Installing geothermal heating and cooling systems

[FangKC]

An article in the Star about use of geothermal systems to heat and cool homes.

http://www.kansascity.com/105/story/1760807.html

[nota]

Just a question-the one geothermal home that we built in the 70s had to have the pipes laid horizontally in the yard, now that they are able to do it vertically-would this be able to be installed in a city lot home? That is if the owner wanted to do it or would it only be logical for new construction?

[jdubwaldo]

nota - we are looking at replacing our old system with a heat pump and new furnace and they mentioned they could indeed do geo at our house with vertical pipes.  It would be about twice the expense.  It's a big mess, but if you are willing to put up with that and the added expense, yes it can be done.  According to Neal harris and AB May.

[LenexatoKCMO]

As I understand it, the difficulty with the vertical pipes can be the presence of rock - you have to be able to drill pretty deep without hitting substantial rock or worse bed rock.  I know some folks who were planning to have it done on an urban lot in KC but were advised that the geology of their lot would make it impossible. 

[taxi]

It's hard to know until they start to dig. They can go through rock and almost always do, since they typically go down at least 200 feet. It's just way cheaper to lay them horizontally, if you have the space. You would only go vertical if you don't.

[Highlander]

As I understand it, the difficulty with the vertical pipes can be the presence of rock - you have to be able to drill pretty deep without hitting substantial rock or worse bed rock.  I know some folks who were planning to have it done on an urban lot in KC but were advised that the geology of their lot would make it impossible. 

It seems like horizontal shallow pipes would be too close to the surface to be effective (given to seasonal fluctuations in temperature).  In KC, unless you live in a sizable valley with some significant alluvium, you are going to hit bedrock well before 200' (vertical depth) and in the vast majority of locales, within a few feet of the surface.  That's the nature of the beast.   

[aknowledgeableperson]

It's just way cheaper to lay them horizontally, if you have the space. 

At the same time doesn't going horizontally require a backup heating system.  The reason being that it becomes less effective when the temps reach freezing or zero (can't remember the break point).

[taxi]

No, they lay them something like 6' below ground, below the permafrost line, where the temp. is pretty much 55 degrees. It's much cheaper to trench than to drill. Again, you have to have enough land.

[cityscape]

My parents put in a system 11 years ago.  It has already paid for itself (according to my dad).  They live in a 3500 sq ft house and have a barn.  They are all electric and their monthly electric bills average $170 (Note:  KCPL gives you a 30% discount if you are all electric).  I do remember that when they were putting in the system that they mentioned drilling vertically is practically twice as efficient as having horizontal trenches.  They also mentioned a third method which is to place the pipes in a deep lake or pond.  If I could afford it I would definitely put in a geothermal unit.  Some of the added benefits to geothermal include a bi-product of hot water, so most require you to have an additional hot water tank.  You also don't have to have an exterior A/C unit which is obviously more aesthetically pleasing. 

[nota]

nota - we are looking at replacing our old system with a heat pump and new furnace and they mentioned they could indeed do geo at our house with vertical pipes.  It would be about twice the expense.  It's a big mess, but if you are willing to put up with that and the added expense, yes it can be done.  According to Neal harris and AB May.

do you mean twice the price as traditional heating/cooling or twice the price as horizontal pipes?

[jdubwaldo]

They indicated to me twice the price of a dual stage heat pump and new furnace for a full geothermal system in our house.  Options we looked at were 10-12K.  He said a geo system would be $20-25K.  He didn't do a full quote for geo but a ballpark based on the size of our house.

[nota]

They indicated to me twice the price of a dual stage heat pump and new furnace for a full geothermal system in our house.  Options we looked at were 10-12K.  He said a geo system would be $20-25K.  He didn't do a full quote for geo but a ballpark based on the size of our house.

Wow-the differences in price weren't nearly so much back "in the olden days."

It would take many many years to save enough on your bill to pay for the difference in the outlay. I think there is some kind of tax rebate now that one would have to take into account, but still . . .

[jdubwaldo]

The tax rebate is 30%, up to $1500 for a standard system.  Don't quote me on this - but I BELIEVE the rebate is 30% w/o a cap for a geo system..........  Saying 12K for a heat pump you would get 1500 back, but for a 20K geo system you could get 6K back, so would be 14K.  If I'm not goofed up, this would be worth talking about.