propane (80,000 btu).  The two sections of the house are connected and open to each other and I notice that both furnaces run about the same amount.  I burned ~1,500 gallons of propane last year and am looking to trim heating costs with a GSHP (among other things).

The system:
I have a little background in HVAC and installed central air conditioning units in each furnace.  What I want to do is remove my air units and purchase a split system geo unit with new coils.  I want to run two 2.5 ton coils (one in each furnace) from one 5 ton split system and use well water as the heat source/sink.  Excess water will be drained into a drainage ditch.

Questions:
1. I know I will need ~10-12 gpm to run the system (manufacturer recommendation).  My current well record tells me my well will get 12 gpm but has a pump capable of 10 gpm.  Can I have another well drilled to supply the geo only?

2. If I have a second well installed I'd like to keep pumping costs down by having the well pump come on with the geo and not have a well tank (or only a small one).  Is this doable? (well water test shows good water)

3. Can I use the two 2.5 ton coils with a single 5 ton geo (single stage) and run all of it from a single thermostat? (I think I have a pretty good way of setting up the T-stat)

4. This may belong to a different topic, but what can I do to the exterior of the home to improve insulation (insulation board, wrap, etc...)?

Any help, suggestions, or feedback is appreciated!  When this project is done, next comes a windmill!

Thanks,
MJ

MJ,
Need to start with a Manual J loss calc.
Not going to be able to have one heat pump run to coils unless you go water to water and use hydronic coils.
I'm not a fan of split systems.
You may find it's not much more to buy package units which will also have longer warranties and be cheaper to operate.
Good Luck,
Joe

Curious..how is a split more expensive to operate?

Generally speaking you would use the furnace as back-up without the heat pump running. With electric auxiliary it can run at the same time as the heat pump. Now this isn't in stone, but you can imagine with the installation you described that you wouldn't want to run the heat pump while your furnace blows through the fan coil (your head pressures would go through the moon). Also as propane gets higher, it is often more expensive than even an electric coil to operate.
J

I have heard of splitting line sets like that but only in the reference of" dont do it " Mitsubish USED to allow it on some ductless units
First and foremost you are definitely going to void warranty
2nd oil return
3rd equal length line sets
4th equal distribution of refrigerant
5th because they both definitely have to run at the same time why bother
if you have the time to figure out 1-4 and more you should have plenty of time to figure a way to run ducts from point a-b and zone the air