Conversion to gas? ? ?

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And the cost of the equipment is????
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Edwin Pawlowski wrote:

Substantial, but it's a long term "green" investment that would probably generate revenue from selling emissions credits.
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What credits? It would not cover the cost or needs of our operation let alone allow for selling credits. Many of our products save energy yet we get no credit for anything by doing that either. That brings up another point. Starting later this year (EPA regulations) we must use our boilers to oxidize what would otherwise be a VOC emission so we could not go 100% solar even if it was practical.
That brings up another government mandated folly. We are installing $400,000 in equipment to do this. The EPA says the payback is in 10 years if we run a full capacity 365/24. Fact is, we only need this particular equipment days 6 hours a day to support the rest of the plant. But they still base their figures on 365 because we "could" run 8760 hours a year even thought they'd never issue a permit to do so or we could ever need it. .
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Edwin Pawlowski wrote:

That 6hr/day could align nicely with the 2nd/3rd shift when you'd have to run the fossil fuel boilers anyway. You'd still be cutting some 33% of both your fuel consumption and your emissions. Again, you are the only one saying 100% solar, I have consistently said ~33% solar. What would 33% of your annual oil/gas consumption amount to in $? Probably a hefty chunk of change towards building the daytime solar boiler.
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We spent about 200,000 last year so the savings potential is $66,000. That is assuming you get 33%. I'd guess we'd be closer to 20% considering weather in New England. Sure, that would be a good savings, but what is the equipment cost? You seem to have missed that question. Where does it get installed and what has to be done to the infrastructure for it? What is the heat potential?
Seems to me, if it was that simple and cost effective power plants around the world would be using it.
Now if I have room for molten salt tanks, this may work http://gizmodo.com/362271/280+megawatt-solar-boiler-uses-magnifying+glass-bug+killer-technique
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Edwin Pawlowski wrote:

http://gizmodo.com/362271/280+megawatt-solar-boiler-uses-magnifying+glass-bug+killer-technique I don't know the equipment cost offhand, but tracking down info on the existing commercial solar stem electric plants in CA would provide a wealth of information. Given the relative simplicity of motorized mirrors reflecting the sun onto a collector tower, and lack of exotic technologies, it may be less than you'd think.
As for location, it goes on your existing roof. Indeed if you have A/C units up there to keep your plant comfortable, the shade provided by the reflector array could significantly reduce the A/C cost as well. The solar energy that is absorbed by all roofs is not only wasted, in most cases it is a negative as well.
If we put appropriate solar energy collection devices on our existing rooftops we can make significant gains in reducing demand for other fuels and energy at the points of consumption, reducing demand on energy that must be transported like electricity, gas or oil, as well as without requiring more land to site collectors.
The other hurdle we need to get past is the all too common idea that if you can't replace 100% of your energy needs with RE it isn't worth pursuing at all.
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wrote:

Hi Pete,
This is a critical point and one that causes me endless frustration. When discussing air source heat pumps, the common objection raised is that they can't typically satisfy 100 per cent of the home's space heating demands and for some folks anything less than 100 per cent is completely unacceptable. What they fail to understand is that you don't have to satisfy all demand for it to be **cost-effective**; it's a matter of determining the optimum solution that provides the greatest **net benefit**. So who cares if you require backup or auxiliary heat on the three or four coldest days of the year if, at the end of the day, it has saved you more money than any of the other alternatives.
We're not all engineers and we don't all hold advanced degrees in economics, but if more of us understood (and embraced) the concept of net present value, it would no doubt help us to make better choices.
Cheers, Paul
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"Paul M. Eldridge" wrote:

Ground source heat pumps take care of that problem for the most part.
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wrote:

Hi Pete,
That may be so, but when you compare the economic performance of a high-efficiency air source heat pump to that of its geo-based brethren, the former prevails nine times out of ten and ten times out of ten if you apply the difference in their respective cost towards measures that further reduce the home's space conditioning and DHW requirements.
Admittedly, that's a pretty bold claim but I've run hundreds of different scenarios using various heat loss factors, weather data, utility charges, install costs, discount rates, etc. and in my experience you have to push the assumptions to the far extremes before you can reverse the results. That said, I'm more than willing to be proven wrong if someone can provide me with hard data and I certainly wouldn't object to sharing mine.
Cheers, Paul
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"Paul M. Eldridge" wrote:

Are you comparing the labor intensive old style deep hole or large trench array, or the newer much better and much less labor intensive trenched vertical coil installation?
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wrote:

Hi Pete,
According to the IGSHPA, vertical closed loops are typically more expensive than their horizontal equivalents, as quoted below.
"Horizontal installations are simpler, requiring lower-cost equipment. However, they require longer lengths of pipe due to seasonal variations in soil temperature and moisture content. Since a horizontal heat exchanger is laid out in trenches, a larger area is usually required than for a vertical system. Where land is limited, vertical installations or a compact Slinky horizontal installation can be ideal. If regional soil conditions include extensive hard rock, a vertical installation may be the only available choice. Vertical installations tend to be more expensive due to the increased cost of drilling versus trenching, but since the heat exchanger is buried deeper than with a horizontal system, vertical systems are usually more efficient and can get by with less total pipe."
Source: http://www.igshpa.okstate.edu/geothermal/faq.htm
Are you referring to something other than what is described above and, if so, can you point me to some online references?
FWIW, I was told by a HVAC contractor based in Moncton, New Brunswick that a typical 3-ton GSHP installation (new construction) runs in the range of $25,000.00 for horizontal closed loop and $30,000.00 for vertical (CDN). Does that more or less jive with your figures?
Cheers, Paul
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"Paul M. Eldridge" wrote:

