Geothermal Heat Pump in Southern Maryland

[SamSpade]

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]

You might want to check this out:
The Baltimore Convention Center

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

 

[SamSpade]

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]

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

 

[SamSpade]

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]

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

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]

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]

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.

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

 

[SamSpade]

Ah. I misunderstood the concept.

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]

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]

...

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]

Ah. I misunderstood the concept.

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".

 

[theArtistFormerlyKnownAs]

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

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

 

[camily]

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]

...

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]

...

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.

 

[theArtistFormerlyKnownAs]

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]

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.

 

[theArtistFormerlyKnownAs]

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

[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.

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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]

...

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.