Article on Geo-thermal residential heat
ElegantSolution
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I am looking for a back issue article in Fine Homebuilding that featured a home heated with a geo-thermal system that used a series of ditches in the yard. I can’t find it with the online index. Could I be confusing this with some other magazine article?
Replies
There are several houses that had geothermal, but as far as articles specifically about it:
FHB 133 Sept 2000 pp 104-109 "Installing a Geothermal Heating and Cooling System.
I don't know if there was a more current article on it.
jt8
"Determine that the thing can and shall be done, and then we shall find the way." -- Abraham Lincoln
Thanks. Must have had a brain cramp looking for that in the index.
Wow geo thermal heat, im sold :-)So since we are going to start building our house in July (fingers crossed) should I talk to my builder about this? or will he think im crazy?
How cost effective is it?Thanks.--Carlos
Call it "ground source heat pump," and if he's up on his state of the art technology, he's at least heard of it.
Whether or not it makes sense for you depends on a lot of things. Your builder should be able to help you with that.
I looked into it for my house. 25K. Forced air with an air exchanger was $8500. It is a big upgrade. For horizontal lines I needed 1000 feet of trench 6 feet deep. I didn't look into boring as I had the necessary land.It's expensive to be green sometimes.John
We have a 3 and 1/2 acre lot so I don't think we will need to look into anything special.
I have been reading for a few minutes now and it does always seem to be at least 10K more expensive than the conventional system! its gonna be hard to justify that.
We are also looking into some sort of solar technology...... we'll see where that takes us.
Whether geothermal works for you depends on several things. Probably top on the list is whether you're going to be in the house for 5 years or more. That is probably what you're going to need to pay off the additional installation expense. But from that point on, you're saving $$. However, if you're building a super-insulated house, this payoff time would ironically be extended out due to your lower overall monthly bill.
Another point: do you have good ground source heat pump installers in your area? An improperly installed unit can be a nightmare.
The primary difference in price is caused by the installation of the ground loop. A well drilling crew can put the loops in vertically, which leaves a very small footprint, but costs a bit more than the horizontal method which just needs trenches. But keep in mind if you're doing the horizontal loop that you have to be careful what you plant above it or whatever future construction might want to use that yard.jt8
"If people concentrated on the really important things in life, there'd be a shortage of fishing poles." -- Doug Larson
"Probably top on the list is whether you're going to be in the house for 5 years or more. That is probably what you're going to need to pay off the additional installation expense. "I would like to see some documentation on that..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Your results will vary, but 5 years is the typical number quoted. how many sources do I need?
What does a system like this cost? How long is the payback period for your geothermal heat pump system? This, of course will vary greatly depending on individual circumstances, but on average a typical home of 2000 square feet will cost between $14,000 - $18,000. This represents somewhere around double the costs of a conventional heating, cooling and hot water system. When it comes to payback, we at ECONAR often see a 3 – 5 year payback of these additional costs. Then it’s money in the bank from that point on.
http://www.econar.com/faq.htm#cost
The simple payback period is from three to five years for residences and in some commercial school systems
(big PDF file) www.heatpumpcentre.org/publ/<!---->HPCOrder/ViewDocument.aspx?RapportId=360
DOE gives a wider range:
the payback period can vary from 2 to 10 years
http://www.eia.doe.gov/cneaf/solar.renewables/rea_issues/html/geotsurv.html
Or do the math yourself based on:
Geoexchange systems represent a savings to homeowners of 30 to 70% in the heating mode and 20 to 50% in the cooling mode, compared to conventional systems.
