# Geo thermal heat pumps



## karl (Jun 15, 2008)

I read online where 1997 statistics  say the average home consumption of heating oil is 730 gallons a year.  Now that it's 5 bucks a gallon.  That's $3650 dollars a year.  I also read where the average installed cost of a geo thermal heat pump is $7500.  It sounds like a no brainer to me.  Even if it only cuts the cost of heating in half, that's a four year pay back.  Throw in cheaper cooling in the summer and it should be less than 4 years.

I wonder if these things are finally going to take off?


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## begreen (Jun 15, 2008)

I looked into this for our house. The cost was closer to $20K for the full installation. A big chunk is the in-ground loops. We ended up getting a very high efficiency air to air heat pump instead for less than half the priced and are very happy with it.


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## Jerry_NJ (Jun 15, 2008)

Do a search on Geothermal and you'll find some data, including inputs from me.

The cost of a geothermal heat pump depends on the size and difficulty of installing the geothermal loop.  In any case I'd say expect to pay a lot more than $7,500 even for a small unit.  

I paid about $12,000 15 years ago for a multispeed Water Furnace (Still on the market, and mine has been trouble free and efficient).  My house is just over 2000 square feet and a two story with an all electric insulation construction.  The unit was designed to hold the house at 70 degrees with the outside temperature at 0 degrees, of course that means the heat pump would be running 24 hours a day in high speed.  It also has two stages of resistive heat for emergency and supplemental heating.  The resistive heat has never been on other than when I bring the demand temperature up too fast.

At the current electric rates in NJ and the efficiency of my heat pump, it cost me less to heat with electricity than with wood if I have to buy wood at the going split and delivered costs.


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## karl (Jun 15, 2008)

$12,000 ???

I got this from the California Energy Commission.  I bet there is competition in CA that makes it cheaper.


As a rule of thumb, a geothermal heat pump system costs about $2,500 per ton of capacity. The typically sized home would use a three-ton unit costing roughly $7,500. That initial cost is nearly twice the price of a regular heat pump system that would probably cost about $4,000, with air conditioning.


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## BrotherBart (Jun 15, 2008)

The estimates to replace my busted air to air heatpump w/airconditioning all ran around eight grand with existing ductwork and no holes to punch in the yard like a geo would require.


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## begreen (Jun 16, 2008)

Yes, I suspect the $7500 for a 3 ton unit is just for the heat pump and not for the outdoor setup which can cost more than the actual heat pump. Then there is the tying in to the existing system. My new heatpump system was about $9K and I did most of the ductwork.


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## Jerry_NJ (Jun 16, 2008)

That could explain the unexpected low cost estimate, just the heat pump.  I paid about $8K for the Heat Pump and installation in ducts designed to handle a HP and about $4K for the ground loop, two 250' vertical loops, put in by a well drilling outfit.   My property is too rocky to "plow" a horizontal loop, which is less expensive is you have sandy soil, few to no rocks.


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## flyingcow (Jun 16, 2008)

I've always been intrigued this type of set up. But I'm assuming that it would not work well in northern areas that have deep frost levels?  Probably I'm missing something.


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## Jerry_NJ (Jun 16, 2008)

Deep frost levels  outside the arctic are a few feet down.  That's the key behind geothermal, the outside air temperature makes no difference. Heating at below zero or cooling at over 100 degrees, the geothermal is working against "deep" earth temperatures.  Here in NJ that is around 50 degrees year round. 

My system is  a closed loop, thus the BTU transfer hast to take place through the walls of the ground loop.  An open loop system would pump water from the water table, run it through the heat pump and pump it back into the water table.  This mode is not allowed in NJ, but has some clear advantages from the efficiency point of view.


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## karl (Jun 16, 2008)

I've priced  4 ton geothermal units at about $3500.  I figured the work in the yard would be the big expense.  My father-in-law used to own a core drilling business too bad I didn't have him drill the holes while he still had the equipment.

