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toby
Troy Mcclure
join:2001-11-13
Seattle, WA

toby to Jack_in_VA

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to Jack_in_VA

Re: Heat pumps - geothermal vs air source

said by Jack_in_VA:

said by telco_mtl:

here in quebec, our utility gives a preferential rate if you have a dual fuel system, usually heat pump until -12c and oil/gas below that. at -15c you get nudged to the higher electricity rate. Air source is generally teh way we go due to the time it takes to recoup investment because of our inexpensive electricity.

What are your rates? It appears that Canada has reasonable rates. Evidently you don't have the environmental crazies that oppose any upgrading or new electrical sources. Even our Hydro the environmental wacko's are forcing the breech of some of our hydro producing dams so the "Fish" can swim upstream.

My utility is trying to build a new power plant not too far from me and the crazies have come out of their caves and so far have it stopped.

Oh, those whackos.

Blocking the rivers of course harms the environment.

The geothermal mentioned in this thread is actually solar, where the sun warms the ground, not the heat from the earth like is used in place like Iceland.

Nuclear is the best power, as long as it isnn't owned by private irresponsible companies of course.

whizkid3
MVM
join:2002-02-21
Queens, NY

whizkid3

MVM

said by toby:

The geothermal mentioned in this thread is actually solar, where the sun warms the ground, not the heat from the earth like is used in place like Iceland.

Ground-source heat pump is the same thing as geothermal heat-exchange. Geothermal comes in basically three flavors: horizontal surface coils, shallow-well and deep-well. It sounds as if the OP is talking about surface geothermal. This requires a relatively large amount of land to bury the coils; horizontally buried at typically about ten feet deep. Shallow-well uses drilled wells as opposed to simply placing coils horizontally in the ground. Shallow well requires less land than horizontal but still takes a lot of land depending on its application. And its not as shallow as you think; the wells can be from 50' to hundreds of feet deep; most typically about 80' to 100' feet deep. Deep well is used where there is not enough land to have many, many wells.

Its not just Iceland where geo-thermal energy is being used. Geothermal energy has been around since the 1800's in the USA. Deep-well geothermal is being used right in Manhattan to provide HVAC to buildings. There are geothermal installations all across the United States. The US leads the world in geothermal electricity production. It doesn't require 'volcanic activity'!
ground-source heat pump which is different from Geothermal heating & cooling. Bear in mind, all of these systems use 'heat pumps' to work. Just not small residential units.

fifty nine
join:2002-09-25
Sussex, NJ

1 recommendation

fifty nine

Member

said by whizkid3:

Geothermal comes in basically three flavors: horizontal surface coils, shallow-well and deep-well. It sounds as if the OP is talking about surface geothermal. This requires a relatively large amount of land to bury the coils; horizontally buried at typically about ten feet deep. Shallow-well uses drilled wells as opposed to simply placing coils horizontally in the ground. Shallow well requires less land than horizontal but still takes a lot of land depending on its application. And its not as shallow as you think; the wells can be from 50' to hundreds of feet deep; most typically about 80' to 100' feet deep. Deep well is used where there is not enough land to have many, many wells.

There are a few types, actually.

We are looking into what you call "surface geothermal" (horizontal loop) as well as where the loops are put down a drilled well (vertical loop). Both are closed loops with glycol refrigerant. Some even put the loops at the bottom of a body of water like a pond or lake.

There's also open loop where you just use the ground water and discharge it somewhere.

We are looking at either a horizontal loop or vertical loop. We have the land for both but the horizontal loop involves significant tree cutting.

tstolze
Premium Member
join:2003-08-08
O Fallon, MO

tstolze

Premium Member

said by fifty nine:

We are looking at either a horizontal loop or vertical loop. We have the land for both but the horizontal loop involves significant tree cutting.

