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joe.ami
Veteran Member
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| 03 Feb 2012 10:02 AM |
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2 feet of snow would be very uncommon in my AO. There are certainly areas where geo doesn't work, but few where elec resistance heat is cheaper to operate than geo or ASHPs.
One must be designed and installed correctly, but the energy banking (need summer heat to prop up winter loads) and other such comments are wives tales. |
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Joe Hardin
www.amicontracting.com
We Dig Comfort!
www.doityourselfgeothermal.com
Dig Your Own Comfort! |
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FBBP
Veteran Member
Posts:1215
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| 03 Feb 2012 11:10 AM |
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doc - cold climate is much more than source temperature. I could probably agree that a competent designer can produce a functional system with 42 º source. But add to the equation minus 32ºc (-26ºf) design temps and an extended heating season and the situation becomes some what clouded. We can expect lingering snow every month of the year. (thankfully not every year) Even when we have day time temps of high twenties or low thirties night time temps are always below 17ºc. Usual night time temps are low teens or upper single digits. Most heating systems seldom have more than a 45 day break.
doc - I hope you will forgive me if I say I remain a bit skeptical that a system can be designed for effective use in this climate and I will allow that it might be done by a competent Designer.
Lets suppose that it could be done, with the extra cost of the larger field (horizontal or vertical (not talking water source)) and the extra power requirements for the pumps for the larger field, I don't believe the numbers could work compared to any natural gas heating system in the local market. If you lucked out and hit a substantial aquifer in a bore field it might up the stakes a bit. But by and large I would suggest this is not gshp area.
There is no doubt that Sweden has a high per cap ratio of heat pumps. Further study show most are in the south Maritime region. Out door design temp for Stockholm appears to be minus 17ºc which is a bit different than -32. Really just a cool climate. Incidentally McQuary lists gwt for Stockholm at 47ºf.
Joe - The Alaskan study and all the Canadian studies must have had at least one old wife on board than eh? ;-) |
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southline
New Member
Posts:20
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| 03 Feb 2012 11:22 AM |
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Posted By FBBP on 02 Feb 2012 02:43 PM
Joe - I agree completely that the source is passive solar. I don't understand how January sunshine hitting two feet of snow on a minus 25ºf day will effect the 18 to 36" of frozen soil laying over top the 6' deep slinky.
This is why geo works so well on a minus 25F day.. or night. :) Adam |
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docjenser
Veteran Member
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| 03 Feb 2012 06:47 PM |
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Posted By FBBP on 03 Feb 2012 11:10 AM
doc - cold climate is much more than source temperature. I could probably agree that a competent designer can produce a functional system with 42 º source. But add to the equation minus 32ºc (-26ºf) design temps and an extended heating season and the situation becomes some what clouded. We can expect lingering snow every month of the year. (thankfully not every year) Even when we have day time temps of high twenties or low thirties night time temps are always below 17ºc. Usual night time temps are low teens or upper single digits. Most heating systems seldom have more than a 45 day break.
doc - I hope you will forgive me if I say I remain a bit skeptical that a system can be designed for effective use in this climate and I will allow that it might be done by a competent Designer.
Lets suppose that it could be done, with the extra cost of the larger field (horizontal or vertical (not talking water source)) and the extra power requirements for the pumps for the larger field, I don't believe the numbers could work compared to any natural gas heating system in the local market. If you lucked out and hit a substantial aquifer in a bore field it might up the stakes a bit. But by and large I would suggest this is not gshp area.
There is no doubt that Sweden has a high per cap ratio of heat pumps. Further study show most are in the south Maritime region. Out door design temp for Stockholm appears to be minus 17ºc which is a bit different than -32. Really just a cool climate. Incidentally McQuary lists gwt for Stockholm at 47ºf.
Joe - The Alaskan study and all the Canadian studies must have had at least one old wife on board than eh? ;-)
Trust me, I realize that cold climate is different. I lived in Minnesota for 9 years.
