Thread: VERY low energy efficent home.. geothermal?
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Apr 24th, 2009 09:30 AM
#1
VERY low energy efficent home.. geothermal?
Hello,
A month ago my father got a company to come in and do an ecoENERGY report on our house.
We just got the report back last week. The guy said he has never ever seen a house score as low as ours... we got 21%
This house is over 150 years old, and almost zero renovations have been done on it since it was built, now my dad is serious on getting things done to the house.
The report said there was 4 major problem areas
1. Basement has 0 insulation
2. Attic has 0 insulation
3. Wood stove should be replaced with an energy efficient wood stove.
4. Oil furnace should be replaced with an energy efficient furnace.
Surprisingly replacing windows would do very little.
Anyways he for sure is going to insulate the basement and attic, and may think about the wood stove upgrade, but probably won't do the furnace.
The report says if we do all the recommended upgrades, the house should go to 55% efficiency.
Another thing interesting about the report was that the average house will have all the air exchanged with outside air every 2.5 hours. His house is doing it every 7 minutes....... wow. Now we know why it was so freezing cold this winter.
Anyways, my father is also thinking about installing geothermal heating. He lives on a 100 acre farm, so space is obviously not an issue. But how great is it really? He did meet with the installer and the guy said that we shouldn't expect it to heat our house 100% and we will still need to burn oil/wood in December, Jan, and Feb, but the rest of the months it should be able to sustain itself.... What are your guys thoughts on it? We both are doing research since it is obviously a huge investment but with the $7000 rebate right now, and with the rising cost of oil, my father thinks it is worth doing combined with the insulation.
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Apr 24th, 2009 10:59 AM
#2
From what I have researched getting geothermal for the sole purpose of heating isn't typically the best use of money. It has a very long payback period.
I would imagine it would become more attractive if you were a AC user in the summertime and used the geothermal for that as well, as that would potentially save a large amount of electricity (depending on your usage). However, in most "energy conscious" people I'm sure this would be low, since most wouldn't really crank the AC.
That being said, I've never compared the cost of retrofitting a house with natural gas (from oil) and installing geothermal. I would really think you need to have a detailed cost comparision of the two from people who install them. If you find you're still needing a secondary source of heating with the geothermal that may drive the cost too high, as you are now maintaining two systems.
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Apr 24th, 2009 12:40 PM
#3
well one is a wood stove so there isn't too much maintenance besides cutting down some trees. The furnace needs to be kept to since that is powering our hot water heater.
Natural Gas line is impossible since the closest gas is (I believe) a couple kilometers down the road.
And there is no AC in the house
We know someone who just finished getting one installed a month ago, he said they think it will pay for itself in years.. altho I think that would be optimistic.
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Apr 24th, 2009 02:29 PM
#4
I have a friend who did several energy efficient renovations to his home in various phases, including going geothermal. He discovered the greatest impact on energy efficiency (measured by return per cost) was windows (by far) and then insulation.
The geothermal did have an impact but not in terms of savings. He calculated it would take over 25 years before his initial investment pays itself off (based on a the 'today' rate he used at the time). Of course, his motive for going geothermal wasn't financial so he didn't mind.
I'm surprised the company suggested the windows would have very little impact in improving your efficiency. Were they renovated recently or are they 150 years old too?
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Apr 24th, 2009 03:49 PM
#5
Newbie
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Apr 24th, 2009 04:52 PM
#6
As others have mentioned the Geothermal option's payback is too long. You can go with a dual fuel system, Gas Furnace & Heat Pump, which can give you some more bang for your buck.
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Apr 24th, 2009 06:05 PM
#7
look for triple layer glazed windows with argon or krypton gas instead of air in between the glazings and with insulated frames.
on an individual level, we look at the payback money wise, but renovation of the home helps to reduce the overall energy consumption and CO2 emissions/global warming issues. so go for it!
Last edited by mitboi; Apr 24th, 2009 at 06:27 PM.
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Apr 24th, 2009 06:18 PM
#8

Originally Posted by
mjl_toronto
I'm surprised the company suggested the windows would have very little impact in improving your efficiency. Were they renovated recently or are they 150 years old too?
Well the report has a list of all things that should be done, and then gives a rating beside it how much it would improve the efficiency.. Insulating the attic and the basement were each 14% improvement.
My parents did replace a bunch of windows a while ago actually. The report said they have 48 windows in the house, and 12 of them should be replaced, but it said replacing the 12 windows would only make a 0.2% improvement.
My dad partly wants to do the geothermal heating on the financial aspect, but he also wants to do it because he is getting tired of cutting so much wood.
My mom said they spent $2000 last year on heating oil, plus they went through tons of wood. And they were still cold in the house. So he wants to reduce oil bill, and reduce the amount of wood he cuts, as well as making the house warmer in the winter.
Although I agree, maybe it would be more wise doing all the other upgrades first, wait this winter, see how it goes, then reevaluate next year.
Last edited by Vladimir; Apr 24th, 2009 at 06:20 PM.
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Apr 27th, 2009 12:44 PM
#9

