# New geothermal install



## sesmith (Nov 10, 2011)

Just had a new geothermal (gshp) system installed recently and thought I'd put up some pictures for anyone looking into this.  We've heated out house with wood and or forced air oil  previously. Started out using mostly wood (wood stove in cellar), switched to oil for a few years back when it was cheaper (we installed a new furnace in 1987 and figured we needed to use it for a few years at least) and then switched back to wood full time a few years ago again, with the more recent addition of a solar air heater.  Injured my back badly enough (while working on my firewood supply) this summer to take me out of the wood heating business, so it was either dump money into oil, or look at alternatives.  We decided to bite the bullet on a geo system as our climate in central NY with it's cloudy cold winters and wet  soil is ideal for geo. Payback over oil in our situation should be about 7 years with the 30% federal tax credit factored in.

I started up by having an energy audit done on our place, resulting in me doing some rim joist air sealing, then found a geothermal installer who we totally trust knows his business.  He did a great job on the installation.  He's an engineer and is as meticulous with his installation as he is with his design calculations.  He did recommend replacing and reconfiguring our ducting, something I'm really glad we decided to do.  The system works great and keeps our place within a degree of the set point with absolutely no cold spots...a far cry from when we heated with wood or oil.  We've only had the system in for a very short time, but have had temps down into the lower 20's, so far, before this recent run of beautiful weather.  It's also incredibly quiet, which probably wouldn't have been the case with the existing duct configuration.  Should also supply approx. 60% of our hot water.

Unit is a  3 ton climate master tranquility 27 with a ground loop consisting of 3x 600' lines (300' out and back) buried in approx 200' trenches.  Even though I was prepared for all the digging, you really don't appreciate the magnitude of it until you actually see it up close and personal.  Wasn't really too big a deal with us as most of the lines were buried in our horse paddock with a feed and return line to the manifold trenched out from our house across the driveway to the paddock.  Someone with a manicured lawn might have a different outlook.  To me, it just means less mowing for a while.

So I'll attach some of the during and after outside pics to this post and some interior pics to a reply.

Scott


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## sesmith (Nov 10, 2011)

Interior pics.  Oil furnace before (you can see the feed lines for the geothermal through the foundation wall at the side of the furnace) and a couple of after pics.


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## begreen (Nov 10, 2011)

Thanks for posting sesmith and congratulations on the new install. Tell us more. Is there supplemental heat or is this it? Can I ask what it cost for the project?


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## SolarAndWood (Nov 10, 2011)

Very nice.  I have wondered if geo with a net meter PV setup might be the way to go.  While I think about it, I will keep stuffing the steel box and try not to get hurt feeding it.


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## Jack22 (Nov 10, 2011)

Very cool stuff. I have always been interested in geothermal systems. Do you run water with antifreeze through the loop in a system like this?


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## nate379 (Nov 10, 2011)

Can you explain a little how that works?


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## maple1 (Nov 10, 2011)

I've also been considering geothermal for our heating system overhaul, but think I have pretty well decided against it.

Not sure what your costs were, but here I think it would be right around the $20k mark - plus any duct work or related heat distribution setups, and then having to re-do the landscaping. We've got a 2 story with all baseboard, so would have to basically put in a whole new heating system to go geo - new ductwork & all. We'd likely be at around $30k, maybe - with increased electricity bills to run it. The operating cost is something I'd like to get a better handle on before I completely rule it out - hopefully after this winter I'll have some decent info on that from a couple guys here who have gone geo. I'm thinking it would be at least an extra $100/month, likely closer to $200. If I don't do that, and put in a new wood/oil system (at around $10k), my total operating costs should be less than $50/month, that's mostly for DHW. Maybe even down to $20 by spending another $1500 or so for heat pump water heating, or even less if I can light a wood fire every week or so. With free wood, it's hard to justify the outlay for geothermal plus increase operating costs - although the easy turn key clean operation is certainly attractive. I'm thinking (hoping) by the time I'm not able to do the wood thing anymore, technology will have improved to where it won't hurt as much to move away from wood - until then I have pretty well decided to take advantage of the free wood thing as long as I am able.

Keep the info coming, it is certainly useful & appreciated. Good luck & keep us posted.


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## sesmith (Nov 10, 2011)

I'll try to do a quick reply to some of the questions.  First to all the wood heaters...keep doing what you're doing.  It would be hard to find a way to heat your house any cheaper, especially if you cut your own wood, although operating expense wise, not considering installation, the geo unit will cost less to run, in my area, than if I bought firewood.  I'd still be heating with wood...in fact my wood supply that was designated for this year is still out in the woods cut and bucked where I left it.  I was starting to look at alternatives anyhow.  I thought that cutting and splitting the usual 6 cords might get old by the time I got to my 60's.  I had a good run of cheap heat going, though.

