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View Full Version : Geothermal Heat Pump in Southern Maryland


SamSpade
01-13-2009, 08:42 AM
I've been reading about these since - well, a long time. Ever since I first heard of them. If you already have a heat pump, you've probably wondered how come it sucks so bad in extreme weather - you know, when you actually NEED it to do something. And then you realize - I am trying to suck heat out of freezing cold air, or pump heat out of my house into blistering heat. The temperature differential makes it pointless, the worse it gets.

Geothermal makes sense - make the heat exchange take place WAY underground, where the temperature doesn't change much - so your heat pump isn't working overtime.

What do you know about installation costs down here, and what kinds of installations work (open loop, closed loop etc.). Since most of us have well water, I would guess - maybe? - couldn't you just run your coils straight down the well?

GWguy
01-13-2009, 08:48 AM
You might want to check this out:
The Baltimore Convention Center (http://www.bccenter.org/eventDetail.php?id=102)

I seem to remember one time a few years back, they had a geothermal system vendor.

SamSpade
01-13-2009, 08:56 AM
I know there must be vendors all over. Even Trane has their own line of geothermals, and the federal government has been trying to push this. To my knowledge, the fed offers up to a 2k tax credit, and I think Maryland has up to a 3k *grant* for it (although, not surprisingly, they've exhausted all the grant money for the year - there's a waiting list - and they have LESS money for 2009 than they did for 2008).

The one that really piqued my interest is one from WaterFurnace, though.

I've read testimonies claiming as much as 40% drop in heating costs.

It just seems to me that the biggest cost is the placing of the coils, because you have to do so much digging. Why can't you just use your well?

It also occurred to me that I already possess a great heat sink - a swimming pool. Hasn't anyone figured out how to use a swimming pool to heat/cool your home?

migtig
01-13-2009, 08:56 AM
I know of this being used, but not here in MD.

It's usually in areas with a geothermal vent. Do we have one in SoMd? I'm not sure of the make-up of our strata.

Anyway, they do sell the heat pumps online, but I think you need a professional to install it. I did a search on energystar and there isn't anybody within 200 miles. After that I stopped looking. :shrug:

Geothermal Heat Pumps : ENERGY STAR (http://www.energystar.gov/index.cfm?c=geo_heat.pr_geo_heat_pumps)

SamSpade
01-13-2009, 09:07 AM
It's usually in areas with a geothermal vent.

That's a different use of geothermal energy. This is just using the ground as the heat exchange, rather than open air. Heat pumps suck, at the extremes, because the thing you're trying to do is less efeective at the extremes - extract heat from cold air, or pump heat into hot air. But if the exchange point is say, a hundred feet underground, where the temp is always about 60 degrees, summer or winter, you get efficient exchange.


I've actually been reading about regions in *CANADA* (which isn't known for their abundance of geothermal vents) where they are running coils into lakes.

GWguy
01-13-2009, 09:08 AM
I know of this being used, but not here in MD.

It's usually in areas with a geothermal vent. Do we have one in SoMd? I'm not sure of the make-up of our strata.

Anyway, they do sell the heat pumps online, but I think you need a professional to install it. I did a search on energystar and there isn't anybody within 200 miles. After that I stopped looking. :shrug:

Geothermal Heat Pumps : ENERGY STAR (http://www.energystar.gov/index.cfm?c=geo_heat.pr_geo_heat_pumps)

My ex-boss had one in Charlotte Hall. Worked very well, but expensive. if I remember right, he didn't sink it deep like a deep well, but it was installed in a pattern not unlike a leech field, maybe about 10-15 foot down, well below the frost line. The soil temp doesn't get any warmer the deeper you go, so there is no need to drive it deep.

BadGirl
01-13-2009, 09:14 AM
I know of one company locally - Patuxent Pump and Well in Hollywood - that does geo-thermal work. Not sure of their exact scope of work, but perhaps they can assist you with what you're looking for.

migtig
01-13-2009, 09:15 AM
That's a different use of geothermal energy. This is just using the ground as the heat exchange, rather than open air. Heat pumps suck, at the extremes, because the thing you're trying to do is less efeective at the extremes - extract heat from cold air, or pump heat into hot air. But if the exchange point is say, a hundred feet underground, where the temp is always about 60 degrees, summer or winter, you get efficient exchange.


I've actually been reading about regions in *CANADA* (which isn't known for their abundance of geothermal vents) where they are running coils into lakes.

Ah. I misunderstood the concept. :huggy:

I'd worry about running it into my well. Doesn't heat in water encourage bacteria growth?

