Anyone here use a geothermal heat pump?

[charlie_D]

My house heats with geothermal... Sorry, I can't tell you what the bill was prior to installation, it came with the house (one of the things I was looking for in an acreage).

I *can* say that my monthly energy bills have been sitting around the $250 - $300 mark, and that the house is (somehow) using approximately 3000Kwh per month currently. Hard to tell where the leaks are in the summer, but I sure am finding them in the winter! Unfortunately the furnace doesn't run *that* often, so I'm not sure where the rest of the energy is going currently... though I did find a 'hot' outlet and other electrical gear out in the bush when I was wandering around. Hadn't noticed it before because
a) it's about 20ft into the bush on all sides, and
b) it's on the ground; looks like it got knocked over by a tree a decade or so ago, based on the corrosion.

Wonder how many other treasures I'll find now that I can see past the undergrowth?

Anyway, here's a pic of the furnace :



Charlie

[Xringer]

Now that I've seen first hand how well mini-split (ASHP), can pull heat out
of the air, there is no way I would ever think about geothermal..


http://ecorenovator.org/forum/projec...l-project.html

We have been using it in cooling mode this summer and my wife thinks
it's the best thing we have ever purchased..

And it's saved us many gallons of heating oil during the cold weather.

The way I see it, ASHP (Air Source Heat Pump) are pretty much solar/geothermal,
since the air is getting it's warmth from the sun and the ground.
(And all the cars out on Rt-95).

So the heat my Sanyo Mini-split is pulling out of the air, is pretty Geo..

I've been using a ground water heat pump since 1980. I replaced it with a new one about four years ago.

It is open loop, where I have two pickup wells tied to one pump on the north side of the house and two return wells in my back yard. I've had very good luck with mine, though most people I know have problems with open loop ground water heat pumps. Most with open loop water pickup and return systems have mineral deposits build up in their lines. At my place, from about one to two feet down to about 25 feet down is sand, with the top foot or two being organic topsoil. At 25 feet down a hard layer, probably limestone marl, exists. My wells are only 20 feet deep and there are a couple large ponds within 500 feet of my house that may be helping to give me clean groundwater.

[zick]

Originally Posted by AC_Hacker

The high water table would make a trench-type loop field for GSHP very difficult. On the other hand, boreholes would be optimal. Wetter soil makes for better heat transfer.

Regards,

-ACHacker

We built a new house summer 09' and put in a Geothermal unit. We also have a very high water table (Flood zone). When we were building the water table was so high due to previous flooding the years before that just 1' below the surface we hit water!
This put us out of the horizontal loop option. They tried doing horizontal bores but kept hitting rocks.
Finally we had to pay a little extra and put in 5 wells that were 150' feet deep each.
I'm also thinking that having a high water table might be a good thing for Geo and increase efficiency.

I must say that we are very happy with the results. With our old (poorly insulated) small house (<1000sqft) we were paying roughly $75-100/month to heat. Now our new very well insulated (~2800sqft) house it is costly us only about 2x to heat and we even heat it warmer than we used too!

We almost didn't go with the Geo at first due to the cost being right about 30% higher than a HE Gas boiler. But then the Tax credits changed and removed the cap and we got that 30% back after taxes.

[AC_Hacker]

Originally Posted by zick

...it is costly us only about 2x to heat and we even heat it warmer than we used too!...

Perhaps you meant to say, "...only about 0.5x to heat..."?

...or maybe, "...roughly half as much to heat..."?

-AC_Hacker

[zick]

No, I meant 2x (twice as much). So roughly $150-200 for heat.
I guess I consider this good, since my parents house (which is also newer and almost same setup as us but no geo) pay quite a bit more than this to heat.

[AC_Hacker]

Originally Posted by zick

No, I meant 2x (twice as much). So roughly $150-200 for heat.

So sorry, I didn't realize you were comparing two different houses.

I have often seen reports of heating bills being cut in half for the same house, I thought you were making the same statement.

-AC_Hacker

[zick]

No worrries. I realize most people try to compare two systems in the same setup (I.E. House) but we weren't able to do that. Although we would have loved too. Guess I just wanted to share my experience.

I would have loved to say that Geo cut my bills in half. But I guess my thinking is that I'm now heating a house that is 3x in size for only 2x as much and I'm heating it to a higher temp than before too.

[zick]

Now that we have a couple years under our belt, just like to give an update.
So far the system has been working flawlessly with no issues.

Our average bill has been about $112 and the highest was around $190.

Here is roughly our heating/cooling cost for 8 months.


12/10 KHw 1369 Cost $157.435 Avg temp 33F
1/11 KHw 1305 Cost $150.075 Avg temp 22F
2/11 KHw 1660 Cost $190.9 Avg temp 18F
3/11 KHw 950 Cost $109.25 Avg temp 35F
4/11 KHw 747 Cost $85.905 Avg temp 45F
5/11 KHw 369 Cost $42.435 Avg temp 52F
11/11 KHw 315 Cost $36.225 Avg temp 48F
12/11 KHw 1074 Cost $123.51 Avg temp 37F

Average Khw 973.625 Average Cost $111.966875

[Xringer]

Hi Zick,
Are those kwh just what the GSHP is using? (Or the total bill).

I just read out my TED the other day (for ASHP heating). It's at:
http://ecorenovator.org/forum/geothe...html#post19401