At the end of the day, 2 things are of primary importance: Peak capacity of the heatpump to cover enough load so you are not heating too much with electrical resistance, and loop capacity,to ensure that you alway deliver water to the heatpump within its high efficiency operating range
Well, lets run the numbers. I just did a Manual J for a 2400 sqf new built house in western New York, and it was 41 KBTU/H at 0F outside and 70F inside. The same house at -30F outside design temp would have a heatloss of 58 KBTU/H, for a 100F delta T between inside and outside.
So in Western New York, this would be a 3 ton system (41 KBTU/H heatloss) with a 400FT borehole (assuming 1.25" pipe) in order to keep the the EWT at or above 30F.
In Calgary, you need a 5 ton heatpump (59 KBTU/H heatloss) and at the 43F ground temp which the software gives me for Calgary you would need about 995ft of bore hole to keep the EWT at or above 30F (again, 1.25" pipe in average rock, 1.4 conductivity).
So yes, the heatpump is about 66% larger, and the loopfield is about 150% larger to carry the load at the lower ground temp, but the efficiency would be pretty much the same, the average and min EWT are the same.
But you would also need more gas consumption, and the cost of operation, e.g. the $/BTU does not change. Yes, the upfront is higher, but given the increased BTU usage in Calgary, the potential savings are also higher. Yes, you would need 2 circulation pumps for a 5 ton HP, instead of one for a 3 ton, so add $90/year for more pumping power.
How much more upfront? A turnkey system with 2 tanks, DSH, and vertical loop runs about $25K in WNY. Now, a 5 ton with a 1000ft vertical loopfield would run about $35K, so yes, higher upfront installment costs.
Yes, the upfront is higher, but given the increased BTU usage in Calgary climate, the potential savings are also higher.
Report is attached, you can see for yourself. Do the systems need to be designed differently? Absolutely! But there is really no reason in terms of capacity and efficiency why they should not work as well in Calgary climate with 42/43 F ground temp and -30F outside design temp than further south. Now the $ in the report are with $0.09/KWH, and I do not know your NG prices, so adjust accordingly.
Your statements about about the lack of effectiveness and that colder climate is not suitable for GSHPs are absolutely wrong. It is a simply an issue of applying the science and technology in the correct way. The rest is just economics, e.g natural gas versus oil versus propane, tax credits etc... |
 Attachment: Calgary.PDF
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docjenser
Veteran Member
Posts:1400
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| 03 Feb 2012 07:55 PM |
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Posted By FBBP on 02 Feb 2012 02:43 PM
Joe - I agree completely that the source is passive solar. I don't understand how January sunshine hitting two feet of snow on a minus 25ºf day will effect the 18 to 36" of frozen soil laying over top the 6' deep slinky.
sesmith - very interesting read! No conclusions though other than in southern Alaska (maritime climate) gshp can compete with high priced fuel oil IF the hydro electric costs remain low. All conclusions indicate that the jury is still out with regard to long term heat loss of source.
doc - heat dominated climates are somewhat subjective ;-) I was born and raise in southern Ontario and have spent 30 plus years in Alberta. I no long consider Ontario to be heat dominated. Maybe balanced?? Five or six years ago a number of gshps went in in this region. One of which I saw the calc's for. My comments to the mech. eng. were "if you look at the proposed cost of the electricity to run the pumps, compressors and backup, it would be cheaper to heat with resistance and then you would not need to install the five miles of 3 phase power line." Yes it was a big custom home. Just because you can afford to doesn't mean you should.Three other systems failed completely within five years. Not saying they were designed properly 'cause I don't know that. But they were at best break even operating cost compared to n.g. At that time gas was running at 6.50 to 7.50 on the open market. Electricity was around five cent give or take a penny. This year power went up to .14 cents and gas is what, just under three bucks? I totally agree with you and Joe and others when you keep repeating that each site needs to do its own due diligence but the amount of times I have had people quote comments like above and talk about how much they are going to save in the Calgary switching to geo just makes me sick. I don't know of a single install over five years old that the owners are still happy with. Odds are that there will be some in the area that are and if anyone in the Calgary area is reading this I would be most interested to hear about your install.
