Geothermal Heat

[Bob B.]

I'm considering a geothermal heating/cooling system. Has anyone had one installed? Has anyone looked in to it and decided against? It's supposed to be quite expensive to install (10K?), but cuts monthly heating bill down to near nothing. Can periodic maintenance be expensive?

We live in Michigan, and spend about $2,400 per year on heating fuel. Our furnace was in the house when we moved in. It's only about 8 years old, but is not very energy efficient. I think it was a cheapie when purchased. It burns fuel oil - an expensive way to heat a house - basically diesel fuel.

It would probably be next spring before we had it installed. I'm not necessarily sold on geothermal, but am considering it. Any words of wisdom would be appreciated.

[lorraineb]

I would approach this with caution. As with all things, scale and efficiency brings down cost. If it isn't mainstream yet, my guess is that there will be a lot of first adopter costs involved, most likely with maintenance and repair costs. I would avoid it for this reason.

[Bob B.]

Geothermal heating isn't *that* new. It's probably been used for residential heating for 10 or 12 years? It seems like it's been fairly popular for 5 or 6 years? Yes, it's still new, but I don't really think I'd be in the "early adopter" class.

I've done some simple research since starting this thread. Systems for a house my size would be (very roughly) 10-12K. Depends on the size of your house, and (having a fairly small house), sounds like I could get away with a 2 ton or 3 ton heat pump.

Also, I have quite a bit of land around my house, so the piping would be set horizontally rather than vertically. Would save on drilling/installation costs. So, my still fairly uninformed guess is that I would be closer to the 10K cost than the 12K cost.

The real question is how much my current heating (and to a lesser extent cooling) expense would be reduced. On-line I found estimates of 40-60% and 30-70% for heating and 20-50% for cooling. We live in Michigan, and heating is much more expensive.

I made a simple excel spread sheet. If the cost is 12K, and saves 60% of heating costs, geothermal will break even between year 9 and 10. If the cost is 14K or greater and saves 40% of heating costs, the system will break even between year 16 and 17. Quite a difference. Systems apparently last 20-25 years.

I can have contractors bid the job, and get purchase and installation costs close to nailed down. Really, what I need to know is how much yearly heating costs would be reduced. I assume it's very climate dependent.

[simpletron]

I looked into geothermal heat pumps a few years ago to an aging AC/heat pump and it wasn't cost effective even if it eliminated 100% of the extra electricity during the summer and winter for the AC/heat pump, which is less than how much you spend on heating oil. I live much further south than you do and electricity is fairly cheap at 9-10 cent/kwhr. You might want to check out http://www.dsireusa.org/ to see if there are any rebate programs for you.

For maintenance, It should be very low cost compare to outdoor AC/heat pump. Using liquid at a temperature closer to room temperature(than air temp) to transfer heat to or from, is much easier and more efficient for a heat pump to do. Additionally geothermal heat pumps generally are installed indoors.

I would assume a number closer to the low end for efficiency, just so I can't be disappointed. If it came out higher after installation, I'll just be happy to save even more money. But that's just my way of thinking.

Personally I found adding insulation(31 ft^2 rolls of unfaced R-30 is like $15), sealing up ducts with aluminum tape, and sealing windows, doors, etc. with spray foam/caulk to be a very cost effective method to reduce your energy bills for heating/cooling your home and made the temperature in my home more even and comfortable. I spent nearly $1000 doing this and I saved about $300 annually on electricity.

[GrimJack]

If you are considering horizontal vs vertical geo-thermal, remember that the horizontal set up has to be below the frostline to be as efficient as possible - when I ran the numbers a couple years ago it seemed the vertical seemed to win.

[GrimJack]

If you are considering horizontal vs vertical geo-thermal, remember that the horizontal set up has to be below the frostline to be as efficient as possible - when I ran the numbers a couple years ago it seemed the vertical seemed to win.

[marvholly]

DIL's parents put in a(horizontal I believe) a few years ago. Another cost factor to consider is that they had to move out of the house for (supposedly) a month that turned into >3 months.

So they had hotel, meal, & laudromat added expenses for ALL that time. Plus the issues of living in a single romm vs. at 10 rm, 3 bath house.

[Bob B.]

DIL's parents put in a(horizontal I believe) a few years ago. Another cost factor to consider is that they had to move out of the house for (supposedly) a month that turned into >3 months.

So they had hotel, meal, & laudromat added expenses for ALL that time. Plus the issues of living in a single romm vs. at 10 rm, 3 bath house.

Please explain more as to why they had to move out? Was it because of comfort? Too warm in the house during summertime installation?

[marvholly]

Please explain more as to why they had to move out? Was it because of comfort? Too warm in the house during summertime installation?

I co not remember the complete reason(s) but part was that so much land & basment area had to be torn out plus some utilities (electric?) HAD to be totally turned off.