My research shows  one hole per ton is what they are using.  They go 150-170 feet deep.   The other way is to dig a hole and bury a slinky type array of pipes in the ground. They dig it about 6 feet deep and im guessing 5 or 6 feet wide and 75 feet a ton long.  Thats alot of yard to tear up. I'd rather drill the holes.

I think I'll look into having a well dug.  I've been wanting one for irigation purposes for awhile.  If the flow is enough.  I'll have them dig a return well and do the open loop system.


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## Redox (Jun 16, 2008)

karl said:
			
		

> I've priced  4 ton geothermal units at about $3500.  I figured the work in the yard would be the big expense.  My father-in-law used to own a core drilling business too bad I didn't have him drill the holes while he still had the equipment.
> 
> My research shows  one hole per ton is what they are using.  They go 150-170 feet deep.   The other way is to dig a hole and bury a slinky type array of pipes in the ground. They dig it about 6 feet deep and im guessing 5 or 6 feet wide and 75 feet a ton long.  Thats alot of yard to tear up. I'd rather drill the holes.
> 
> I think I'll look into having a well dug.  I've been wanting one for irigation purposes for awhile.  If the flow is enough.  I'll have them dig a return well and do the open loop system.



You'll need the well, but will have to put the loop in it.  Most jurisdictions don't want you to reinject anything back into the ground.  There's too much of a chance to contaminate your aquifer.  Sorry!

Parental units were quoted $30K a few years back for 2 GSHP systems in new construction totaling 6 tons.  This was including ductwork by a "Gucci" contractor and all the bells and whistles EXCEPT wells.  They ended up with an air to air heat pump instead.

I think the price will drop as more contractors get some experience under their belts and more manufacturers come on line.  The biz is still in its infancy, IMHO.

I refuse to call it "geothermal".  Besides GSHP is easier to spell...

Chris


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## mikeathens (Jun 16, 2008)

BeGreen said:
			
		

> Yes, I suspect the $7500 for a 3 ton unit is just for the heat pump and not for the outdoor setup which can cost more than the actual heat pump. Then there is the tying in to the existing system. My new heatpump system was about $9K and I did most of the ductwork.



Geothermal was insanely priced for my place.  I can't even remember.  We ended up with an air-source, completely installed, with dehumidifier.  It was $6,000 installed in 2006...and they did all of the retrofitting for our old house that didn't have ANY ductwork.  Man, BG, if mine was $9K and I had to do the ducts, I think I'd still be without anyhting but wood heat, and nothing for these sticky Ohio summers!  Some of our "crawl spaces" are about 6" high.  I still can't figure out how they gots the duscts through that...

I think if I had to rely on a heatpump for year-round heating and cooling, though, I would have looked a lot more closely at geothermal.  The only time these past two years that we NEEDED the heatpump were the few days in January when child #2 was born and we were at the hospital.  We would have lost some plumbing fixtures for sure without it.  If I remember correctly, it was hovering around 17 F for 3 days straight.


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## Jerry_NJ (Jun 16, 2008)

Geothermal does pay if you use central heating /air-conditioning.  I did not use any wood or other supplemental heating over the last twelve months and I'll estimate my 12 months electric total at about $2,400, or $200 a month.  We have about the same summer weather as much of Ohio, and the A/C is on now and has been on most day-time hours for the last 7-10 days.   We have no other energy sources, electric cooking, hot water, washer and dryer (and my wife uses the cloths dryer some, I do not, I use the cloths line).  Of course lights and tv, most lights are high efficiency units.  I believe the average American household uses about 1000 KWH per month, my average is only 30% above that for an ALL electric house.

As noted in my signature and other posts, I have installed a new Quadrafire Insert in my first floor fireplace and I do plan of burning some wood for heat this coming winter, as much as possible with "free" wood I gather.  If I have to pay $300 a cord for hardwood, my heat pump may be cheaper to heat with...conditioned on a continuing gradual increase in the cost of electricity (almost totally coal and nuclear here in NJ).  This insert and the coal/wood air tight in the basement are otherwise for emergency or enjoyment of a toasty warm room on occasions.