Originally Posted by
Vladimir
My dad partly wants to do the geothermal heating on the financial aspect, but he also wants to do it because he is getting tired of cutting so much wood.
My mom said they spent $2000 last year on heating oil, plus they went through tons of wood. And they were still cold in the house. So he wants to reduce oil bill, and reduce the amount of wood he cuts, as well as making the house warmer in the winter.
Although I agree, maybe it would be more wise doing all the other upgrades first, wait this winter, see how it goes, then reevaluate next year.
I believe the payback on geothermal heating is much greater in areas that do not have access to natural gas, which is the most popular/efficient method of heating within the city. Most of us are comparing it to gas, or having gas available, which is not going to help you at all.
Your situation will be different than most, and you'll need to do the legwork to determine if it's worth it.
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Apr 29th, 2009 06:21 AM
#10
I have done a lot of research on geothermal and I believe the payback numbers are closer to 7 years for those using furnace oil or propane. And this is using current fuel rates which are at historical lows. Plus, there are many non-financial benefits:
- carbon emission reduction equal to 3-4 cars.
- no combustion, therefore no carbon monoxide to worry about.
- no flammable fuel products
- stable pricing - no worries about skyrocketing fossil fuel prices.
- both heating and cooling from the system
- no bulky, noisy A/C unit
- free domestic hot water in the summer, approximately 40% contribution to hot water heating in the winter.
One of the posters is correct, a properly sized geothermal system will not heat the home 100%. To do so would mean an oversized unit that will not be working to top efficiency. A knowledgeable designer will size your system to handle 90% of your heating. During the very cold days, there is an electric heater in the plenum that kicks in to give you a boost of heat. You don't need your wood or oil furnace to give you this supplemental heat.
One problem is that there are ton of new installers in the business with the recent surge in interest. Most do not have the experience necessary to design these systems. Therefore, they often just guess. This leads to big problems with under or oversized bore fields (the pipes under the ground). These problems lead to big expenses in the future.
Vladimir, if you want more info, PM me. I have written way too long a post already.
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May 6th, 2009 03:34 PM
#11
Just to add to skegoats' post, if you really want to delve into geothermal, go to the ASHRAE website and check out the books and papers available. http://www.ashrae.com
These are not cheap but then neither is a geothermal system. Knowing which questions to ask perspective installation companies can mean the difference between success and failure.
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May 7th, 2009 12:07 AM
#12

Originally Posted by
Vladimir
The report said they have 48 windows in the house, and 12 of them should be replaced, but it said replacing the 12 windows would only make a 0.2% improvement.
You have to remember that windows have the poorest insulating value when compared with real insulation. If you look at the chart (http://en.wikipedia.org/wiki/Insulated_glazing) you will see that a single glazed window has an insulating value of 0.16 m2K/W versus a triple glaze window has a value of 1 m2K/W. That's pretty good until you compare it to a 2x6 wall with R-19 insulation - 2.06 m2K/W. I would hazard to say a wall is much cheaper to do that a triple glazed window and you get twice the insulating value. In addition, the total area which windows take up in a standard house is small compared to how much area the exterior walls take up.
While you are insulating, plug up all of the holes and do a lot of caulking to cut down on drafts. You will find a huge difference in the comfort level once the drafts are taken care of.
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May 11th, 2009 12:17 PM
#13
You have to do all of your insulating, stoping draft leaks, and windows before you size a new heating system (geothermal or oil based furnace). The reason is that you will require a much smaller amount of heat from your new heater after the other renos which will reduce the cost of the system slightly and allow you to put in a properly sized system that will increase your comfort.
With regards to windows, I think your report gives them such a small improvement opportunity becuase the air leakage and current insulation is so poor. If your house was already insulated, you would have received a better improvement from changing the windows.
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May 13th, 2009 11:38 AM
#14
thanks for all the info, my father is still researching it, but it sounds like he will most likely go with geothermal. Once my dad has his mind set on something he does it, if something doesn't interest him you never hear of it again.
He has talked to a few different people, and got quotes from different companies, the quotes are ranging from $19k-24k
Thank you for your post skategoat I agree that payback is going to be a lot faster with an oil furnace. When my grandfather first installed the oil furnace they said they were paying about 50 cents a gallon, last year my parents were paying over $1 a litre, and prices are only going to continue to rise. And like I said previously, he is also getting tired and a little to old to cut so much wood so having that as a intangible benefit also helps his decision. Every company said straight up that there will be no way it can heat the house 100% even getting all the insulation done, just due to the size of the house, but it would heat at least 70%+. So given 2 grand burned in oil last year, would save at least 1.5k/year
Last edited by Vladimir; May 13th, 2009 at 06:35 PM.
Reason: wrong quote figures
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May 18th, 2009 12:53 AM
#15
Jr. Member

for oil furnaces and electric heating replacements, geothermal is the best. $$ up front but cost savings wise, in under 10 years it is paid. Works as an A/C system and hot water heater as well.
I would insulate the house as well in your position
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