This system uses glycol in the coolant loop underground.  The coolant comes in at around 52 degrees currently and leaves the unit at around 46 degrees (in 1 stage heat).  That 6 degree temperature difference collected from the soil gets turned into about 90ish degrees (measured at my closest air duct to the unit).  It does this first, by moving a lot of coolant through the ground loop, and then using  a refrigerant loop in the unit, which boosts the temperature using the phase change properties of the refrigerant, much the same as a refrigerator takes the heat out of the inside of the refrigerator and puts it into your house.  All this is done at about 400% efficiency, so for every 100 btu equivalent of electricity you use to run the unit, you get approx. 400 btu out in the way of heat.  This is true when you are running on 1st stage heat.  The compressor in the unit is is 2 stage, so if it needs to put out more heat than you get in stage 1, it will move on to stage 2, but be less efficient there.  There is also an auxiliary electric resistance heater in the unit, that can be used to supply more heat, or be used as a backup if the unit breaks, but at a much higher cost of operation.  The aux heat can be locked out by using the outside temperature sensor I have installed, so, for instance, you can program the tstat to prevent aux heat from coming on unless the the outside temperature is less than, say 20 degrees.  This prevents aux heat from coming on if you were to bump the tstat up a few degrees and the unit attempted to raise room temperature quickly.  Basically, everything in the tstat is programmable, so the system can be tweaked to be as efficient as possible minimizing stage 2 and aux heat while maintaining a set temperature in the house that is very stable.  During the summer, the system can be run to remove heat from the house and put into the ground.  AC is  not important for us here, but there are times when it's nice.  There's also a water heating circuit in the unit tied to a 60 gal storage tank that will supply up to 120 degree water at little cost.

Cost of the unit was 24k.  The federal tax credit will bring that down to 16k net.  A huge amount of money for a heating system, but using $3.62/gal oil prices (which is conservative) and $0.12 kw hr electric rates (most recent bill was $0.116 including delivery, misc fees and taxes), the initial installation cost should come back to us in savings over oil heat within 7 years.  It will also add some value to the house, though currently NY state cannot increase your tax assessment due to geo or solar energy installations (so the laws say, anyway).  This is not even taking into consideration the aesthetics of having a clean heat source, less work, and much cleaner inside air quality in the house.  Of course, the true picture will be obvious come Jan-Feb.

I also still have my wood stove in case the power goes out...or if I miss it too much.


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## sesmith (Nov 11, 2011)

maple1 said:
			
		

> I've also been considering geothermal for our heating system overhaul, but think I have pretty well decided against it.
> The operating cost is something I'd like to get a better handle on before I completely rule it out - hopefully after this winter I'll have some decent info on that from a couple guys here who have gone geo. I'm thinking it would be at least an extra $100/month, likely closer to $200. .



Here's a link to a good xcel calculator from the EIA  that may help you get a rough idea of your operating costs.  It takes into consideration heating efficiency as well as combustion efficiency of the various heating options out there.  You can fill in local costs of the fuels and adjust the efficiencies, if necessary, to match your equipment.

http://www.eia.gov/neic/experts/heatcalc.xls


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## nate379 (Nov 11, 2011)

Interesting setup!

I'm not sure anyone has done it up here.  The frost line is about 10 ft so it would require some deep trenching or maybe going straight down like a water well?


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## sesmith (Nov 12, 2011)

NATE379 said:
			
		

> Interesting setup!
> 
> I'm not sure anyone has done it up here.  The frost line is about 10 ft so it would require some deep trenching or maybe going straight down like a water well?



Thanks.

Here's an interesting (but long) read on geo in Alaska:

http://www.google.com/url?sa=t&rct=...kZymAw&usg=AFQjCNF-5-QUACftRJ3Py0PmsQSXf_2_SQ

 A couple of quotes from it:

"Alaskaâ€™s GSHP industry is small, but recently has shown growth, with some prominent commercial
installations in Juneau and several residential installations in Fairbanks. One large-profile commercial
GSHP system has recently been installed at the Juneau Airport Terminal. "

"Residential GSHP owners interviewed for this report had installed a GSHP for a variety of reasons, but
each homeowner reported that long-term cost savings was a strong motivation. Some homeowners
found their systems to be low-maintenance, and more than one homeowner installed a GSHP in part
because it is a partially renewable-energy technology. All of the residential GSHP owners interviewed
reported satisfaction with their systems."

"No drilling companies in Alaska were identified that can drill boreholes cheaply enough to compete with
horizontal systems. The high cost is due to a combination of ground conditions, limited competition, and
available equipment."


