Hi Deb,

I don't live in MD and can't help you with your calculation of cost. What I can do is give you some information that may help with getting you an answer.

A couple of years ago I did the research on Geo Heat Pumps to install in a new house in PA. I had the first bore hole drilled and the unit installed when the local POA stopped me due to "rules" against drilling into the ground.

What I found was that geothermal heat pumps run at about 400% efficiency rate. When you think about the cost of heating, you have to figure it in terms of how many million BTUs are needed for the heating season. You have a large home and that may change the cost somewhat because all the numbers that I found were on homes of average size. The average home uses between 50 and 150 million BTUs for the season. When calculating the cost of a millon BTUs, you need to know the cost of electricity for each KWH (kilowatt hour). For each kwh you get 3,413 gross BTUs (this is what is input to the system). At 400% efficiency, that means you get a net of 13,652 BTUs per KWH. At the average electric rate of $0.09 per KWH that translates to $6.59 per Million BTUs-net.

From that figure you will have to do the math for you home to make the determination. The other thing you want to take into consideration is that the cost of A/C is way reduced because you are taking the cool energy from underground and inserting it into the system and sending it into the house. The cost of A/C is lower since the system doesn't have to work as hard to cool the house since it isn't using the inside hot air. The same holds true for winter heating, you are starting with 55 degree energy from underground and heating that to the temp you set and therefore not starting with outside temps of much less.

Lots of benefits to this system. I still would install it in a heartbeat given the opportunity. The initial cost is high but the payback period is relatively short given the efficiency of the system.

Good Luck!

Re: modern1

You'll heat your home for about 25% of your current cost and save about 45% on your A/C - for as long as you own your home!

"Would it really be a smart investment?"
Would it really be a smart investment not to?

SR

Deb:

I live in Abingdon, Harford County, in an all-electric home. 1700 sq-ft split-foyer, built in 1986.

In June '07, I replaced a fully functional 21 year-old 7 SEER Trane air source heat pump with a new 14 SEER, 12 EER system. I combatted a 72% rise in BGE electric rates (thanks to de-regulation without competition) with a 40% increase in efficiency with the new heat pump.

I don't have any geothermal info, but here is the cost of 1 million btus using an air source heat pump verus oil:

Heat pump (electricity at 13.5 cents per kw-hr, outdoor temp = 35F, COP = 3.25):
(1,000,000 / 3413) x .135 / 3.25
= $12.17

Oil at $3.25 per gallon, 80% efficient furnace:
(1,000,000 / 139,000) x 3.25 / .8
= $29.22

The heat pump costs 240% less to run than oil.

Our climate is perfect for a heat pump.

A co-worker of mine installed a new heat pump and kept his old oil furnace as back-up/auxillary heat for the heat pump. He cut is winter oil consumption way back by doing this plus got new high-efficient air conditioning for the summer. It is certainly something that you should consider.

Best to you.

Deb,

One other thing to consider with the GHP, by adding a "desuperheater" to the unit you can get your hot water for free in the summer cooling months as the heat removed from the house is used to heat the water. In the winter the cost of hot water is reduced by about 50%.

Let us know what you decide.

Best regards...

There are a lot of considerations. SR favors a DX system, which is something I know nothing about. But as far as conventional systems such as Climatemaster or Waterfurnace one chooses between open loop or closed loop.

in another thread a poster stated that the open loop was preferable, but I'm not at all sure of that. Our own experience with an open loop is that the amount we spend to pump water from a well cuts into the savings from the heatpump. On the other hand, the alternative would have been much more drilling and the upfront cost would have been prohibitive.

Open loops are said to perform best when there is an artesian well or all weather spring available to use as a water source.

Closed loop systems require surprisingly little energy to circulate, but the amount of trenching dug can be pretty scary too.

One other thing to comment on and then I'll shut up: Art states what I thought to be the case, that the desuperheater provides hot water only when you are using the air conditioner. But I was told by the technician who installed our system that it gets its heat directly from the high pressure side of the heatpump, and you'll have hot water whenever you use the system. I can't speak to that. I hope somebody else can.

Hope this isn't too confusing!

Thanks,

Mark

Mark,

Perhaps I wasn't clear... Yes you get hot water any time you use the system. The hot water is free during the cooling season and cost about half the normal during the heating season.

We had chosen Waterfurnace for our house. We loved the system ... not the cost. We were planning to use the closed loop version. Our house sits atop a stone mountain in PA and the drilling cost was HIGH. We required 3 bores at 309' each. Each bore was $2700. The alternative (which we had to settle for when the POA refused to let us complete the project) was a standard 16 SEER dual stage HP.

Regards,
Art

Re: Art

Who is 'POA' & what are the 'rules' against drilling into the ground that couldn't be resolved?

Steve

Steve,

The POA = Property Owners Association.

The house is located in a PA "gated" community. The POA a.k.a. The Commuity Association has a book of rules and regulations that must be adhered too by all property owners. This is agreed to when you purchase land in the community. The rule that we ran afoul of is one that is very vague, to wit "no property owner wells of any type". When we installed the GHP we had to have three bore holes drilled. The community called them "wells" and shut us down and assesed us a $2000 fine for breaking the rules. They also made us grout the bore hole. We had to abandon the GHP and purchase a new HVAC system or we would not be allowed to complete construction or obtain a CO. There was no recourse for us. We consulted a lawyer and he indicated that any lawsuit would be tossed by PA courts since this was a private community. Long story short, we lost about 20K on the project. That was nearly three years ago. That wasn't the end of the bad news... last June a lightning strike set the house on fire and destroyed the house. We are now in the process of rebuilding. We love the community but hate the POA. Working from within to dump all of the board members. This will be a daunting task since they "in-breed" and it may take a wooden stake in the heart to get rid of them.

Best,
Art

Good Luck, Art, and thanks for your reply. I hope you are successful.

Best,

Mark

Re: Art

"... last June a lightning strike set the house on fire and destroyed the house."

Art, I would have taken this as not just an act of G-d  but as a message (and a blessing) directly from G-d to me to get the hell out of there and a pox on ALL their houses! Then IÂd collect the insurance money, salt the land and move to a more enlightened community where there is no POA and install my geothermal heat pump.

ÂBut thatÂs just me.

Steve

I am installing a ground source heat pump (wells) in my house under construction in North Carolina. We got the money now to make things as efficient as we can and we figure energy prices are unlikely to get substantially cheaper. The system will use the Water Furnace heat pumps feeding both the radiant floor tubing as well as a forced air heat/ac.

The wells need to be grouted and capped anyhow even if operational. You don't want crud getting down into the water table. Already had to "educate" the county on this one.

re: Ron
I would be interested in knowing what of the NC mtns your are building. I'm starting contruction in the Brevard/Asheville area and am looking for a contractor well versed in the WaterFurnace.
Scott

Thanks for all your responses and support. I'm in the process of getting a load calculation done for my house. I found two contractors who will soon be providing me estimates for conversion from oil to geothermal - CBM Mechanical & Harvey Hottel Mechanical. Does anyone else have a recommendation for an experience geothermal contractor who can design and build the system and will service Howard County, MD?

Thanks again -
Deborah

Deborah,

The best advice I can offer regarding a Geothermal contractor is to locate a "certified" contractor throught the IGSHPA - International Ground Source Heat Pump Association. The web site is posted below. Good luck!

Here is a link that might be useful: IGSHPA - Directory

Thanks Art! One of my contractors - Harvey Hottel Mechanical - is certified. I'll keep my fingers crossed and see what happens...

Deborah