You may have several possibilities available for installing geothermal, some quite unique, using the mineshaft. Is this shaft flooded? What details regarding this mine can you provide, like what temperature is the water if any?

I don't know whether this mine was a gold mine but you probably have golden opportunities to creatively and perhaps very inexpensively integrate it into a geothermal project - without any drilling!

I would recommend contacting a Certified GeoExchange Designer in your area through the link below to discuss using this mine for an open loop, closed loop or standing column heat exchange source with either a standard geothermal heat pump or an active heating/passive cooling geothermal heat pump.

SR

Here is a link that might be useful: International Ground Source Heat Pump Association

Do you have a price broken out for the duct work? I assume it would be the same whether it is a air sourced heat pump or geothermal system. The same would be true for the cost for the zoning and ventilation system.

I knew I came to the right place. But to answer your question as far as the mine shafts go there are 2 shafts on the property one is ~14 round and 275 feet deep former exhaust shaft with a flooded mine 275 feet below that must be capped at the bottom by humping up stone and then filing with concrete to 6' above the roof of the mine. Once that's filled then we are free to fill with whatever we want (as long as its not hazardous).

As far as a breakdown of the quote he didn't tell me anything really just 21k for the ductwork, materials, and install and then the 3k for zones and 3k for air recovery system.

Once again any help is greatly appreciated.

What is the separation in feet between the 2 shafts? How far are they from the house you would like to build?

This may not a project for the usual contractors that either drill or bury horizontal pipes. You should consult with experienced professional engineers that are experienced in this field.

Sounds like a 'dream project' to me.

SR

I would say the shafts are separated by about 150' and the one hole is about 20' from the house. I also took your advice and reached out to a IGSHPA certified installer (the Certified Engineers weren't close enough) and he is looking into it. But its also worth mentioning that we are considering filling the shafts with fly ash which may (or may not) be a good heat conductor. But if we can use it then that would be ideal since we have a lot of fly ash and dropping it down the wells may not damage the pipe whereas dirt and stone would.

Your description sounds like a potentially perfect situation.

I would advise you not do ANYTHING to these mineshafts until you have an on-site in-situ evaluation from the professionals - you wouldn't want to (potentially) kill the goose that laid the golden eggs!

Don't forget to discuss passive cooling and standing column if you're able to do open loop.

I have heard of one commercial project where they are heating and cooling an 80,000sq ft factory using an abandoned mine shaft for at least 50% less than oil heating with additional capacity that has been developed and capped that they are willing to give away for free to anyone that would build near them.

Keep us posted.

SR

BTW....whats your best guess as far as how much both a 5-ton greenspeed or 5-ton geothermal install would cost with 3 zones and fresh air recovery. Assuming the geothermal can leverage the mine shafts and taking into account the 30% tax credit.

Even though I have US accreditation to design and install in the US I actually work in Canada. There are too many variables here to give any kind of meaningful estimate.

If you don't do geothermal, I would suggest cutting the best deal possible with a Carrier authorized dealer with the best reputation for the Carrier Infinity Greenspeed system. You may want to also include in your contract a Honeywell steam humidifier.

SR

I would also like to mention that I talked to one HVAC guy who says that even with a greenspeed unit its gonna be $500-$600 dollars a month to heat and cool my house??? I was like that can't be....I have an all ICF home (r-50 value), foam insulation in the attic, and even though the home is 3000 sq. ft (Above grade) and 2500 finished (below grade) I can't imagine it being that much. Even with 10' ceilings on the above grade level and all electric it just seems wrong. Any thoughts? BTW....I also had a geothermal guy come out and look at the property and hopefully he comes back with some good numbers (since i get the 30% tax credit + reduced rate on the holes). He also mentioned that he would rather do 2 3-ton units on opposite sides of the home and then I wouldn't have to do zones and I would get better air flow.

"... talked to one HVAC guy who says that even with a greenspeed unit its gonna be $500-$600 dollars a month to heat and cool my house"

When you hear statements like this it is a signal to look for another HVAC contractor.

Do you access to natural gas? What is the current electric rate for this area?

Ok I have some more info now. I have two geothermal quotes. 1 is for 2 3-ton carrier GT-PX units, no zones, no fresh air recovery for 46k before 30% credit. The other is for 1 6 ton 5 series waterfurnace unit, 4 zones, and no fresh air recovery for 39k before credit. The other quotes i received were for one 5 ton greenspeed with 3 zones (24k) and another standard system that had 2 3 ton units with a variable speed blower for (28k). It's so confusing I don't know who to believe anymore. It seems like all of these prices are high....but I would like other opinions. I still can't understand why the geo prices are so high when they don't have to drill the holes! Either way I'm also going to include the basement layout so we have a complete picture.

So the 39K geo quote goes down to 30K. That is only 2k more than the 2 system quote for 28k.
Maybe you can shave some money off the the 39K geo quote with less zones. Maybe only 2 zones instead of four.

Are these geo-quotes for a closed loop system where they install the loop or for a system where they access water from wells and is known as an open loop?

Have you estimated what the heat and cooling costs will be for the house? Have you estimated what the costs will be with the Carrier Greenspeed versus either Geothermal heat pump?