# My experience with Geothermal!



## sevenmmm (Mar 1, 2011)

So-called geothermal!

Geothermal is a system that utilizes heat from ground temperatures that are above 100 degrees. What most people term a geothermal system is actually a "heat pump". 

All of the systems that failed to live up to expectations were those that utilized very long ground loops to transfer the temperature to the circulating fluid - normally associated with dry soil. The longer the loop the higher the head pressure. The higher the head pressure the larger the pump needed. The larger the pump the more electrical usage required.

There is an older couple near me that had me come over to price a photovoltaic system to produce electricity to power the pump. She had 3 years of utility bills without the heat pump and 2 years with. Natural gas usage was down exactly 60%, as advertised, but her electric bill was exactly 60% higher. 20 grand spent with no saving, and now relying on a dirty fuel source.

This was for home heating.

Having very wet soil or a pond could reduce the pump costs, but the best heat pump situation is using water from a strong flowing artesian well. 

No pump costs!


----------



## Harry Chickpea (Dec 19, 2008)

"Geothermal is a system that utilizes heat from ground temperatures that are above 100 degrees. What most people term a geothermal system is actually a "heat pump". "

Uhhhh... NO.


----------



## sevenmmm (Mar 1, 2011)

Uhhhhh.... Yes.

http://en.wikipedia.org/wiki/Geothermal_heating


----------



## sevenmmm (Mar 1, 2011)

The issue at hand is geothermal heating versus a heat pump. 

Geothermal heating does not need a heat pump to be effective...


----------



## ||Downhome|| (Jan 12, 2009)

OK so if its not Geothermal where is the heat pump extracting the heat from?

it is Geothermal. 

read the link you posted.

I think the the issue at hand is more efficiency of different geothermal systems.


----------



## Harry Chickpea (Dec 19, 2008)

The reason I said no is that anything above absolute zero contains heat. Geothermal is NOT limited to ground temps over 100 degrees, as the 55 degree temp in the article you cite agrees. Geothermal simply means ground heat. As for relative efficiencies and so on, you may be 100% correct in that situation. Sites vary.


----------



## sevenmmm (Mar 1, 2011)

||Downhome|| said:


> OK so if its not Geothermal where is the heat pump extracting the heat from?
> 
> it is Geothermal.
> 
> ...


I read it.

Geothermal heating is quite different from using a "geothermal" heat pump. Everytime I read an advertisement by a heating company extolling the heat pump they never distinguish the differences. 

In my opinion, this is a disingenuous play on a hot springs geyser... 

I stand firmly behind my posting.


----------



## Jhn56 (Oct 11, 2011)

Howdy all, first ime poster here, nice site!

7mmm, Sounds as if you happened across a really ---- poor design, drawn up on napkins while sitting in the local pub. 

Judging by the title of the post, I presume this is your only geothermal experience?

I built my new home, one year ago, last month. I installed a waterfunace, closed loop water to air type system. The home is 2000 sf, and it is entirely electric. We keep the thermostat @ 72* throughout the winter months and 70* in summer. Having said that, I just recently sat down and averaged my 1st years electric bill, which is $161/ month.


----------



## artificer (Feb 26, 2007)

It sounds like you don't agree with a badly designed heat pump loop being called geothermal. Break it down... geo and thermal. heat from the ground. If the heat is low quality, you need a heat pump to use it. Extremely few people have hot springs as a source of heat or other higher quality heat sources. Even your article mentions ground source heat pumps.

If the head pressure is as high as you think it is, then the system is badly designed. You don't use one long pipe to run all of the liquid/water. You have several/many parallel loops to maximize heat transfer surface area, while still maintaining low pumping losses.

The argument is useless anyways, since you don't give any numbers. Does the electric power cost as much as last years gas? I can see a situation where gas usage is reduced by 60% and electric increases by 60%, but since the electric cost was only 10% of the gas cost, you're still ahead as far as money for heating goes.

A properly designed geothermal heat pump system will have a COP of at least 2, if not more. If gas an electric cost roughly the same on a BTU basis, then you can get great savings with the heat pump... if its designed properly. Historically, gas has been cheaper than electricity, so you first have to overcome the savings with gas, and then get additional savings due to the heat pump. It all comes down to proper design.