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## semipro (Nov 13, 2011)

Nice system.  You're going to love it, especially after you pass the break-even point.  

You mentioned that the duct system was quieter.  Geo systems are nice too in that you have no noisy outside condenser unit.  

Too bad they can't figure out a less intrusive method for installing the heat exchange tubing underground.  Maybe someone has.  Our Geo is an open loop system that uses our drinking water well.  I've considered converting to an in-ground loop system like yours.


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## johnny1720 (Feb 21, 2012)

Can you give us an update on this?   

I just had a 4 ton ClimateMaster 27 series installed last friday.

It is warmer in this house than it has ever been.


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## sesmith (Feb 21, 2012)

johnny1720 said:
			
		

> Can you give us an update on this?
> 
> I just had a 4 ton ClimateMaster 27 series installed last friday.
> 
> It is warmer in this house than it has ever been.



Congrats.  Saw your pics on the geo forum.  

Update on mine.  It's been a warmer than average winter here in central NY, as you know.  We have had a couple of below zero nights though, to test the system.  It works just as it was designed.  As the outside temp drops into the single digits, the heat pump will go into second stage operation.  Usually, by the next morning, it will still be in second stage with the aux heat coming on periodically to help out, at those temps.  The system was designed with a balance point of 7 degrees and an interior set point of 70 degrees. We like it at 67, so operation is right in line with it's design, maybe a little better.  Right now, the incoming loop temp is around 38-39 degrees, so the loop is also working as designed (avg loop temp target was 40 with a minimum of 32).  Best of all is my electric use.  The geo system cost me about $35 to run for the month of Nov., about $65 to run for the month of Dec, and about $75 to run for the month of Jan (this is the electric use over my average, which was pretty consistent over the last year or so).  Even if NYSEG managed to double my electric rate (which has been around  10-11 cents per kwh lately) it would still be a bargain to heat with.  No complaints here.  Better than spending 3k on oil, and I still haven't burned my wood stove this year, but the chimney's clean, just in case.


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## Ehouse (Feb 21, 2012)

I have a system sitting on pallets in my garage waiting for the bucks to finish the house shell.  It's a bit different so I'll describe it.  This is a closed loop pond set up (8' depth is sufficient in central NY) with minimal excavation required, just 2 trenches from house to pond.  The main heat pump unit is water to water and feeds high mass radiant floors throughout the house.  It will handle about 3/4 of the heating load for the coldest expected temps.  When this capacity is exceeded, a second unit, which is water to air kicks in for aux. heat.  It is hooked up to the air handler containing an HRV and can also supply AC and DHW.  The floor temps are projected to operate at 81 degrees F.  

Higher efficiencies are purportedly obtained with DX (direct exchange) where the refrigerant it's self runs in the collection tubing and cuts down on excavation in ground loops.  


Pricing is all over the place so shop around.

Ehouse


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## johnny1720 (Feb 22, 2012)

We have only been down to 17 degrees one night, I am actually really looking forward to a good cold snap.  I want to see what this system will do.  I only had my unit in stage 2 once, I had closed a damper in the same room as the thermostat, it was 75 in the rest of the house and only 70 in the room where the thermostat is located.  That is encouraging to see such low numbers for heat cost.  I know I will not be nearly as lucky as you, I expect to pay at least 200 each month in addition to the normal electric bill (during heating months)


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## Jerry_NJ (Feb 22, 2012)

I've been running a 3 ton Water Furnace geo unit for close to 20 years.  Interestingly the efficiencies seem to still be competitive. My unit delivers COP of 4 in low speed (the most efficient speed) and about 3.5 in high speed (that at 36K BTU output).  I have a dual vertical loop which puts a lot of exchange in the water table.  The COP of 3.5 is with a ground loop at 32 degrees, I think it has never been close to that cold.  It was maintenance/repair free for about 15 years, I have since put about $3k into replacing some of the rotating machinery, the compressor has not been replaced.  

We are a bit higher on electricity cost at about 16 cents per KWH, but still the geo HP is lower cost heat than hardwood purchased at about $220 a cord.  However, I use about two cords of wood a year, in part because I like it and in part when it is real cold I like to give the ground loop a rest to recover.  When I have the wood insert going I keep the hp off for several hours, usually 10 to 12 hours.  I believe that helps get the COP up a bit when the HP comes back on line.

I think mine has paid for itself, but it was not more economical in than oil in its early years, here electricity was bout 10 cents a KWH and I think heating oil was about $1 a gallon.  Heating oil has tripled in cost while electricity has gone up about 60%.  I do worry however when ever I remember the threats I've heard "electric rates will necessarily sky rocket", but the fact that congress refused to pass the cap and trade has made the geo HP the most economical way to heat, cool too, it has an EER of about 20.  