Editorial addition:  The new Quadrafire installed is over $4,000. This approaches the cost Mike paid in 2006 for a new air-to-air heat pump, installed.  So, when justifying investment, wood has some work to do before I can payback to cost of the new insert.


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## begreen (Jun 16, 2008)

That's similar to our house. For comparison, with the air to air heat pump our average electric use for all electric house (except propane cooktop) is about 1400kw in winter, but less than 800 in the summer. (That's because we've only used the AC once.) Spring and fall run between 800-1000kw/month depending on the weather. 

However, the big advantage with a properly designed geothermal system is that it will heat in cold winter temps. Air to air efficiency diminishes below freezing. Fortunately we don't often get below freezing here. When it does we are using the woodstove for our backup heat instead of the electric coils.


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## Jerry_NJ (Jun 16, 2008)

BeGreen, thanks for the reference numbers.  Yes, in the mild climate (I lived in Seattle 1958-66) there is no need to go geothermal, a high efficiency air-to-air should be close to as energy effective, and with your wood supplemental heating you've got a near optimum cost environment.


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## mikeathens (Jun 17, 2008)

My dad has a Water Furnace at his cabin in the woods.  I was there yesterday to meet the contractor who had to replace the compressor (it was only 2 years old).  I believe he paid something like $10,000 for new construction.  Anyhow, it was under warranty, so nothing more than an inconvenience..

As the contractor finished up and the goethermal system was humming along, I walked outside and realized how silent it was.  I know that my air-source heat pump really makes a lot of noise (when you're used to listening to the wood thrushes and towhees).

This, in my opinion, is one of the huge benefits of geothermal.  No outdoor noise, no unsightly outdoor unit.  Complete silence.


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## Jerry_NJ (Jun 17, 2008)

Yes, the absence of any outdoor unit is a plus, and that means all your equipment, save the ground loop, is inside and protected from weather.  Im still running my Waterfurnace without any problems/failures, now over 15 years.  Keeping my fingers crossed. 

I have people come into the house in the summer an be amazed how cool it is in the house...i.e., they don't see an external unit and come in programed that I don't have A/C...I say we have a geothermal (or ground source) heat pump.  We're on a large property, several acres, so the noise of an outside unit would not disturber neighbors,  but the quiet, no sound/noise, would be very welcome to near by neighbors in a development type area.


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## tkirk22 (Jun 18, 2008)

Question for you guys:

I'm in the VA mountains with an old AC unit that should be replaced at some point. We have a wood insert for heat and electric baseboard for backup. I'm thinking about replacing the AC unit with a ground source heat pump at some point. I have a backhoe so the ground loop installation cost is minimal.

What do you guys think? Is it a good move?


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## Jerry_NJ (Jun 18, 2008)

As said, I installed one, paying the full cost of installation, and the unit has paid dividends $$$ every year, and now saves me thousands every year over the cost of the equivalent oil heat.  Of course, if you don't use it, i.e., heat with wood, it will not pay for itself.  Note, it should be much more efficient at A/C too, an ERR of 20+ at 100+ degrees air temperature (independent of air temperature) whereas an air-to-air will not give more than 12-15 at high air temperatures.


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## Redox (Jun 19, 2008)

Kirk22 said:
			
		

> Question for you guys:
> 
> I'm in the VA mountains with an old AC unit that should be replaced at some point. We have a wood insert for heat and electric baseboard for backup. I'm thinking about replacing the AC unit with a ground source heat pump at some point. I have a backhoe so the ground loop installation cost is minimal.
> 
> What do you guys think? Is it a good move?



If you plan on staying put for a while, a GSHP is the best long term investment that you could make in HVAC, other than a wood stove, of course.  That being said, how's the rest of the house?  If your insulation isn't up to snuff and you ductwork is poor, you are never going to be happy and may just wind up damaging the equipment.  The geology is also going to play a factor also.  If your yard is full of rocks (like mine), you are going to have a heck of a time burying all that tubing.  Also ask yourself the question: Is it worth spending close to $10K on something you are going to only use a few times a year?  If you are really using the wood insert a lot, the savings will be minimal and may not be justified.  A conventional air-air heat pump makes very good sense in this case.  They also need good ductwork and insulation, but are less than half the cost.  Even electric baseboard is a good deal if you only use it a few times a year.