I was curious and ran the numbers with a horizontal slinky, same scenario, and it is the same increase in size, 2.5 times the 3 ton loopfield in WNY.
So the upfront price in WNY for 3 ton would be $22K versus a 5 ton for $32K in Calgary. Report is again attached.
In a 2008 study they did a borehole near Stockholm and measured the temp at 70m depth with 6.8C (44.24F).
http://www.hysave.com/wp-content/uploads/2010/05/Thermosiphon-Loops-for-heat-extraction-from-the-ground-Stockholm-Sweden.pdf |
Attachment: Calgary_slinky.PDF
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FBBP
Veteran Member
Posts:1215
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| 03 Feb 2012 08:15 PM |
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Posted By docjenser on 03 Feb 2012 07:55 PM
I was curious and ran the numbers with a horizontal slinky, same scenario, and it is the same increase in size, 2.5 times the 3 ton loopfield in WNY.
So the upfront price in WNY for 3 ton would be $22K versus a 5 ton for $32K in Calgary. Report is again attached.
In a 2008 study they did a borehole near Stockholm and measured the temp at 70m depth with 6.8C (44.24F).
http://www.hysave.com/wp-content/uploads/2010/05/Thermosiphon-Loops-for-heat-extraction-from-the-ground-Stockholm-Sweden.pdf
Doc - really appreciate you taking the time to do this! Two things. WNY stands for what? Where does the 59000 btuh heat load come from??
As to Sweden, the McQuay manual I referenced was from 2002. Hard to believe that all those heat pumps could have dropped the gwt that much over six years ;-)
Bob |
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FBBP
Veteran Member
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| 03 Feb 2012 08:17 PM |
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Doc - sorry I didn't see your previous post. I'll get back. |
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robinnc
Advanced Member
Posts:586
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| 03 Feb 2012 10:17 PM |
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WNY = Western New York
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FBBP
Veteran Member
Posts:1215
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| 04 Feb 2012 11:14 AM |
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Doc - if you would, what was the heating cost for new york home? At the same .09 cents.
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joe.ami
Veteran Member
Posts:4377
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| 04 Feb 2012 11:24 AM |
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"Joe - The Alaskan study and all the Canadian studies must have had at least one old wife on board than eh? ;-)"
LOL
There are challanges to artic climates, sure, and some cases where geo doesn't make sense. If natural gas is available and a larger system is required, geo would seldom be selected without government subsidy.
You mentioned electric baseboards however and if designed correctly, geo will cost a third to operate.
There is also a difference between heating dominated climates and arctic climates......Do you use the heat more than the airconditioner? Is your heat load higher than the cooling load? You are probably heating dominate.
What if I used the term "hogwash" instead of wives tale? Do you think there were hogs (with good hygiene) in those studies you mention? ;p
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Joe Hardin
www.amicontracting.com
We Dig Comfort!
www.doityourselfgeothermal.com
Dig Your Own Comfort! |
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Palace Geothermal
Veteran Member
Posts:1609
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| 04 Feb 2012 02:51 PM |
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Posted By joe.ami on 04 Feb 2012 11:24 AM
What if I used the term "hogwash" instead of wives tale? Do you think there were hogs (with good hygiene) in those studies you mention? ;p
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Dewayne Dean
<br>www.PalaceGeothermal.com<br>Why settle for 90% when you can have 400%<br>We heat and cool with dirt!<br>visit- http://welserver.com/WEL0114/- to see my system |
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FBBP
Veteran Member
Posts:1215
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| 04 Feb 2012 04:42 PM |
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Posted By joe.ami on 04 Feb 2012 11:24 AM
"Joe - The Alaskan study and all the Canadian studies must have had at least one old wife on board than eh? ;-)"
LOL
There are challanges to artic climates, sure, and some cases where geo doesn't make sense. If natural gas is available and a larger system is required, geo would seldom be selected without government subsidy.
