Pond Boss Forums INTRO Questions & Observations Geothermal Heat Pump

Well, got my first quote last week and the second vendor is supposed to deliver this Friday.

First guy says "we do many pond loops...maybe 10% total". However, I don't see that in the quote, specifically, especially the digging part to get to the pond. ($15500 before REC rebate and tax credit.)

Second guy says "we specialize in horizontal boring" but they'll quote it both ways. He says they do one 200' round-trip bore per ton capacity. Before calcs, his experience leans to 3-4 tons...and EACH bore is $1300, plus $1200 to get into the house. That's $6400...I can't believe pond wouldn't be cheaper and more efficient.


More confused than ever...

When I got my quotes, I thought the same thing...but the pond loops didn't come in cheaper. I even considered ground loops (but didn't want to tear up the yard again). When they give you the quotes ask them for the details --the unit make, model, capacity etc. etc.----you know all the good stuff that they don't want to share with you as they know you're 'shopping'. Mostly, they sub out the pond looop work so I wouldn't be surprised if digging ground they didn't sub that out too). They shouldn't have any 'hidden' costs from you. I was lucky enough to have a sizeable rebate in Indiana that I was able to take advantage of too. Good luck, no regrets going geo here...mine were reputable and stand by their warranty, good people to deal with.

I think it is standard procedure that the loops are put in by someone other than the HVAC guy. My pond loop (3000') is about 200' from the house. The guy installed it for $7000.

Well...it sounds like the hor. boring is at least comparable to the pond loops, price-wize (already know both org's contract out the loop portion). I like the boring thing from the standpoint that it's WAY less area torn up...only about a 8 foot cube near the house, and we can "point" them anywhere I want. Plenty of room here.

The "contract" I received as a first bid isn't very specific...I'll ask for more details if I go with them. I want make/model, as I've been looking at on-line reviews of many. I realize it's not perfect, but at least I can see some weak areas for some units...

...and my REC offers $1650 rebate off the top, plus $300 for the HWH. With Fed tax credit (as long as it meets the criteria...a CONTRACT mandate) that's 30% of the total project cost. About $4800 total, so that gets it down to around $9500. Steep, but I spent $2000 on LP alone this year and Electric avgs $160/month.

Make sure that the HP is optimized for your climate and heating system in ex. forced air or floor heating. In example if there are more AC than heating days the HP should be optimized for such operation and vice versa.

Ladia:

I'm about where you are...maybe 2 hours east. Not sure, but I think heating degree days are more critical that cooling. Am I wrong?

I don't know exactly the design issues but there is a difference in the geothermal HP depending on the purpose such as a pool heating in Florida or heating a house in Canada and anything in between. In other words it is the best to buy it locally.

Ladia,

What is an approximate cost per ton for a system?
I have the room for horizontal loops and excavation tends to be pretty reasonable.
I'm located in SW Pennsylvania.
Did a load calculation on a geo-site. Came up with 200,000 BTU heat load, 112,000 cooling load. It's a big house, built in the 1930's.
This is a potential purchase and I'm figuring I need to do something like this instead of having a huge gas heat bill....

The cheapest heating is insulation. Geothermal heating is currently the second best. You might need two or three large units for such a house and that could add to the expense. Improved insulation could lower required heating capacity for less money not speaking about lower future energy consumption.
I don't remember how much we spent for our system and partial installation cost. We did a lot of work such as AC installation by ourselves and still spent in my estimation 25 to 30000. The 5 kW (about 4 ton) heat pump itself was 5000. We have both floor heating and forced air-cooling and that adds to the expense.
200 000 BTUs that is about $350 in energy cost (with geothermal) at coldest month at rate 0.041/kWh. Direct electric heat would be about 8 times as much.

The H/C contractor was just out here in preparation for a quoting a geothermal system for our home.

We are talking pond loops rather than ground loops. Our soil below the frost line isn’t soil, it is sand and gravel. The contractor said that sand and gravel isn’t very efficient for ground loops and that pond loops would be the way to go for our location.

There a several reasons that we are a considering a geothermal system at this point in time.

* Tax credits
* Electric Coop credits
* Current H/C system is near the age of replacement.
* The cost of LPG is outrageous when you heat at least some of 7 months of year.
* Gail likes backhoe trenches in the back yard.

I think it will be a no-brainer for us with payback in 3-4 years. The quote will tell the story.