Some installers are now using directional boring for horizontal loops. Horizontal is defiantly cheaper and with a boring rig the trees would be a non issue.

cdru
Go Colts
MVM
join:2003-05-14
Fort Wayne, IN

cdru to whizkid3

MVM

to whizkid3
said by whizkid3:

Shallow-well uses drilled wells as opposed to simply placing coils horizontally in the ground. Shallow well requires less land than horizontal but still takes a lot of land depending on its application.

For most residential applications, a 10'x10' area is the minimum that's required. More space the better, but if there's a clear area that size, vertical loops probably can be installed.

And its not as shallow as you think; the wells can be from 50' to hundreds of feet deep; most typically about 80' to 100' feet deep. Deep well is used where there is not enough land to have many, many wells.

Up to 150' is as deep as we recommend but no deeper than 400' for a single vertical loop.

fifty nine
join:2002-09-25
Sussex, NJ

fifty nine to tstolze

Member

to tstolze
said by tstolze:

said by fifty nine:

We are looking at either a horizontal loop or vertical loop. We have the land for both but the horizontal loop involves significant tree cutting.

Some installers are now using directional boring for horizontal loops. Horizontal is defiantly cheaper and with a boring rig the trees would be a non issue.

I don't even mind cutting the trees (we'll use the firewood), but if it comes out to more than drilling a vertical loop, it won't be worth it.

The directional boring sounds interesting. My cousin does something similar for a living but he works in the oil and gas industry. He is a directional driller. Quite a difference but probably similar concepts.

We have 6.15 acres here so we have options. It's too bad we don't have a pond or lake on the property because that would have been ideal. I know someone nearby who lives on a lakefront and put the loop in the lake.

Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA

Premium Member

said by fifty nine:

said by tstolze:

said by fifty nine:

We are looking at either a horizontal loop or vertical loop. We have the land for both but the horizontal loop involves significant tree cutting.

Some installers are now using directional boring for horizontal loops. Horizontal is defiantly cheaper and with a boring rig the trees would be a non issue.

I don't even mind cutting the trees (we'll use the firewood), but if it comes out to more than drilling a vertical loop, it won't be worth it.

The directional boring sounds interesting. My cousin does something similar for a living but he works in the oil and gas industry. He is a directional driller. Quite a difference but probably similar concepts.

We have 6.15 acres here so we have options. It's too bad we don't have a pond or lake on the property because that would have been ideal. I know someone nearby who lives on a lakefront and put the loop in the lake.

How cold does the lake water get in winter? Would that not negate some from the natural warmth of the well method? We looked at putting it in the water but we're on the coast and the marine life would coat it in about a year.

An open system utilizing my well and dumping the water was a better option but wasteful.

fifty nine
join:2002-09-25
Sussex, NJ

fifty nine

Member

said by Jack_in_VA:

How cold does the lake water get in winter? Would that not negate some from the natural warmth of the well method? We looked at putting it in the water but we're on the coast and the marine life would coat it in about a year.

An open system utilizing my well and dumping the water was a better option but wasteful.

The water temperature stays relatively constant below a certain depth is what I was told.

The entire lake doesn't freeze, just 2-4 feet of the surface.

cdru
Go Colts
MVM
join:2003-05-14
Fort Wayne, IN

cdru to Jack_in_VA

MVM

to Jack_in_VA
said by Jack_in_VA:

How cold does the lake water get in winter? Would that not negate some from the natural warmth of the well method? We looked at putting it in the water but we're on the coast and the marine life would coat it in about a year.

Our 115k sq ft manufacturing plant (~85k sq ft factory, the rest office) is conditioned using multiple units on multiple slinky pond loops totaling 153 tons. A lake won't freeze over any more then what the ground will freeze. Anything more than a couple of feet and the lake will be liquid still.

An open system utilizing my well and dumping the water was a better option but wasteful.

A summer camp that I grew up at used an open loop for their main building. Sitting right next to a major lake, the well was very shallow, basically unlimited, and could easily be dumped right back into the lake. The energy required to pump the water from the well wasn't all that much more than what was required to run a closed loop.