http://geoexchange.us/documents/GB-003.pdf
jt8
"If people concentrated on the really important things in life, there'd be a shortage of fishing poles." -- Doug Larson
I ask for DOCUMENTATION."When it comes to payback, we at ECONAR often see a 3 – 5 year payback of these additional costs."That is not documentation.From the Heatpump Centre"Substantial energy savings in both residential and commercial are
proven. Current gas and electric pricing in the US has resulted in
payback periods of less than 5 years. With new residential construction,
the mortgage costs are less than savings resulting in an instant
positive cash fl ow to the owner.""The simple
payback period is from three to fi ve
years for residences""For example,
the cost of boring in Japan is about USD
100/m, as against about USD 20-30/m in
the USA or northern Europe. As a result,
the cost payback time of GSHP for ordinary
offi ce buildings is over 50 years.""The cost payback time when using
the system developed here was 17.7 years,
while that of a conventional GSHP system
is over 50 years in Japan."So what is it?What is the cost of cost of fuel? Is the cost of money included?Now lets look at this."This, of course will vary greatly depending on individual circumstances, but on average a typical home of 2000 square feet will cost between $14,000 - $18,000. This represents somewhere around double the costs of a conventional heating, cooling and hot water system. When it comes to payback, we at ECONAR often see a 3 – 5 year payback of these additional costs. Then it’s money in the bank from that point on. "Now my G&E was $1900 for the last year.Now the electric runs about $60/month during spring/fall months. No cooling and little of any heating. So about $700 of the electric is for lights and cooking.And there is a $25/month fixed consumer cost on the gas. And there is about $10-15/month that gas is used during the summer for WH, grill, and standing pilots on 2 furnaces. But it is kind of small and hard to breakout the furnace pilots. So I will just lump that in with the rest.So that is leaves about $1200 heating and cooling.When I built this house in 79 there was a natural gas energy shortage and just past the oil crisis. So I tried to build efficently. But information was lacking, I did not spend enough time to monitor the builder, and the builder had no concept of what I was trying to do.So some things did not work out way that I wanted.Walls are R-11 with 5/8 polyiso, but the sealing is poor. Windows thermal plane, but LowE was not commonly available at that time. The underslab and slab edge thermo breaks are minimal and the wrong type of insulation was used. The furnaces and WH was put into a closet with that was suppose to be sealed and have external combustion air vents. It has the vents, but it is not sealed off from the rest of the house.Some of these area are going to be fixed as I do some remodeling over the next couple of years.If I was building this house from scratch and just using modern materials/practices, but not trying for a supper insulated house my guess is that I would at least 20%, probably more.And the AC is ser 9, which was high for it's day. And standing pilot furances. Two although it is only 1600 sq ft so they are low eff.Going with SER 13 and 90% furnaces I would reduce my heating cooling by about 1/3.So a tight version of my house with modern HVAC would use about $600 for heating and cooling.Now if I replaced that with ground source and could save 1/2 of energy I would be saving $300 per year.How much of a geo sysem can I get for $1500, actually less when you figure current value of the money..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Most of the related sites will tell you that results vary. Lots of variables invovled. Is there something about 'results vary' that you don't like? There is no hard and fast number that they can give out that is going to apply to everyone's house.
The only way you could get a real ballpark number would be to talk to a local ground source installer to get a bid from him. Then talk to the regular HVAC guys to get your prices for standard nat. gas/central-ac. Obviously as you increase the efficiency of the standard furnace/AC, you're going to pay more thereby reducing the price difference (as well as savings) of it versus the geothermal. Then look up your utility rates. Then assemble a guess of your savings and how long your payback would be. Results vary.
And as always, insulation always gives you more bang for your buck than a fancy heating/cooling system or alternative energy source, but even with a super-insulated house, you're going to need some form of HVAC system.
jt8
"If people concentrated on the really important things in life, there'd be a shortage of fishing poles." -- Doug Larson
Another interesting thing I've noticed is that some of the people who do NOT like the geothermal units try to inflate the payback period.
When you're looking at a $10-18k price tag for a geothermal setup, your payback with geothermal is not based on dividing the savings into $10-18k. If you were going to have to buy a furnace/AC unit anyway, your payback is based on the price of a geothermal MINUS what the traditional furnace/AC would have cost.jt8
"If people concentrated on the really important things in life, there'd be a shortage of fishing poles." -- Doug Larson