Yes, something quite different than the two earlier techniques. I'm not sure of references, but for the trenched vertical coil method you cut a fairly narrow (~6" wide) trench something around 8' deep with a big ditch witch and then take the plastic tubing coil and stretch it out sideways so the coils of tube overlap at modest intervals and place the coil in the trench. You then back fill and you're done. Far less labor intensive then drilling holes or digging a big grid of trenches to put single tube runs in. What they found was that the soil was such a good thermal mass that you didn't need to cover nearly as much physical area. This newer installation method takes perhaps 2 hrs to instal vs. all day. Otherwise, it's the same tubing and same equipment, just a lot less installation labor.
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wrote:

Hi Pete,
Thanks for the clarification. I hadn't heard of this technique before so I appreciate you taking the time to describe it to me.
From what I understand, the cost of a ground source heat pump is typically two to three times that of a conventional air source system so if, for argument sake, we peg the cost of our standard system at $7.5K the equivalent GSHP would be $15K or more. Obviously, the exact cost of either system would depend upon a host of factors, but for now I'm going to assume the premium runs in the range of $7,500.00.
As a quick, back-of-the-envelope exercise, an average new home with a space heating demand of 15,000 kWh/year, if equipped with an air-source heat pump (8.5 HSPF/Zone 4) would use roughly 6,000 kWh/year. That same home heated by a GSHP (seasonal COP of 3.75) might come in closer to 4,000 kWh/year. The difference of 2,000 kWh at $0.12 per kWh works out to be $240.00 a year; we might reasonably assume DHW and air conditioning savings kick in another $360.00, in which case our combined savings total $600.00/year -- on the other hand, an air source heat pump with a desuperheater might claw that back to less than $400.00. Nonetheless, if we assume an incremental savings of $600.00, the simple payback here is 12.5 years, with various cash discount rates and utility rate assumptions moving the exact position one or more years in either direction. If the breakeven point, as in this example, is more than ten years, it's fair to say your money would be better spent elsewhere; for a lot of consumers, even a five year breakeven point is a dicey proposition.
Again, these are rough numbers and we can fine-tune them further, but I wanted you to understand my base assumptions.
Cheers, Paul
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"Paul M. Eldridge" wrote:

Interesting. How do you figure that would work out in North Texas (north of Dallas) where there is a lot of A/C load in 100 degree weather and a surprising amount of heating demand in the winter as well? Another non monetary factor to consider is the lack of an outdoor unit with a somewhat noisy fan, and the need to clean it regularly of dirt, pollen, leaves, etc. This is of particular interest since I expect to replace the full HVAC here, probably next year. I also expect to be here quite a few years longer.
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wrote:

Hi Pete,
I can explore this in more detail later on when time permits, if you so wish, but right now it's getting late and I'll soon have to call it a night.
Anyway, in terms of operating performance, SEER ratings are suppose to be reasonably representative of what we can be expect to encounter over the course of the entire cooling season. However, if it is helpful, EER is based on steady-state operation at a 95F ambient temperature (not far from the 100F mark you mention). To get a rough sense of how these two numbers compare, you can convert SEER to EER by multiplying the former by either 0.9 (relatively low humidity) or 0.8 (high humidity). So, if we assume you live in a hot and humid area, an ultra high efficiency heat pump with a 21 SEER rating would have an EER of 16.8 and a high efficiency model with an 18 SEER rating would have an EER of 14.4. To then convert EER to COP -- a more useful measure when comparing these products to GSHPs -- take this second number and divide it by 3.4. Thus, our 21 SEER unit would have a COP in the range of 4.9 (@ 95F) and the 18 SEER version would clock in at about 4.2. Again, this is a rough approximation, but the results seem to be more or less in line with what we could expect from a typical GSHP.
Your concerns related to noise are hard for me to address. The CAC in my Toronto home is a two-stage high efficiency model and on the low setting the outside compressor is surprisingly quiet (a light and not unobjectionable hum). I don't ever recall it kicking on high so I can't honestly tell you how loud it is when operating at full capacity. I don't believe I had any issues with dirt, leaves or pollen -- I may have washed down the outer cabinet with soap and water once or twice but that's basically it.
A GSHP may very well prove your best choice given your particular needs, utility costs, operating environment and so on -- I really can't say. But I wouldn't automatically rule out a high-efficiency air source heat pump without investigating this option further; these products have really come a long way in recent years. Whatever you ultimately decide, good luck!
Cheers, Paul
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Considering there is about 12" of dirt before you hit miles of granite and fractured limestone where I live, his point is still valid...
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Robert Neville wrote:

You could modify the technique a bit for your area, by digging a 6' wide trench to the ledge, laying the coil in horizontal and then back filling and covering with another foot or two of dirt. Slight grade change, but still no drilling or blasting.
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wrote:

Hi Robert,
Much all of Nova Scotia is the same and in some areas you'd consider yourself damn lucky if you had more than two inches.
Cheers, Paul
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You've again provided nice sounding fluff with no figures. Are we talking $50,000 or $5,000,000 or $50,000,000? We certainly don't have the recources that a utility company has. Just a WAG that cost would put it out of the reach of most of us. This is not quite "off the shelf" equipment or technology so the engineering alone can be tens of thousands of dollars.

No AC in the plant. The cost would put us out of business.

Payback. Unless the investment can show savings quickly, most buyers have no interest. Many people move every few years and they are not interested in 10 year paybacks. I'm surprised that more had not been done with solar over the past 20+ years since the last oil shortage got things rolling. There is also dumb zoning. A fellow in our town was told he had to take down his wind turbine because it was too high.
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Dumb zoning, I like that. That could describe so much more than this thread.
As for being surprised that more hasn't been done with solar over the past 20 years, I'm new to the solar scene but I'm amazed at what has been accomplished in just the past 10. And I'm thinking that the next 10 years are going to be amazing.
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