Chris


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## cbrodsky (Jun 23, 2008)

This thread has got me thinking - prior to wood, we were using 800-1000 gallons a year.  Now we're down to 200 with solar HW and wood.  I'd love to eliminate the rest.

Has anyone done a GSHP exchanging with their domestic water well?  I know our well was drilled 800 feet deep and then hyrdrofractured - after which there is a huge amount of water available.

While this one loop wouldn't do the entire house on its own, I'm wondering if it would be a good cost effective solution to eliminate the end of our oil use, as well as providing A/C?  In the summer we use at most two 5000 BTU window units during the worst periods - lots of big trees for shade.

-Colin


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## Redox (Jun 23, 2008)

A friend of mine is conditioning his whole house summer and winter with a GSHP using his well water reinjecting it into the same well.  I'm not sure it's code, but it works!  His only complaint is that his drinking water is 80+ degrees in the summer.  It seems to me you will pay more to heat your HW, but this could be offset by a desuperheater coil on the heat pump.  Hot water in the summer is almost a freebie!

I am going to wonder out loud how much pump horsepower you need to bring water up from 800 feet and how this compares to those two little air conditioners.  It may not be worth it in the long run...

Chris


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## cbrodsky (Jun 23, 2008)

Redox said:
			
		

> A friend of mine is conditioning his whole house summer and winter with a GSHP using his well water reinjecting it into the same well.  I'm not sure it's code, but it works!  His only complaint is that his drinking water is 80+ degrees in the summer.  It seems to me you will pay more to heat your HW, but this could be offset by a desuperheater coil on the heat pump.  Hot water in the summer is almost a freebie!
> 
> I am going to wonder out loud how much pump horsepower you need to bring water up from 800 feet and how this compares to those two little air conditioners.  It may not be worth it in the long run...
> 
> Chris



I seem to think that once drilled through and hydrofractured, the water table actually ended up being a lot higher.  But I doubt that discharging an open loop to the well is code anyway - I was wondering if once can simply insert a closed tubing loop into the well for heat transfer, in which case the pump load would be much lower as well.

From what I've read, you can get something in the 12-15,000 BTU range out of a typical vertical well used for these systems.  I'm also guessing they are not typically as deep or large as a drinking well, in which case maybe you could get closer to 20,000 BTU.  I think that would be enough to easily stay warm with the 3-4 cords of wood I burn off the stove, and would be enough heat to keep the house from freezing when on vacation, enabling me to quit using oil.  I'd also convert our first floor to radiant to make the job easier - only place I'd need baseboard is supplemental heat for upstairs BRs, and that could be run at 140 F and still do the job.

-Colin


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## Highbeam (Jun 23, 2008)

If using a closed loop then you aren't really lifting water 800', the circulation pump only sees the losses due to friction through that long loop. Your domestic pump is probably pretty stout. Also remember that even though the well might be 800 feet deep, the domestic pump might only be 300-400' down. Sometimes the water fills up the well once you get to it. 

If your pump is not at the bottome then you are asking for trouble trying to sneak a circulation loop down beside it. It would sure stink to get it all jambed up in there.


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## cbrodsky (Jun 23, 2008)

Highbeam said:
			
		

> If using a closed loop then you aren't really lifting water 800', the circulation pump only sees the losses due to friction through that long loop. Your domestic pump is probably pretty stout. Also remember that even though the well might be 800 feet deep, the domestic pump might only be 300-400' down. Sometimes the water fills up the well once you get to it.
> 
> If your pump is not at the bottome then you are asking for trouble trying to sneak a circulation loop down beside it. It would sure stink to get it all jambed up in there.



That's kind of what I was getting at - closed loop would have very low power requirement.

