Gas or heat pump in Midwest?

[Pete C.]

I'd revise that to "a geothermal heat pump with a correctly sized ground loop" since in stable 55 or so degree soil a properly sized loop will always be able to extract sufficient heat.

[dpb]

The point is that the 55F stable point is below the typical loop burial depth as starters so the ground temperature around the loop will rise/fall slightly w/ the seasons and it also isn't a perfect conductor. Particularly when as a heat sink in the summer, temperatures near the loop in the trench tend to rise.

When we installed the system in TN, it was the first buried ground loop the installer had done (he had been working exclusively in a new subdivision on a lake frontage area where loops were submerged in the lake), so we instrumented the trench in several locations for the information on how it differed as he was soon going to be in an area that the distance to lakefront was going to make it impractical.

Even at 6-ft in a place no more extreme than E TN, the soil temperatures were not constant.

--

[Chris Lewis]

According to Pete C. :

We went through the process of costing out a geothermal. They usually size it such that there will be a couple of days per year where the geothermal _alone_ won't quite cut it, and put supplementary heat in for those days. Also, it keeps you from freezing up if something goes wrong with the HP.

[Chris Lewis]

According to :

If the backup heat on the HP is gas, it will _always_ be cheaper. As long as the gas prices don't overtake electric...

[Doug]

Aye, there's the rub.

Here in Connecticut where the frost line in mid-winter can easily get down 40 to 48 inches, to get to that 55 degree point means burying everything down at least 6 to 8 ft. That's pretty costly and sometimes impossible here in New England with its bedrock and rocky soil. While digging just 48 inches, the code required footing depth, I've had to have 6 foot diameter boulders pulled out on a regular basis. The old joke about farming in New England was that farmers mainly grew stones...

A public school near me thought they'd install a ground source heat pump to replace their oil fired boilers. They eventually gave up on the idea when they discovered that the installation costs were something like 5 times the cost of a conventional boiler replacement and a payback time of 15 to 20 years.

They'd be better off simply putting the money in the bank.

Air to Air heat pumps around here are pretty much useless, at least in terms of cost savings. As my building inspector said bluntly "they aren't worth a damn in New England".

The two electric utility companies that serve most of CT have raised their rates 25 to 40% in just the last 12 months. Thus any alternative is now much better than electric heating or hot water making.

Doug

[Pete C.]

As I said, "55 or so". The soil temp is certainly far more stable than the air temp, and again, a properly sized and installed ground loop will have no issues. The nice thing about the ground loop is that since it's just plastic pipe and the trenching is an easy install method, you can readily calculate the correct loop size and then add 25% as a safety margin since an oversized loop doesn't cause any issues and only costs a bit more tubing and trenching. When I do my system I intend to do just this as well as increase the trench depth some, again with no risk of causing any problems, only adding safety margin.

[Pete C.]

CT is where I'm originally from and I've done plenty of trenching there myself. You just have to bring in the correct equipment to do the job. With the trenched vertical coil installation you don't need a wide trench so you can bring in one of the Vermeer monsters for a day and have your deep trench in no time since they have machines that will trench through granite if needed. Not a cheap machine, but when you only need it for a day...

A school i.e. commercial building vs. residence isn't a real good comparison.

Exactly, which is why geothermal heat pumps are necessary there and most other places for the much greater efficiency due to the much more stable source/sink temperature.

The best alternative is a lot more insulation. Also, I thought electric generation / delivery had been unbundled in CT like most other areas, so you have multiple supplier choices.

[dpb]

Well, what you actually said was "stable 55 or so"... I was simply pointing out it ain't as stable nor as near 55 as all that.

--

[dpb]

Ayup. :) I'd think it would be even farther down than that to get 55F year 'round. That's where the alternative to a well source begins to be potentially attractive if there is a water table.

--

[Cindy Hamilton]

55? Good grief! The frost line hereabouts is nearly 4 feet deep. No wonder nobody talks about geothermal heat pumps around here. You'd have to dig halfway to China to find anything like stable 55. And in my 13 feet of yellow clay, that's no picnic, even for a trencher.

Cindy Hamilton

[Pete C.]

They also do drilled vertical loop configurations which work just about everywhere.

Trust me, your clay would be a picnic for some of the trenchers that are available. Vermeer makes one that will cut something like 12" wide x 10' deep trenches through solid granite. Not something you'll get at your local rental yard, but they are becoming more common, particularly in areas of the northeast that have lots of solid shallow rock.

[Cindy Hamilton]

Considering that it's a long way down to solid anything around here, I doubt there's much call for or availability of that kind of equipment.

Well, I suppose geothermal is fine for those who are interested. I just was amazed about the stable 55 degrees recommendation. I'll stick to forced-air gas heat, hot water, and clothes drying. My electric bill is the same year-round, because what I spend on air-conditioning in the summer is matched by what I spend heating the hot tub (outdoors, albeit well insulated) in the winter.

Cindy Hamilton

[<kjpro]

Not true, it all comes down to current utility cost for ones area. Electric may be cheaper, Gas may be cheaper... Oil may be cheaper... it&#39;s all a guess without utility costs.

[<kjpro]

You should have stopped here...

[<kjpro]

If he&#39;s such a super tech... Why are you not asking him your questions?

[<kjpro]

True, as most people call the other system by the name Geothermal. Most people don&#39;t understand that both are virtually the same other than the source for heating/cooling.

[Doug]

Yes, rates have been unbundled to no good effect. Remember what happened in California?

The only ones that have seen any benefit have been large commercial users that have a better bargaining position.

Residential users have been able to access second tier suppliers who offer a 5% discount on generation rates, but nothing off on distribution rates.

Deregulation has been a failure around here....

Even the legislators are now complaining that they were sold a bill of goods.

Electric deregulation only works if there is an ample competitive supply.There isn&#39;t. Generating and distribution capacities are tight in most parts of the country.

Doug

[Pete C.]

California didn&#39;t actually deregulate, they tried to make the suppliers eat varying wholesale prices while capping the retail price. It was a typical CA scam and they ended up paying the price for it. No comparison to states that actually did unbundle / deregulate.

It seems to be working fine here in TX, where I have plenty of supplier options.

I wouldn&#39;t expect anything off distribution rates since those costs are pretty fixed and indeed need to increase most likely to fund the long overdue overhaul of the grid. The generation costs are the variable ones with different generation sources, fuel costs, etc.

Probably needs to be reviewed and compared with states where it&#39;s worked ok to see what&#39;s different and what needs to change.

That&#39;s what happens when the only listen to the lobbyists and don&#39;t actually do their job and research a bit.

I&#39;ve got quite a few suppliers available to me here in TX with varying rates. No dramatic differences in rates, but wouldn&#39;t expect anything too dramatic.

[Clark]

wrote in news:7d890$470eaf0e$9440c41e$5982 @STARBAND.NET:

Another negative and abusive post from kj the dancing monkey boi.

What part of: "as long as the gas prices don&#39;t overtake electric" do you not understand? Clearly the poster understands utility pricing and the thermodynamic cost of generating electricity in the majority of the country. Clearly you don&#39;t understand much of anything.

[Clark]

wrote in news:da306$470eaf75$9440c41e$6016 @STARBAND.NET:

As usual kj offers nothing. Fact is that gas is cheaper than electricity in most of the US markets.