SamSpade
01-13-2009, 09:20 AM
Ah. I misunderstood the concept. :huggy:

I'd worry about running it into my well. Doesn't heat in water encourage bacteria growth?

I think I misread how that kind works. I thought it meant running the coils down the well. What they REALLY do is use the well water itself as the heat exchanger, and some jurisdictions don't allow this, as the constant use can drain an aquifer. Some configurations, the water, once warmed or cooled, goes back into the aquifer, and that can be a source of contamination.

My guess is that Maryland isn't too cool with this idea, since our aquifers are ALWAYS on the brink of exhaustion.

Wouldn't you know it, there's a great Wiki on the subject.

TinaTina
01-13-2009, 09:24 AM
I've been reading about these since - well, a long time. Ever since I first heard of them. If you already have a heat pump, you've probably wondered how come it sucks so bad in extreme weather - you know, when you actually NEED it to do something. And then you realize - I am trying to suck heat out of freezing cold air, or pump heat out of my house into blistering heat. The temperature differential makes it pointless, the worse it gets.

Geothermal makes sense - make the heat exchange take place WAY underground, where the temperature doesn't change much - so your heat pump isn't working overtime.

What do you know about installation costs down here, and what kinds of installations work (open loop, closed loop etc.). Since most of us have well water, I would guess - maybe? - couldn't you just run your coils straight down the well?

I recently sold my house that had a Geothermal system in it. I bought the house from the owner of Great Mills Heating and Air, so when he built the house he obviously had the resources to install the Geothermal system. It was WONDERFUL! My new house has a regular heat pump and the difference in my electric bill is very noticeable. Both houses are about the same size (around 2600 square feet) and both run everything on electric. My electric bill with the Geothermal system was usually about $175 a month. The MOST it ever was, was about $250 a month, and that was during extremely cold or hot months. The electric bill in my new -non geothermal- house was about $370 for the month of December. Same amount of people, same size house - BIG DIFFERENCE in cost! My old house had well water, but I have no clue how the logistics of the system worked with that.

But anyhow, yes it is available in this area. Give Charles Aud a call at Great Mills Heating and Air (301-994-0522) and I'm sure he'd be happy to discuss it with you.

Larry Gude
01-13-2009, 09:29 AM
I've read testimonies claiming as much as 40% drop in heating costs.


Which would be great if you don't factor in the cost of the equipment and installing it. I'll see if I can find something for you, but, if memory serves, the pay back on $.08 kwh electricity is something like 20 years or more in our region.

GWguy
01-13-2009, 09:32 AM
Ah. I misunderstood the concept. :huggy:

I'd worry about running it into my well. Doesn't heat in water encourage bacteria growth?

There is no real "heat". The exchangers that are in the ground simply transfer the available BTU energy to a sealed fluid exchange system. Ground temps are between 55-60*, but the available BTU energy is very high. There is no exchange of fluid between the geothermal system and your ground water, and in the winter, the down-return of fluid is colder than than the ground. In summer, the opposite is true, but the return fluid is still not "hot".

pcjohnnyb
01-13-2009, 09:40 AM
6.5k square foot house

About 10 residents counting landlord and all tenants

$600-800/mo average electric bill using geothermal.

It could easily be double with the amount of TVs, computers, appliances, etc plugged in...but the geothermal heating saves so much on AC/Heat/water

When it wasn't FREEZING outside, the shower could be run on hot for hours...not that I did that often :lol:

If you can manage the installation costs, I'd say that geothermal is totally worth it in the long run.

camily
01-13-2009, 09:46 AM
My husband just explained it to me (he does HVAC) but I started hearing the Peanuts teacher voice. They do sell them here in Waldorf.

Larry Gude
01-13-2009, 09:47 AM
My husband just explained it to me (he does HVAC) but I started hearing the Peanuts teacher voice. They do sell them here in Waldorf.

:lol:

Larry Gude
01-13-2009, 09:53 AM
I'd say that geothermal is totally worth it in the long run.

Right. If it's a economic decision, like florescent light bulbs, the Prius and so forth, it sounds good but it doesn't make sense, not even long term due to maintenance and repairs and replacing pumps and so forth over time.

If it's a feel good decision, sure.

If electricity goes way up and stays there, say it doubles, then, it is a great idea.

This is why the carbon tax and the cap and trade schemes and other artificial economic impediments are necessary; there is no economic justification for gas and electricity to cost enough to justify wind and solar and geothermal in most areas.

pcjohnnyb
01-13-2009, 09:57 AM
Right. If it's a economic decision, like florescent light bulbs, the Prius and so forth, it sounds good but it doesn't make sense, not even long term due to maintenance and repairs and replacing pumps and so forth over time.