Not sure how easy it is to tuck something else down the same well.  Copper would give you some rigidity to help keep it out of the way on the side, and would be awesome for heat transfer, but that could get pricey quickly.  And not sure how much clearance there would be to take a well pump up and down.

-Colin


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## Redox (Jun 23, 2008)

Since the typical well is 4" diameter and the pump is just a shade smaller than that, it would be impossible to get a loop down past the pump.  I also think you could wind up with a mess if you dropped a loop in without some kind of support system.  This is uncharted territory AFAIK and may have other problems such as cross contamination should the heat pump loop develop a leak.  I'm not sure I would want to be the guinea pig...

I can definitely understand the desire to completely cut yourself off from the oil barons, but installing a full zoot heat pump for only occasional use doesn't seem like it would pay back very fast, IMHO.  The system you have is already paid for and probably works well enough for the few times you would need it.  If it is having problems, then you might want to explore less expensive options, as you aren't going to be using it all that much.

Just my$.02

Chris


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## Jerry_NJ (Jun 24, 2008)

Only closed loop systems are legal in NJ.  This was true even 15+ years ago when mine was installed.  I also have a well for water, best I recall a the moment it is about 125' deep, so my closed loop heat exchangers (two loops) at 250 feet spend a lot of time in water (not dirt) and that should go a long way to keep the loop temperature on the return side near geothermal (ground) temperature/well-water the desired result.  I can say my circulation pumps don't use a lot of power, mine is two stage at the circulation level too, but they look heavy duty, are sizeable.  The two stage circulation pump is part of the maximize economy strategy, when the compressor is running on low speed, the HP is using the lower power setting for pumping the closed loop too.


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## Redox (Jun 24, 2008)

I thought the wells were supposed to be packed with mud or bentonite or something...

Chris


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## Wet1 (Jun 26, 2008)

I was just reading over this thread with casual educational interest and it reminded me about the two unused wells I have on my property (both within 60' of my house).   I live very close to the ocean so the ground below the topsoil is mostly sand and the water table is high, probably within 5'-8'.  It might even be higher than this as all my neighbors have sump pumps running from spring through fall.  We now have city water so the wells aren't used, but they always have water in them.   They both have cement slabs covering them and each is several feet in internal diameter and of unknown depth.  

Would/could there be any value of using these for heating or cooling?  Ideas???


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## mbcijim (Jun 27, 2008)

Geothermal Pricing (GSHP) -

I am building a new house as we speak.  I received two prices (May 2008), at about the same price.  $23,000 + ground loop excavation (self performed).  
This is for 7 tons (2 units 1# 5 ton, 1# 2 ton), hot water, and ductwork (hot air system).  The house is 3,200 sft plus a basment of 2,200 sft.  The entire house is conditioned.  This is eastern rural PA.  I've spoken to two families in the same area as me with about the same size new house and a GSHP  Neither electric bill has ever exceeded $200.  

My HVAC contractor says that all I am saving energy wise over an air exchange Heat Pump is a 1/2 HP pump.  Without a doubt, an air exchange heat pump is a better return on your investment.  The savings to go to ground source probably don't justify ground source.  I have the $, I'm 32, and plan on living in the house for a long time, so I did it.  I am looking at the very long term picture and could justify the additional money.  

If you want cheap heat, go for coal or wood.  They both have less $/BTU cost, but both involve work.  It is cheaper than wood pellets, corn, and just about everything else.  I wanted the cheapest heat with no work.


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## Jerry_NJ (Jun 27, 2008)

I don't understand you HVAC contractors comment about a 1/2 hp pump.  At temperatures below 30 degrees the Geo will save a lot more over an air-to-air than the energy used by a 1/2 hp pump.  Same for A/C when the air temps are in the 90s.  Both of these exist often in eastern PA, and central/western NJ where I live.  I don't understand the not over $200 either, for a 3,200 SqFt home, plus basement.  I have a 2,000 SqFt home plus basement and I saw bills nearing $300 for February.  Electricity in PA may be lower cost than NJ, but I'll bet not 30% less expensive.