You mentioned electric baseboards however and if designed correctly, geo will cost a third to operate.
There is also a difference between heating dominated climates and arctic climates......Do you use the heat more than the airconditioner? Is your heat load higher than the cooling load? You are probably heating dominate.
What if I used the term "hogwash" instead of wives tale? Do you think there were hogs (with good hygiene) in those studies you mention? ;p
Joe - my point with using resistance heat for that particular situation was simply that he was so sure geo has the green thing to do that he wasn't looking at the whole picture. A huge monster house, all the amenities, even a huge area of snow melt for the patios and driveway. I forget exactly how far he had to bring 3 phase power but I know it was over five miles. And this was in the foothills, higher Hdds and higher heat loss. In spite of comments to the contrary I still think that when you double or quadruple the heat requirement the install cost of ground source doubles or quadruple where as gas installs see only incremental cost inceases for going to a bigger boiler or furnace. Yes if the ground source works the operating costs stay down but the roi is still much longer.
And now that you mention it, yes there was some bureaucrats involved in those studies ;-) |
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docjenser
Veteran Member
Posts:1400
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| 04 Feb 2012 04:53 PM |
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Posted By FBBP on 04 Feb 2012 11:14 AM
Doc - if you would, what was the heating cost for new york home? At the same .09 cents.
No, we are paying 13 cents a KWH. Multiply it by 13/9. |
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docjenser
Veteran Member
Posts:1400
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| 04 Feb 2012 05:00 PM |
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Posted By FBBP on 04 Feb 2012 04:42 PM
Posted By joe.ami on 04 Feb 2012 11:24 AM
"Joe - The Alaskan study and all the Canadian studies must have had at least one old wife on board than eh? ;-)"
LOL
There are challanges to artic climates, sure, and some cases where geo doesn't make sense. If natural gas is available and a larger system is required, geo would seldom be selected without government subsidy.
You mentioned electric baseboards however and if designed correctly, geo will cost a third to operate.
There is also a difference between heating dominated climates and arctic climates......Do you use the heat more than the airconditioner? Is your heat load higher than the cooling load? You are probably heating dominate.
What if I used the term "hogwash" instead of wives tale? Do you think there were hogs (with good hygiene) in those studies you mention? ;p
Joe - my point with using resistance heat for that particular situation was simply that he was so sure geo has the green thing to do that he wasn't looking at the whole picture. A huge monster house, all the amenities, even a huge area of snow melt for the patios and driveway. I forget exactly how far he had to bring 3 phase power but I know it was over five miles. And this was in the foothills, higher Hdds and higher heat loss. In spite of comments to the contrary I still think that when you double or quadruple the heat requirement the install cost of ground source doubles or quadruple where as gas installs see only incremental cost inceases for going to a bigger boiler or furnace. Yes if the ground source works the operating costs stay down but the roi is still much longer.
And now that you mention it, yes there was some bureaucrats involved in those studies ;-)
Again, I would argue the opposite.
If the house has been that far out, there is little likelihood that he is on natural gas. If the load of the house is larger, so is the energy us. If you have an energy hog, one more reason to go geo.
The big cost is not the upfront, but the operating costs over the system's lifetime.
3 phase power for a residential system?
I agree that snowmelt does not much sense with geo. |
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FBBP
Veteran Member
Posts:1215
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| 04 Feb 2012 05:12 PM |
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Posted By docjenser on 04 Feb 2012 04:53 PM
Posted By FBBP on 04 Feb 2012 11:14 AM
Doc - if you would, what was the heating cost for new york home? At the same .09 cents.