Michael


----------



## sevenmmm (Mar 1, 2011)

I still have the bills, the gas cost went down 60% while the electrical cost went up an amount to cover the 60% savings. The electrical cost equaled out the gas savings for no savings at all. 

Now, I will admit this was the worse case scenario, but in every case, the electrical cost rose significantly once the HEAT PUMP was installed. 

Here is a normal conversation with people that approached me while doing a show promoting solar heating:

"We installed geothermal a few years back and are looking for a way to make solar electricity for it".

So I would ask, "How much more electricity are you using"? 

"I am not sure, but my electrical bill went to $400 a month".

My follow up, "Did the contractor who installed your system give you a heads up your electrical costs will increase"?

"I don't think so". 

I would then ask, "Maybe there is something wrong with the system, you should call the contractor".

"He has been over a number times and can't find a thing wrong with it". In some cases they said the contractor won't return their calls anymore.

I would tell them they need to know how much electricity they need so a photovoltaic system can be sized for the job.

Then I explained to these saps why they have this problem. How the heat gets transferred to the HEAT PUMP fluid through that long undergound loop, spending a little time on head pressure and the electricity required to operate the pump. I tell them the system works fine in moderate temperatures of spring and fall, but when the house is calling for the tremendous amount of BTUs during the coldest months, or the tremendous amount of cooling in the summer, most always, the HEAT PUMP has to work 24 hours a day to keep up. Most of these systems are designed with price in mind, so most of these systems require another heat/cooling source to keep the house a constant temperature. You know Americans, they want perfection!

So anyway, I further explain that as the system is pulling heat from the ground, now read this carefully, they are also PULLING HEAT FROM THE GROUND! That means the ground surrounding the loop becomes colder. Guess what? The system has to circulate ever more to make gains. Until the ground surrounding is nearly frozen - if the house is a McMansion with a too short of loop - not much happens then.

At this point I break their hearts by telling them they made the wrong decision as their area is not one that suits HEAT PUMPS very well. 

If anyone wants to read about it, I have a gory story about a well water system too.

Oh, and if you know someone with a HEAT PUMP, ask them for their electrical bills before and after. Be forewarned, this is a touchy subject.


----------



## sevenmmm (Mar 1, 2011)

Jhn56 said:


> Howdy all, first ime poster here, nice site!
> 
> 7mmm, Sounds as if you happened across a really ---- poor design, drawn up on napkins while sitting in the local pub.
> 
> ...


Where are you located? How much was your electric bill before you installed the system? Is this your only heating and cooling source?

Oh, and you should know I sat at a booth fielding all kinds of complaints from people having installed a HEAT PUMP. Sure, there are a few good stories too.


----------



## sevenmmm (Mar 1, 2011)

Oh, and back to the gas cost vs electric cost scenario. When I was most active the price to buy natural gas was much higher than it is today. Also, electrical costs were lower, then than now. So all those HEAT PUMPS are really screwing their owners over big time, those that were put in place a few years ago. 

Plus, or rather a big minus, they are now using dirtier fuel (most electricity is produced from burning coal, or worse, nuclear) contributing deadly toxins negatively into the atmosphere.


----------



## Jhn56 (Oct 11, 2011)

7mmm, I can't help but think you are confusing an air source heat pump with a geothermal ground source heat pump. My system consists of 6 - 1000' ground loops, filled with a glycol based solution, approx. 6' deep. The waterfurnace geothermal heat pump is a 2-1/2 ton model, equipped with a desuperheater, which provides me with hot water as a byproduct while in the air conditioning mode.

http://www.energysavers.gov/your_home/space_heating_cooling/index.cfm/mytopic=12640

I live in NJ, the winters aren't severe, but it is cold, I would estimate avg Winter temps in my area @ approx. 35*, the summers are hot and humid. In the spring, I literally went from heat to air conditioning as we couldn't open all the windows due to the amount of pollen drift out here in the sticks.