I wonder what maintenance/repair costs are, and how often they need done, in comparison to other heat pumps?

Larry Gude
01-13-2009, 10:02 AM
I wonder what maintenance/repair costs are, and how often they need done, in comparison to other heat pumps?

We'll have to see over time. It's not unreasonable for the system to last, relatively maintenance free, for 20 or more years. In my business, pump quality can be fantastic. Some are JUNK. I think the piping is plastic for geo. I imagine there isn't much to maintaining the fluid quality.

Again, as I understand it, there is something like a 20 year payback in this area at stable electric prices in the $.10 kwh range or so. So, you're monthly savings go into paying off the equipment and install. After year 20, you're money ahead absent major repairs or replacements.

What I wonder is what happens if there is significant movement under ground over 20 years, or less, that could damage the piping. I don't know enough to know, but, obviously, that could be a MAJOR cost if you gotta dig it all up and replace it.

pcjohnnyb
01-13-2009, 10:02 AM
I wonder what maintenance/repair costs are, and how often they need done, in comparison to other heat pumps?
Some interesting, albeit possibly biased as it is .org, information.
Geothermal Heat Pumps (http://www.consumerenergycenter.org/home/heating_cooling/geothermal.html)

[snip]
Cost

As a rule of thumb, a geothermal heat pump system costs about $2,500 per ton of capacity. The typically sized home would use a three-ton unit costing roughly $7,500. That initial cost is nearly twice the price of a regular heat pump system that would probably cost about $4,000, with air conditioning.

You have to add the cost of drilling to this total amount. That will depend on whether your system will drill vertically deep underground or will put the loops in a horizontal fashion a shorter distance below ground. The cost of drilling can run anywhere from $10,000 to $30,000

When energy costs are figured in, however, geothermal systems are probably cheaper. If the extra price for the geothermal system is included in an energy efficiency mortgage, the homeowner could have a positive cash flow from the beginning. The extra $3,500 cost of the more efficient system may add $30 per month to each mortgage payment - an amount more than offset by the savings on the homeowner's utility bill.

Added to an already built home, an efficient geothermal system saves enough on utility bills that the investment can be recouped in two to ten years.

Return to Top

Durability

Geothermal heat pumps are durable and require little maintenance. They have fewer mechanical components than other systems, and most of those components are underground, sheltered from the weather. The underground piping used in the system is often guaranteed to last 25 to 50 years and is virtually worry-free. The components inside the house are small and easily accessible for maintenance. Warm and cool air is distributed through ductwork, just as in a regular forced-air system.

Since geothermal systems have no outside condensing units like air conditioners, they are quieter to operate.

Larry Gude
01-13-2009, 10:06 AM
When energy costs are figured in, however, geothermal systems are probably cheaper. If the extra price for the geothermal system is included in an energy efficiency mortgage, the homeowner could have a positive cash flow from the beginning. The extra $3,500 cost of the more efficient system may add $30 per month to each mortgage payment - an amount more than offset by the savings on the homeowner's utility bill.



This does not address the installation as I read it. $30k to install over 30 years is about $180 a month.

pcjohnnyb
01-13-2009, 10:15 AM
This does not address the installation as I read it. $30k to install over 30 years is about $180 a month.

Don't forget tax credit, though, for "going green".

I would probably say that, in my example of a huge house...geothermal heat will pay for itself in a shorter time period, and be a better investment, in comparison to a 2k square foot house...and forget it if you are one of those people that can't stay in one place for many years to come.

It does raise property value as well, as far as I read.

SamSpade
01-13-2009, 10:17 AM
This does not address the installation as I read it. $30k to install over 30 years is about $180 a month.

There's another factor - I will have to replace it with *something*, soon. The first heat pump on the house is already over 20 years old. The second one is over 10 years old. Typical electric bill during the winter is over 500 a month, and it gets *worse* if it gets really cold.

Short answer - I *will* have to replace it anyway. So adding that in the equation, the answer is factor out the cost of a new ordinary system in any event. It's not dead yet, but it's so inefficient, the cost of keeping it is worse. Certainly worse than 180 a month.

Second - there are at least TWO credits available for the upgrade, one federal, one state. 2k from fed, up to 3k from state, although there's a waiting list.

There are also several configurations for installation, and I'm looking into which will give me the most bang for the buck. I'm also considering what the additional costs will be to replace our old beat up wood stove with a decent pellet insert.