You're lucky man, Dwight!

How big is your pond? You need enough water so the geo would have only small effect on the pond environment. I read somewhere you need at least 1ac 6ft deep or equivalent volume for about 4 ton unit.

5 acres, 10 feet average depth,16,300,000 gallons.

Fantastic.

I have a 5 ton Geo. Pond loop installed in 1/2 acre pond max depth about 9-10'. No significant changes in pond temp. compared to similar ponds nearby. Bottom diffuser aeration isn't significantly affecting efficiency but I don't aerate between November and February. Whole house electric bill last month was $100.43. Worst bill was this winter and a little over $300 but the thermostat was set at 74 degrees most of that month 24/7 and temps outside were often below 0. Going off memory, I think the pond loop install was around $1300, about a third the cost of a ground loop in 2003 but I don't think trenchless was available then. I looked at my loop this past winter with my Aquavu while ice fishing and it is still surpisingly clean and the blocks it's sitting on only appear to have sank about an inch. This might have something to do with aeration.

First contractor said "No problem...we can use the pond."

Second contractor (and a third that I've not talked to, but just randomly mentioned to wife) says my pond (1 acre +/-) is "...too small to be efficient..."

Course, the last guy is just an idiot kid I've known for years, and he's just a gopher for one of the main dirt contractors around here.

Whaddaya think? Is 1 acre in SE Iowa too small? Not from what research I've done...but I don't claim to know much about this stuff.

I don't think it has anything to do with efficiency. We heated our house just from a puddle our first season and it wasn't more expensive than when there was more water in the pond. I am just guessing if the pond (volume of water) is too small then the geo might increase/decrease water temperature by few degrees and it could possibly affect the environment in the pond.
See the quote:

In my opinion your pond is big enough.
Assuming theoretical 1ac 6ft deep pond perfectly insulated with no heat loss.
1ac
sguare ft 43560
depth 6
cubic ft 261360
lb of water 16260349
BTU/degR 16260349
48000 BTU unit will increase the temperature by one degree in
339 hours.
Hope it is right.

Matt,
I'm not an expert on HVAC, but I cannot imagine that your one acre pond would be too small to handle 48,000 BTU of heat. I think the heat load would be completely insignificant. Think about it this way, what if you were trying to heat your pond like you would a swimming pool. Do you think this 4 ton system would make a difference?

Why don't you call the equipment manufacturer?

Matt,

WaterFurnace corp. headquarters in Ft. Wayne, IN. has a one acre pond with loops sunk. They heat their entire building with those loops and that building has got to be 100,000 sq ft.

You say my pond's too small??! Them's fightin words!

Today I placed buoys in the area where the pond loops go. The contractor says 6 feet is deep enough. I say 10 feet is where I want them. We are going with the 2 stage variable speed GEO unit.

Great pond.

Thank you.

Sounds like the one contractor would just rather NOT deal with a pond loop. For that, he gets a thumbs down. The first vendor was happy to do pond loops or trenching...made no difference to him, as he contracted it either way.

Wonder how the contracting out affects any performance warranty?

Either way, I'm getting closer...daughter's wedding is 5/9...wife says this (AND my new shop) have to wait til after that, but I did send out for bids on the shop to a contractor this AM...

My system is a GT-PX Two Stage Puron Serioes (pond loops). It has been inplace 14 months. This happened Friday, a HVAC person came, but with the Holidays they won't be back until later to spend about 2-3 hours looking over system. The geo stopped cooling and it was like 83 outside and 78 inside. The HVAC changed the filter (which they were to do sooner but had to order some); the tech wasn't the regular geo tech (that one is off for Holiday) and he tried to say the filter was problem. Now that I think about it he turned system off and then on later and maybe that is why it worked for about 30 minutes. Of course Sat. morning I called them again as I had to shut the unit down and restart about an hour later and it would work again for a couple of hours. It's the weekend continuing and I'm still turning the unit off and on about an hour and restart if house gets hot. Hopefully, the real geo tech will be out Tuesday. Any thoughts as to what might stop the geo from cooling??? Is there some type of valve that would cause this problem...has anyone experienced this problem? Thanks. Dot

I installed a 3.5 ton unit in a pond that is less than 1/4 acre and 12 feet deep. I installed the entire thing myself and my highest bill so far has been $160 on a very cold month.

http://www.geothermaldiy.com/