My previous electric bills in a different home of approx. the same size averaged over $375/mo. My old home, which I also built, back in 1990, was typical 2x4 framing, had the older Andersen 200 series windows, r-30/r13 overlay (r-43 ceilings), 90+ gas forced hot air heat, etc...a better than avg home, in it's day.

My new home, I built with 2x6 framing, high density r-21 insulation ext walls with an additional 1" r-5 foil faced foam. Ceilings were insulated using r-38 high density with an additional r-13 unfaced overlay (r-51). Andersen 400 series windows/doors etc...is entirely electric.

My last home was a 2-story, this one a sprawling ranch. This is my only source of heat/air, no oil, gas, propane, or wood burning.


----------



## Jhn56 (Oct 11, 2011)

I am really interested in what other experiences you have with "geothermal", if any? Tell me a story of a system, which was well designed and installed, I think the readers here deserve to hear the other side of the coin. There are over 50,000 of these units being installed annually, they can't be all bad, I have one that works perfectly!


----------



## sevenmmm (Mar 1, 2011)

Yeah, you have a low heat load and the area temperatures are moderate. That could explain the differences. What diameter is the ground loop?

How much did this system cost?


----------



## Jhn56 (Oct 11, 2011)

The ground loops are 1" polypropylene rated for 50 years, the out of pocket cost to me after incentives and rebates was 17K. This is beginning to feel like a one way conversation as I've asked in every reply, what other experiences you've had with "geothermal". Please read my posts again, reciprocate, Thanks


----------



## artificer (Feb 26, 2007)

sevenmmm said:


> Now, I will admit this was the worse case scenario, but in every case, the electrical cost rose significantly once the HEAT PUMP was installed.


Unless they previously used electric heat, my answer is OF COURSE thats true. Its a no-brainer. When you switch to electric heat, your electric bill is going to increase.




sevenmmm said:


> Most of these systems are designed with price in mind, so most of these systems require another heat/cooling source to keep the house a constant temperature. You know Americans, they want perfection!


And this sums up the problem. Not a properly designed system, but a system designed for a price point.



sevenmmm said:


> So anyway, I further explain that as the system is pulling heat from the ground, now read this carefully, they are also PULLING HEAT FROM THE GROUND! That means the ground surrounding the loop becomes colder. Guess what? The system has to circulate ever more to make gains. Until the ground surrounding is nearly frozen - if the house is a McMansion with a too short of loop - not much happens then.


Once again you say a poorly designed system isn't working like it should. As for not working in cold climates, how about Alaska, Sweden, and Canada? Take a look at this article titled Ground Source Heat Pumps in Cold Climates. Properly designed and installed systems that work. As for the gory well water system... If it was poorly/under designed, it will not work correctly. Its more a comment on the designer/installer than the whole geothermal/ground source heat pump issue.

I'll say it again... a properly designed system will work as it is supposed to. You may not be able to afford it, and it may never pay for itself, but it will work properly.

Michael


----------



## sevenmmm (Mar 1, 2011)

I never typed they didn't work. 

I typed the electrical costs with a ground loop in dry soil is very high, sometimes to the point of equaling out what would otherwise have been the natural gas cost using a conventional heating source.

Using jhn56's house heat load, please compare the natural gas cost using a furnace to heat the house with the electricity necessary to power the HEAT PUMP and related components.

Please also note that electricty is a dirtier fuel source than natgas, and, eletricity is more problematic (such as blackouts) than natgas.


----------



## artificer (Feb 26, 2007)

Your statement "20 grand spent with no saving, and now relying on a dirty fuel source." is basically saying the heat pump is no better than straight electrical heating... it isn't working like it should, if it was properly designed.

I disagree that "the electrical costs with a ground loop in dry soil is very high" with a PROPERLY designed system. The minimum COP should be 2, and should be at least 3 or 4, even during cold winter months. What the people you are refering to have is an IMPROPERLY designed system. A proper design for dry soil may not be economical on a return on investment basis, but as long as the cost of gas is over 1/2 of electricty on a $/btu basis, you will spend less on electricity with the heat pump.

I can't calculate jhn56's heat load, since it hasn't be provided. If you give me the btu's/hour needed, the cost of gas, the cost of electricity, and the efficiency of the gas furnace used, I can give you a fairly decent projection on relative costs.