No, we are paying 13 cents a KWH. Multiply it by 13/9.
Doc I was hoping you would share the heating cost of the house you modelled for WNY to compare with the one you Modelled for calgary. Leaving the price of power the same makes it easier to compare.
I'm hoping some of my subtrades get back to me on Monday so I can work with some accurate info. |
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docjenser
Veteran Member
Posts:1400
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| 05 Feb 2012 03:00 AM |
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Posted By FBBP on 04 Feb 2012 05:12 PM
Posted By docjenser on 04 Feb 2012 04:53 PM
Posted By FBBP on 04 Feb 2012 11:14 AM
Doc - if you would, what was the heating cost for new york home? At the same .09 cents.
No, we are paying 13 cents a KWH. Multiply it by 13/9.
Doc I was hoping you would share the heating cost of the house you modelled for WNY to compare with the one you Modelled for calgary. Leaving the price of power the same makes it easier to compare.
I'm hoping some of my subtrades get back to me on Monday so I can work with some accurate info.
Here it is. |
Attachment: Calgary_WNY09.PDF
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joe.ami
Veteran Member
Posts:4377
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| 06 Feb 2012 09:33 AM |
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Actually the first ton of geo is the highest the larger the system the lower the price/ton. If geo can work at all (say you are not in the artic circle), it is likely the better choice than exclusively electric resisitance.
About the only thing that might be less expensive to operate would be a wood boiler with elec aux/emergency.
Understand that design is specific and local knowledge trumps our computer models. For instance my computer may say I can cool a home with horizontal ground loops in the mojave, but it may be cheaper with verticals.
Thank you for offering the "definition" of bureaucrats! |
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Joe Hardin
www.amicontracting.com
We Dig Comfort!
www.doityourselfgeothermal.com
Dig Your Own Comfort! |
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FBBP
Veteran Member
Posts:1215
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| 06 Feb 2012 12:00 PM |
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Joe - with regard to the Mojave, I borrow this from a local installers website.
"However, there is a reason why 99% of our installations are vertical borehole. The ground temperatures in this part of the world are such, that to tap into real consistent temperatures below the frost line (required for efficient operation of the geothermal system), your horizontal trench would have to be around 10-12ft deep. Even at 12ft, you’re still looking to add about 25% extra length to your loop field. As an example, a 200ft deep vertical borehole is equivalent to a 250ft long trench at 12ft depth. Unless you have access to very cheap excavation, the cost difference between a vertical and horizontal system becomes negligible when you have to move that much dirt.
In milder climates (parts of BC, and in the States), horizontal systems are a lot more common as ground temperatures & climate allow for more shallow trenches. From our experience in the industry, a lot of the ‘nightmare’ stories around geothermal involve horizontal systems that were not buried deep enough or simply undersized."
The last sentence I think does explain some of the issues in the Calgary area. As you said "local knowledge"
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FBBP
Veteran Member
Posts:1215
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| 06 Feb 2012 02:15 PM |
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Again, I would argue the opposite.
If the house has been that far out, there is little likelihood that he is on natural gas. If the load of the house is larger, so is the energy us. If you have an energy hog, one more reason to go geo.
The big cost is not the upfront, but the operating costs over the system's lifetime.
3 phase power for a residential system?
I agree that snowmelt does not much sense with geo.
Doc most of Alberta has n. gas readily available thanks to government intervention some years ago.
3 phase was strictly for the efficiency of the compressors!!!
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joe.ami
Veteran Member
Posts:4377
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| 07 Feb 2012 12:14 AM |
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loopfields are all about economics. I can tell you we use twice the horizontal loops at 6' deep that we need for verticals. But the verts are twice the price. On the other hand Eric seems to charge less than my horizontal loop guy.......
location, location |
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Joe Hardin
www.amicontracting.com
We Dig Comfort!
www.doityourselfgeothermal.com
Dig Your Own Comfort! |
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