There's also no chance in hell I'd finance in a new system without a substantial amount of cash on hand. Say, a good tax rebate check.

pcjohnnyb
01-13-2009, 10:20 AM
This does not address the installation as I read it. $30k to install over 30 years is about $180 a month.

Here is another interesting tidbit: According to the Environmental Protection Agency, geothermal systems are the most energy efficient, cost-effective and environmentally clean heating/cooling systems available. A 1,500 square foot home in Colorado that uses a geothermal heat pump, averages energy costs of $1 a day. This includes all heating, cooling and hot water needs!

But I noticed later on in that page as well, they claim efficiency and cost-effectiveness, but it is based on a $7500 install and conveniently overlook the drilling cost of $10k-30k added to that :lol:

Larry Gude
01-13-2009, 10:23 AM
Don't forget tax credit, though, for "going green".

I would probably say that, in my example of a huge house...geothermal heat will pay for itself in a shorter time period, and be a better investment, in comparison to a 2k square foot house...and forget it if you are one of those people that can't stay in one place for many years to come.

It does raise property value as well, as far as I read.

Those are all factors. There is no doubt that in terms of pure energy usage, it is a good alternative. All I am saying is each factor must be looked at and then added together to make the whole.

One of the things I find maddening about the left is they argue against tax cuts being a good thing time and time and time again, right up until it's something they want and then, viola, tax credits! The GOP does it as well, corporate welfare, ethanol, etc, but they, we tend to be more consistent on tax cuts being a good thing across the board for everybody and not just the pet project of the month.

If you remove the distortion of government intervention in something like this, then the market can function more cleanly and consumers can see for themselves the cost of a heat pump versus geothermal. As it is, the government, if this works, will end up subsidizing heat pump makers as an important part of the economy, just like Detroit! :lol:

Larry Gude
01-13-2009, 10:29 AM
There's another factor - I will have to replace it with *something*, soon. The first heat pump on the house is already over 20 years old. The second one is over 10 years old. Typical electric bill during the winter is over 500 a month, and it gets *worse* if it gets really cold.

Short answer - I *will* have to replace it anyway. So adding that in the equation, the answer is factor out the cost of a new ordinary system in any event. It's not dead yet, but it's so inefficient, the cost of keeping it is worse. Certainly worse than 180 a month.

Second - there are at least TWO credits available for the upgrade, one federal, one state. 2k from fed, up to 3k from state, although there's a waiting list.

There are also several configurations for installation, and I'm looking into which will give me the most bang for the buck. I'm also considering what the additional costs will be to replace our old beat up wood stove with a decent pellet insert.

There's also no chance in hell I'd finance in a new system without a substantial amount of cash on hand. Say, a good tax rebate check.

You sound like a great candidate. I have a 200 year old farm house that I just put a total kick ass central heat and ac electric system in that cost me about $20,000 and it's running well under $200 a month electric bill, average over 18 months since it was installed.

I will cut an arm off if I have to do much work at all working with the government to get some tax credit. Makes me vomit. That's certainly foolish of me, but, I just can't stand being anymore part of government than I have to.

red_explorer
01-13-2009, 11:41 AM
Stay away from Continental in PF. They installed a friend's geothermal heat pump, and after 2 years, and probably 30 service calls, it still isnt right, and his electric bills are through the roof.

jwwb2000
01-13-2009, 03:22 PM
I do believe the CPCS (Chesapeake Public Charter School) has this type of heating

Chain729
01-13-2009, 04:25 PM
We'll have to see over time. It's not unreasonable for the system to last, relatively maintenance free, for 20 or more years. In my business, pump quality can be fantastic. Some are JUNK. I think the piping is plastic for geo. I imagine there isn't much to maintaining the fluid quality.

Again, as I understand it, there is something like a 20 year payback in this area at stable electric prices in the $.10 kwh range or so. So, you're monthly savings go into paying off the equipment and install. After year 20, you're money ahead absent major repairs or replacements.

What I wonder is what happens if there is significant movement under ground over 20 years, or less, that could damage the piping. I don't know enough to know, but, obviously, that could be a MAJOR cost if you gotta dig it all up and replace it.

Because we, Southern Maryland, get electricity so cheap, "payback" is always a problem with any high cost "savings measure."

Larry Gude
01-13-2009, 04:28 PM
Because we, Southern Maryland, get electricity so cheap, "payback" is always a problem with any high cost "savings measure."