I keep harping on "properly designed". Unlike electric resistance heating or a gas furnace, the heat sink/source makes a tremendous difference on the operating efficiency. If you use one line for the entire loop, you will have tremendous pumping losses unless you use very $large diameter$ pipe/tubing. If you don't have enough surface area to get over 45degF return temps, your COP will drop. If the person that designs the system doesn't pay attention to local conditions, you end up with a system that doesn't work right.

michael


----------



## Nica (Oct 3, 2009)

We have a geothermal system and love the savings we're getting. Ours works extremely well.


----------



## sevenmmm (Mar 1, 2011)

Please explain away this article:

http://www.greenbuildingadvisor.com...og/ground-source-heat-pumps-don-t-save-energy


----------



## sevenmmm (Mar 1, 2011)

I we need to clear up the geothermal part. Ground based heat pumps actually use energy from the sun, not the Earth:

*Ground source heat pumps are also known as "geothermal heat pumps" although, strictly, the heat does not come from the centre of the Earth, but from the Sun. They are also known by other names, including geoexchange, earth-coupled, earth energy systems. The engineering and scientific communities prefer the terms "geoexchange" or "ground source heat pumps" to avoid confusion with traditional geothermal power, which uses a high temperature heat source to generate electricity.[2] Ground source heat pumps harvest heat absorbed at the Earth's surface from solar energy.*

*Although it is clear what heat pumps do, there is confusion with regard to the terminology and use of the term "geothermal" . "Geothermal" is derived from Greek and means "heat from the Earth" and can properly be used to describe hot rocks, volcanic activity or heat derived from deep in the earth. Confusion arises when the term "geothermal" is also used for marketing reasons to apply to temperatures within the first 100 metres of the surface which closely match the mean annual air temperature at the surface.*

*Economics

Ground source heat pumps are characterized by high capital costs and low operational costs compared to other HVAC systems. Their overall economic benefit depends primarily on the relative costs of electricity and fuels, which are highly variable over time and across the world. Based on recent prices, ground-source heat pumps currently have lower operational costs than any other conventional heating source almost everywhere in the world. Natural gas is the only fuel with competitive operational costs, and only in a handful of countries where it is exceptionally cheap, or where electricity is exceptionally expensive.[4] In general, a homeowner may save anywhere from 20% to 60% annually on utilities by switching from an ordinary system to a ground-source system.[30][31] However, many family size installations are reported to use much more electricity then their owners had expected from advertisements. This is often partly due to bad design or installation: Heat exchange capacity with groundwater is often too small, heating pipes in house floors are often too thin and too few, or heated floors are covered with wooden panels or carpets.*

*Ground-source heat pumps use electricity for heating the house.... If compared to natural gas systems, the payback period can be much longer or non-existent.*

http://en.wikipedia.org/wiki/Geothermal_heat_pump


----------



## sevenmmm (Mar 1, 2011)

Jhn56 said:


> The ground loops are 1" polypropylene rated for 50 years, the out of pocket cost to me after incentives and rebates was 17K. This is beginning to feel like a one way conversation as I've asked in every reply, what other experiences you've had with "geothermal". Please read my posts again, reciprocate, Thanks


You want me to revisit those people who had issued complaints? You want the telephone numbers? 

I am not attempting to personally insult you by wanting to know why your system is working so well. I have not once refuted a single reference you have made. If you reread my above post, you will notice I typed there were also some good stories. If nothing else, you should feel justified by typing good answers. Thank you.

Look, I do not like ground source heat pumps because they use electricity (dirty fuel), and often a lot of electricity. If you like to use electricity, then fine with me.

Oh, and 17k is not a bad price compared to other estimates I have viewed.


----------



## artificer (Feb 26, 2007)

sevenmmm said:


> Please explain away this article:
> 
> http://www.greenbuildingadvisor.com...og/ground-source-heat-pumps-don-t-save-energy


The statement "But, in general, when the electricity used by the pump is added to the picture, the COP probably drops to 3 or lower, which means that heat pumps actually use more fossil fuel than a furnace or boiler" pretty much sums up the explanation. 