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## mbcijim (Jun 27, 2008)

Jerry_NJ said:
			
		

> I don't understand you HVAC contractors comment about a 1/2 hp pump.  At temperatures below 30 degrees the Geo will save a lot more over an air-to-air than the energy used by a 1/2 hp pump.  Same for A/C when the air temps are in the 90s.  Both of these exist often in eastern PA, and central/western NJ where I live.  I don't understand the not over $200 either, for a 3,200 SqFt home, plus basement.  I have a 2,000 SqFt home plus basement and I saw bills nearing $300 for February.  Electricity in PA may be lower cost than NJ, but I'll bet not 30% less expensive.



I think his comment about the 1/2 HP pump meant if you look at the two units side by side that is the difference.  You make a good point about air temps though, you're right about that.  

Hopefully the $200/month people aren't lying to me!  I am just repeating what they said.  Are you saying you have a GSHP and it cost you $300/month?  PA's electric cost is about $.12/KW.


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## Jerry_NJ (Jun 27, 2008)

Right, the difference is the pump, in my system two pumps (two speeds, runs in low as long as it can to increase efficiency) to circulate liquid in the ground loop..and that's another difference, the ground loop.  

I had only one month last winter near $300, maybe it was $279, I was just estimating against the $200 number.  I was paying 15 cents per KWH, so that's part of the reason for a higher cost at my end.  Still, I have onlly 2,000 sqft and that's a two story with an "all electric" construction (circa 1985).  We have R38 in the ceiling and R19 in the walls.


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## Highbeam (Jun 27, 2008)

Perhaps the 200$ was their annual average. I can appreciate the concept of a no-work source of heat but also greatly appreciate the value of an additional alternative source that is independent of electricity even if it includes some work. I wish we had a heat pump of ground or air source.

The installs into vertical wells that I've read about all included a bentonite or other fill of the well around the geo loop to ensure good contact with the earth for thermal transfer. You can depend on the ground to be there but the water level may drop and leave your geoloop in the air. People have also been known to use ponds as a thermal sink and just lay loops of poly geo loop in the pond. Imagine that, in the summer, your home's AC load is actually heating the pond for swimming.


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## Jerry_NJ (Jun 27, 2008)

Yes, there was some fill in my vertical loops, and my contract didn't include cleaning up the stuff pulled out of the holes while drilling.  How much can that be for two holes?  A lot, it took a lot of work to remove the "slag" from my property, actually I just moved it to a hill side on my property.

The really great thing about A/C is the waste heat, if you can capture it for your hot water needs, bingo, free hot water.  My system has a high temperature loop that feeds in/out of my existing water heater through the drain tap, bad news: the dual use of the one 1/2" hole (I'm estimating the size, coule be 3/4") is the water channels are so narrow that they get stopped up easily, and have, I no longer try to use.  So, no FREE hot water for me.  A simple auxiliary tank with a dedicated and separate in/out would fix the problem.  I don't know if the HP or A/C suppliers have such a offer.  Keep in mind, one doesn't need a heat pump for this, as the only time you have throw-away heat is when A/C is running.


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## Redox (Jun 27, 2008)

The difference is a lot more than the pump.  First off, you will not need an outdoor fan motor.  Air source units will probably have anything from 1/10 to 1/4 hp fan on the outdoor unit.  The pump will probably be bigger than that, but the real savings comes from the differing temperatures on the water side.  Since the earth moderates the temperature, there will be a smaller temperature difference and this delta T is the primary governing factor in efficiency in a refrigeration system.  There is also no defrost cycle on a GSHP which kills your efficiency in the winter as the humidity goes up and the temperature goes down.

You will need the same size circuit to start that compressor, but the running amps will be much lower on a GSHP because the compressor isn't working as hard.  You will also need a pretty serious generator if you want to use one in a power failure, if that is a consideration.  The $200-300 bills mentioned here would seem to jibe with what I am hearing for our climate.  If you want the most efficient system available, go ground source.  If you aren't going to be using it 24/7 or don't need a lot of A/C, air source is simpler and significantly cheaper.  As the price goes up, so does efficiency, but spending twice as much on a heat pump will probably not cut your bill in half and will likely cost more if it breaks.

