The first battery powered cars I came in contact with (City Car) were glorified golf carts. The reason we are able to revisit battery powered vehicles is because of advancements in batteries.
Where earth loops are concerned there is no such recent advancement in any of the components.

Posted By Cgallaway on 03 Mar 2013 10:06 AM
As evidenced by my first few posts here, I didn't even have a decent phrase
that I could Google to find out more.

Maybe that should have discouraged you from listing so many "We all know..."
factoids -- directly contradicting facts that "we all" DO know ...well, all but one.

"Alice laughed. "There's no use trying," she said: "one can't believe impossible things."
"I daresay you haven't had much practice," said the Queen. "When I was your age,
I always did it for half-an-hour a day. Why, sometimes I've believed as many as
six impossible things before breakfast."

Got a zip code or other location information (for weather data purposes)?

Building a geo system big enough to heat & cool an uninsulated house could even cost more than demolishing the house and putting up a code-min house heated with an air-source heat pump, and even with the lower efficiency of the air source heat pump it would cost a heluva lot less to heat and cool than the high-efficiency GSHP with the efficiency-disaster building envelope.  If you're keeping the house, without making it a LOT more efficient from a heat loss point of view a fossil burner is probably your only reasonable/affordable option.

Even adding a vapor barrier to a stucco clad wall comes with severe risks if the stackup can't accomodate it.  Stucco & masonry are often referred to as "reservoir cladding", since they can take on significant quantities of rain/dew/interior-air-condensation before they actually appear wet or weep liquid moisture.  When the sun shines directly on a reservoir cladding it raises the vapor pressure of that stored moisture, releasing it in very intense bursts. If you put an interior side vapor barrier up you end up with liquid condensation running down the interior side of the vapor barrier puddling  on top of the foundation sill, band joist, or subfloor, depending on exactly how the thing is built.  This is also a problem with dense-packing cellulose right up against the lath- the high intensity bursts of moisture load up in the cellulose, which may eventually saturate and lose insulating value until it dries, but even if it doesn't saturate, high moisture cycling can make even 4lb/ft cellulose settle due to the dimensional changes and creepage that will occur.

All reservoir claddings need sufficient back-ventilation (preferably to the outdoors) to keep the framing dry.  In plank or plywood sheathed stucco clad homes there is usually 1-2 layers of 15# felt on the exterior of the sheathing, and a 1/2-1" air gap to the steel or wood lath on which the stucco was applied, with both a bottom screed openings and top edge gaps to promote convective flows.   Any time you apply heat to the wall (from the interior or the exterior), the convective flow increases, purging moisture from the cavity between the stucco and the sheathing.  When you insulate such a wall, the amount of heat reaching the stucco from the interior is dramatically reduces, which increases the size needed on the vents to the cavity to be able to purge moisture. But with proper back-venting of the stucco, and properly-lapped window & door flashing, dense-packed cellulose and NO VAPOR BARRIER can be protective of the structural wood.   Plan-B would be open cell foam (more air tight, reasonable drying rates, but no moisture buffering capacity), followed by injection foam (better drying, somewhat higher R, not as air tight as o.c. foam, and way more expensive.)

If the interior is going to be gutted, a flash- 1" of closed cell foam followed by cellulose can work too, and is somewhat more air-tight than cellulose alone. More than 1" of cc foam is too vapor retardent, and can put the sheathing at somewhat higher risk. (In new construction putting rigid XPS or foil-faced polyiso on the exterior of the sheathing facing the vent space is the right way to go, since that isolates the susceptible wood from the moisture drives off the stucco.)

Without a vent cavity insulating the stud bays with ANYTHING effectively eliminates the drying air flows, the insulation will have periods when it's actively wet, and the stud edges will rot.  Even open cell foam (which is air tight, but sufficiently vapor open that some drying toward the interior) would not yield sufficient drying rates in all but the very DRYEST of climates, and would need 2' overhangs on the eaves to limit active wetting during rainstorms.

looby you are right, the "we all know" was too much.

Dana,56143, Jackson, MN...Southwest MN, 10 miles north of Iowa, 90 miles east of South Dakota. This is actually one of the best older homes in town. There will be no demolishing and no gutting. The most I planned on doing would be just enough to get my wiring in, which should able to do mostly from the basement. Thanks for the info and the time. I think you just made up my mind not to pursue the wall insulation issue any further. Perhaps natural gas is the way to go. I don't really know anyone with a 2 stage furnace, so perhaps that will close the comfort gap between the existing 30 yr old gas furnace and the expected comfort of a geothermal. As to the electric furnace in the attic....that might be getting replaced soon. If it keeps contributing $200 a month to the electric bill (first electric furnace I've seen, and still have a month until the next bill to see what it costs when fixed).

All, thanks again. I think I will consider this matter closed.

Jackson, MN..hmm. I was a foreign exchange student in Trimont, lived on a farm between Trimont and Jackson. Good luck with your new gas furnace!

Dana1, very informative & interesting post. Thanks for taking the time.
Do you have any comments on EIFS (a/k/a Dryvit, a/k/a synthetic stucco)?

It seems to be working well for us. We did a major renovation to an early 1950's residence
with no insulation in the walls (stucco : concrete block : 1" air gap : plaster on lathe). There
was no way to insulate inside, so we went with EIFS (polymer stucco on 2" rigid foam) over
the existing stucco. That was 12 years ago, Philly 'burbs -- no obvious problems, so far.

- is EIFS a reasonable possibility for the OP?

- any moisture-management problems that I should be looking out for?

EIFS has to be done perfectly on day one, and needs to be maintained over time to avoid moisture problems- it's not as forgiving as hard-coat stucco with back venting. (Do a web search on all terms: vancouver leaky condo EIFS ) Done right it can work, but you can't let any dings or damage go or it'll catch up with you. The drier the climate, the more forgiveness you get out of it. (Vancouver is the opposite of a dry climate, being practically a temperate rain-forest type of climate, ergo a bigger risk there than in high-dry AZ, etc.)

The wall insulation issue can and SHOULD still be investigated, but it's not a no-brainer. Even if it turns out you really can't insulate, at the very least AIR SEAL the place, starting with all known big leaks first. When you run out of ideas, PAY somebody for a blower door test with IR imaging to track down the rest. The payoff in comfort and reduced fuel use will be worth it.

With a ducted gas-fired system, take the time to air seal all the duct joints/seams with duct mastic, and caulk all of the register boots to the floor/wall, etc, and insulate at least the supply ducts to R6.