He is not arguing that it will cost less, he is arguing that if your electrical power comes from fossil fuels, and if the generation of it is less than 33% efficiency, then you use more fossil fuel. Unless your gas is only 1/3 the cost of electricity you will have a savings with a 3COP system. If the system is badly designed, then you will not see the savings, and will probably be worse off.

Consider Canadian electrical power. They call it "hydro" since a significant portion of their power is hydroelectric. (Canadians correct me if I'm wrong, or if its regional) If they use a heat pump, they are using renewable energy without any fossil fuels.

Here's an example of two different systems. One recommendation I've seen is 800' of heat exchange tubing for each ton of heating. Jhn56's system has 6,000' of tubing for 2-1/2 tons, or 2,400'/ton. Thats 3 times the recommended amount, and his system works well.

Another example is what differences in design makes. Take a 4 ton system. It needs at least 20gpm with a 5degF temp difference to provide the heat needed. 1,000' of 1" pipe will have a 108psi pressure drop. Thats 1.26hp or 945 watts. If you use 70% motor efficiency and 50% pump efficiency, you get 2520 watts of actual power used. This is ridiculous. Use 6 of the 1,000' lines and your pump losses go down to 78 watts. If you use 1-1/2" pipe instead, you go to 292 watts. A 4 ton unit will provide 48,000 btu/hr of heat. This is 14,117 watts of heating. If the COP is 3, it means you're using 4706 watts of power to heat with. With the worst case scenario of 2520 watts of pumping power, you are using 52% more power with the single short line. The 6 lines use only 1.6% more power (and was included in the COP=3 anyway). Pump losses can be very low in a properly designed system.

I can see that you don't like ground source heat pumps, and thats fine. If you don't like them because they don't save money, I would say you've only dealt with poorly designed systems, and you should fine some that work in your area. If you don't like them because they use dirtier fossil fuels, thats an entirely different argument, and it all depends on where your power is coming from. If you don't like that heating with electricity uses a lot of electricity, then I'm sorry.

Michael


----------



## Femur (Nov 29, 2010)

My friends,

I have found this discussion of the true value of heat pumps to be very enlightening. I wonder if you folks who assert that geothermal heat pumps might not be as valuable/efficient as generally perceived could comment on their value/efficiency in *cooling.*

Would a properly installed geothermal system relied on generally for cooling (say in the Texas gulf coast region) be recommended?

thanks


----------



## artificer (Feb 26, 2007)

Femur: You have to do a serious cost/benefit analyse on the system. I don't think you can recoup your money with a ground based cooling system. In Texas you don't need ground sourced system for heating, since you have warm(ish) temperatures. The thousands of dollars needed for the ground loops would be better spent on a cooling tower.

The COP (coefficient of performance... heat out/heat in) gets better when the difference in temperatures is low. If you've ever sprayed water on the condensing/hot coil of an air-conditioner, you'll have seen just how hot it is. The water boils off quickly. If you could decrease the temperature the condensing coil get to, and still gets rid of the heat needed for air conditioning, you would improve the performance of the system. A refrigerant to water heat exchanger and a cooling tower can do this. The problem is added cost and complexity.

A better solution is better insulation. Many southern buildings have minimal insulation compared to northern buildings. If your building has little insulation, you'll find its the best bang for the buck.

Michael


----------



## quietstar (Dec 11, 2002)

Good question Femur, and one that I would like a simple, straightforward response to. From my research experience, Nothern "experts" know little about about ground cooling thermal systems, but talk as if they do...Glen


----------



## sevenmmm (Mar 1, 2011)

artificer said:


> The
> 
> 
> Consider Canadian electrical power. They call it "hydro" since a significant portion of their power is hydroelectric. (Canadians correct me if I'm wrong, or if its regional) If they use a heat pump, they are using renewable energy without any fossil fuels.
> ...


Indeed. But the next step would be to compare the cost of a properly-sized system with other options.


----------



## Ross (May 9, 2002)

My inlaws have a 2 well heat pump here in Ontario. The electric backup does come on in prolonged -20c temps. Still they heat 1600 sq ft for much less than oil and only a bit more than nat gas. If they would add insulation that would save more though.


----------