You can heat water with a heat pump with a device called a desuperheater.  It is nothing more than a heat exchanger and a small circulator that cools the hot gas as it leaves the compressor regardless of whether you are heating or cooling.  This option is common on GSHPs but I don't think I've ever seen one factory installed on a regular heat pump or A/C.  They can be added, but it requires breaking into the refrigeration system and will probably void a warranty if it exists.  They are almost "free" in the cooling mode, but are stealing heat in the winter.  They work best when they are installed as a preheat system similar to a solar water heater.  I haven't seen a whole lot of them around as they make more sense in southern climates where you are running the A/C more.  I'm still waiting for someone to come out with a dedicated water heating heat pump.  So far, all I've been able to find is a little fractional horsepower job that cools the basement:

http://www.aers.com/etech_residential_water_heating.html

BTW, anybody know what it costs to drill a well these days?

Chris


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## mbcijim (Jun 28, 2008)

Thank you guys for correcting my comments on just the fan difference.  I'm thinking my HVAC guy is feeding me a line of BS.  Anyway, I'm committed to GSHP at this point.  I did already buy a Summit Classic for the house for backup, and maybe  a hobby!  I love sitting around a wood stove in the winter...


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## Jerry_NJ (Jun 28, 2008)

While talking about geothermal, my experience suggests the efficiency for heating verses cooling isn't symmetrical/equal. Absent any measurement, and I suppose the BTU specification for heating and cooling should tell the story, I may dig out the specs next, it seems to me I get more BTUs per dollar heating over cooling.

Here's what made me think about it, were on A/C now and I'd say the outside temperature is about 90 degrees, inside about 75 degrees.  It seems to me the A/C is running a good bit and I expect an electric bill in the neighborhood of what I get in the winter when I"m heating to 65 degrees and the outside temperature is about 30 degrees.  My point?  It seems to me it cost me as much to take 15 degrees off in the summer as it does to add 35 degrees in the winter. It can't be the insulation, it works both ways...maybe the sun is part of the answer.  In th winter the house gets full southern exposure and this helps warm the house.  In the summer I get some shade to help shield the house, but the house still gets some warming from the sun hitting the house.  In addition, we pay about 15% more for electricity in the summer, I suppose about 18 cents per KWH this summer.


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## Redox (Jun 29, 2008)

Jerry_NJ said:
			
		

> While talking about geothermal, my experience suggests the efficiency for heating verses cooling isn't symmetrical/equal. Absent any measurement, and I suppose the BTU specification for heating and cooling should tell the story, I may dig out the specs next, it seems to me I get more BTUs per dollar heating over cooling.



That difference is due to the heat of the motor/compressor.  In the winter, this heat is a benefit and is roughly equal to electric resistance heat on top of the heat from the refrigeration effect.  In the summer, this is just waste heat and needs to be rejected along with the refrigeration heat. 

Heat pumps also draw more current in the cooling mode than when heating, but the difference is smaller on water source.  You noticed that most utilities charge more per kw in the summer but also consider that most homes are self heating due to internal gains from lights and appliances.  Humans also emit heat and humidity as well and this is more noticeable in the summer.

Chris


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## syd3006 (Jun 29, 2008)

I am in the process of having a "ground source heat pump" installed. The price for everything installed not including electrical or duct-work is $15700.00 and change. This is a 4 ton unit with electric backup and provisions for heating my hot water. The provincial and federal governments will reimburse me $3500 each for a total of $7000.00. I am required to have an inspection of my house which basically tells how energy efficient it is. The inspector seals off a door and then installs a fan type gadget which he gradually restricts the air flow through and this tells him how much air or heat loss I have. For this inspection I paid $315.00 of which the government will reimburse $150.00. Once everything has been installed and is up and running I have to get another inspection which I will have to pay another $300.00 for. If all goes as it is supposed to I will get all my rebate cheques within 90 days.