What is your $ per kwh down there?

pcjohnnyb
01-13-2009, 04:39 PM
What is your $ per kwh down there?

I think this is the right page :confused:
http://www.pepco.com/_res/documents/md_schedule_r.pdf
It's a .pdf, showing .11, going up to .12 shortly.

GWguy
01-17-2009, 05:17 PM
FWIW - I did go to the Home show in Baltimore, and there were 2 or 3 vendors that were advertising geothermal.

Chain729
01-18-2009, 07:45 PM
What is your $ per kwh down there?

I think this is the right page :confused:
http://www.pepco.com/_res/documents/md_schedule_r.pdf
It's a .pdf, showing .11, going up to .12 shortly.

Yep, close enough. Just checked this month's bill; it's about 11.6.

Bavarian
01-28-2009, 02:53 PM
I had geothermal system installed in new house in Chestnut Ridge in 1995, cost $12K more than air-source. Was installed by Winslow Pump & Well. Problem was that the system they installed did not hold up. First the coils in the upstairs heat exchanger leaked and even though I had been using Winters, they had a good geothermal tech, no longer there. I wound up buying water furnace from Tri-County Aire. Then the cube unit in basement, attached to upstairs, the compressor went, another replacement. A few years later, the compressor for the downstairs unit failed, I had a replacement compressor installed, a few years later, a coil rusted thru and wound up replacing basement unit with new Water Furnace. So, is it cost effective, doesn't seem so. But the comfort level is much higher than air source heat pump had in old house, warmer air.

It also produces hot water.

This is a closed loop system with seven weels drilled and the pipes go up and down. Added water at times, one tech said if leak, just attach a boiler valve to keep topped off.

Can't compare to cost of operation since only had geo-thermal in house.

BTW, SMECO's new load management switch does not work on geo units. Had them out to swap units so as to continue getting credit, tech said since they are so efficient, no switch. Just as well, he wanted to mount it outside. A big plus on geo is that all equipment in the house, no compressor outside, a big plus.

I think it is worth the cost for comfort.

JoeMac
02-28-2009, 09:06 PM
I used to be in the HVAC business. I can clear up a lot of these questions.

Geothermal heat pumps are THE BEST HVAC system that money can buy hands down. Both in longevity and efficiency. I know some people say that they have had problems, this is usually improper installation. All of the equipment made today is pretty good stuff, kind of like autos.

There are several options as far as the geothermal wells or loops go. Wells is actually a misleading term. An open well or a well that pulls water from the aquifer and then dumps it back out somewhere, usually a drainage ditch is illegal in this area. These heat exchangers are closed loop systems that circulate a liquid through them, usually water mixed with methanol to prevent freezing.

The loops that are allowed are:

1. Vertical, usually 200' deep, 1 well per ton of cooling and are about $1,800 each, so if you need a 3 ton system you will need 3 wells, 1/2 tons get rounded up to the next highest ton, these are the most efficient closed loop

2. Horizontal, will need 1000' of pipe per ton, buried about 5-8' deep, costs vary because anyone with a backhoe can install them, not nearly efficient as vertical

3. Slinky, just like it sounds a coil of pipe buried 5-10' down, you will still need 1000' per ton, just much more compact, similar efficiency to the horizontal

4. Pond loop, a system that pulls in water from a drainage pond, circulates through the machine and then dumps it back, efficiency will not rival the vertical loop

The local authorities will not let you put a closed loop in tidal water or pull tidal water and return it so don't waste your time

The pipe used is a thick black pipe, it is a special pipe that can expand and contract a great deal due to the heat transfer. PVC will not work, again don't ask your contractor for PVC it will crack all up underground

I recommend geo to anyone staying in their house longer than 10 years. All of my calculations show about 10 years to be the payback --EXCEPT new construction your payback will be much sooner and it will make only several hundred dollars in your payment.

A general rule of thumb is $6,500 per ton installed, this usually does not include ductwork or loops. So if you needed a 3 ton system, $1,800 per well is $5,400 plus $6,500 times 3 tons of cooling is $19,500 which is $24,000. This is obviously an estimate and the company I worked for was kind of high so I am sure you can beat this.

One final word on how geo's work, the ground stays a constant 55-60. In the summer the unit will remove the heat in your house and dump it in the ground by way of the liquid heat transfer medium in the loops. This works much better than trying to dump heat in 80* plus air.

The winter is just the opposite, the unit will remove heat from the 55-60 degree earth and dump it in your house. This works much better that trying to remove heat from 30* air.

If you have any other questions, shoot. I will be glad to answer any.


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