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## Redox (Jun 29, 2008)

syd3006 said:
			
		

> I am in the process of having a "ground source heat pump" installed. The price for everything installed not including electrical or duct-work is $15700.00 and change. This is a 4 ton unit with electric backup and provisions for heating my hot water. The provincial and federal governments will reimburse me $3500 each for a total of $7000.00. I am required to have an inspection of my house which basically tells how energy efficient it is. The inspector seals off a door and then installs a fan type gadget which he gradually restricts the air flow through and this tells him how much air or heat loss I have. For this inspection I paid $315.00 of which the government will reimburse $150.00. Once everything has been installed and is up and running I have to get another inspection which I will have to pay another $300.00 for. If all goes as it is supposed to I will get all my rebate cheques within 90 days.



That sounds like a good deal to me!  Does this price include wells or loop installation?  How big and how old is the house?  I hate to be a pest, but I like details. 

Thanks,
Chris


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## Jerry_NJ (Jun 29, 2008)

Sounds like a great price (what is the mfg for the heat pump?) to me. I paid about $12K for a 4 ton unit installed as a replacement for an air-to-air.  Of this about $4K was for the ground loops, two 500' vertical loops or 2K feet at an average depth of 250', in the water aquifer most of the distance.  I got a $3K rebate from the power company, with the larger rebate you quote, your price is no more than mine was in 1994, surprising.  

I do recall a lower cost unit back when I was shopping that directly buried the heat exchanger, big coil of copper pipe so there was less digging, less cost.  I didn't like the design, but can say it did qualify for the power company rebate, so their engineers thought it was ok efficiency-wise.


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## syd3006 (Jun 29, 2008)

Yes the price includes the installation of the ground loop, I have it in already, I'm just waiting for the rest of the system to be installed.  As far as the grant goes I don't think the size or age of the house has a bearing as long as you are converting to one of the energy efficient systems they approve.  My house is 1056 square feet and was built in 1978.  The name of the company that makes the "Heat pump" is "Hydron" they are located in Mitchell, South Dakota.


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## Jerry_NJ (Jun 29, 2008)

I found the Hydron web site a bit difficult to read, but found one good reference:  http://www.ari.org for independent specs on HPs, and other compressor gear.  I didn't see Hydron on the ARI site.

The Hydron site listings left me with the conclusion that it is supplied only as an open loop system, is that right?  We can not run open loop, so if I should outlive my existing geothermal I'll not be able to consider Hydron as a replacement.  The COP suggested, 3.5, in one of the Hydron listings isn't quite as high as my two speed Waterfurnace HP, it is rated at 4.3 in low speed with a loop temp of 32 degrees F.  Of course that's a limit and I expect to get better under most conditions as the loop is usually way above 32 degrees, more likely in the 40s.  My loop has antifreeze so it can run below freezing for water.


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## Redox (Jun 30, 2008)

syd3006 said:
			
		

> Yes the price includes the installation of the ground loop, I have it in already, I'm just waiting for the rest of the system to be installed.  As far as the grant goes I don't think the size or age of the house has a bearing as long as you are converting to one of the energy efficient systems they approve.  My house is 1056 square feet and was built in 1978.  The name of the company that makes the "Heat pump" is "Hydron" they are located in Mitchell, South Dakota.



I hate to be throwing questions this late in the game at you, but has anyone done a heat load calculation on your house?  4 tons sounds like an awful lot of compressor for 1000 SF.

Chris


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## Jerry_NJ (Jun 30, 2008)

I think NW Ontario may need more BTUs for heating.  My 4 ton is for 2,000 sq ft, two story built for all electric and worse case 0 degrees outside.  At the design limits the 4 ton heating will require at least periodic cut in of resistive heat, it has two stages of that, which also serves as emergency heat.   In any case, I agree 4 tons sounds like too much for 1056 sq ft, but maybe not for Ontario.


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## Highbeam (Jun 30, 2008)

And not in 1978.


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