I checked the Water Furnace web site and see they are advertising a COP of 5 in their best unit.  I know there are a number of improvements in compressor design that my old unit does not have.


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## sesmith (Feb 22, 2012)

johnny1720 said:
			
		

> We have only been down to 17 degrees one night, I am actually really looking forward to a good cold snap.  I want to see what this system will do.  I only had my unit in stage 2 once, I had closed a damper in the same room as the thermostat, it was 75 in the rest of the house and only 70 in the room where the thermostat is located.  That is encouraging to see such low numbers for heat cost.  I know I will not be nearly as lucky as you, I expect to pay at least 200 each month in addition to the normal electric bill (during heating months)



FWIW, my numbers don't include the fact that the system offsets some of the water heating done by my electric water heater with the desuperheater, so the cost to run the geothermal has to be at least a little more.  Still, as far as I'm concerned, the bottom line is how much more electricity I'm using at the end of the month total.  Also, we have a small house that I've done a lot of energy upgrades to over the years, and we like it on the cool side.  I think if it ever got up to 75 in the winter, I'd switch the thing over to "cool".

 It will be interesting to see how things work out when we get a real winter, but even so, I'm really impressed with the system.  The fact that it keeps the house within a degree of the tstat set point, and all the downstairs rooms are within a degree of each other in this old house is amazing.  67 with this system feels fine while 67 with the old oil furnace felt cold, but we rarely set it any higher because of the cost of oil, and set it way back at night and in the day when we weren't home.  When heating with wood, my kitchen area was usually 70ish and my living room probably more like 65.  so we feel spoiled this year.  I know what you mean when you say your house has never been warmer.  Strangely, the hardest thing we have had to get used to is that we really do like it even cooler for sleeping and it's been almost too warm.  I tried a 1 or 2 degree setback earlier in the year, but found that as the weather got colder, the system works pretty hard to bring the house back up to temperature.  Didn't seem worth the trouble, so we just leave it set at one temperature and close off our bed room registers at night.  Actually kind of a hard thing to get used to as the setback thing is so ingrained from many years of doing it, and wood heat sets itself back by morning, especially if you oversleep.  The geo heat also doesn't dry the house out like the other heat sources we had, and the system really does a good job of filtering the air in the house.  I'm sure you'll like yours.


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## sesmith (Feb 22, 2012)

Jerry,

Glad to hear of a 20 year old system that's been pretty trouble free.  3k over 20 years is  probably less than you'd spend on routine maintenance on an oil furnace over that time, not including repairs, and the oil furnace would be getting close to replacement time.  That's really the only unknown at this point.  Hope I have as good luck with mine.

Your picture of Montana reminds me of my 12 year old golden who is laying down next to me right now.  He's showing the white face yours had in the pic and doesn't move as fast as he used to, but neither do I.  Good dogs age too fast.


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## sesmith (Feb 22, 2012)

Ehouse said:
			
		

> I have a system sitting on pallets in my garage waiting for the bucks to finish the house shell.  It's a bit different so I'll describe it.  This is a closed loop pond set up (8' depth is sufficient in central NY) with minimal excavation required, just 2 trenches from house to pond.  The main heat pump unit is water to water and feeds high mass radiant floors throughout the house.  It will handle about 3/4 of the heating load for the coldest expected temps.  When this capacity is exceeded, a second unit, which is water to air kicks in for aux. heat.  It is hooked up to the air handler containing an HRV and can also supply AC and DHW.  The floor temps are projected to operate at 81 degrees F.
> 
> Higher efficiencies are purportedly obtained with DX (direct exchange) where the refrigerant it's self runs in the collection tubing and cuts down on excavation in ground loops.
> 
> ...



Sounds like an interesting setup.

I'm not so sure of the higher efficiency claims of the DX systems, but I'm certainly no expert.  It seems to me that you're only going to get so much heat out of an area of ground, so the fact that they use smaller loops just means they have to operate at lower temps so they have to be a little more efficient to pull that off.  So a ground loop water to air (non-DX) just has to pull the heat from a larger loop.  Big deal??  Either way, I wonder if operating costs are really any different at the end of the year.  Personally, I'd rather keep the freon circuit in the house.  Seems likely to be more trouble free that way, but I'm sure the DX fans would see it differently.


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## Ehouse (Feb 22, 2012)

I'm unsure of the claimed efficiencies of DX also,  but semipro, I think, was asking about improved ground loops.  I think the refrigerant has to go in copper lines for DX.  Using slinky or coiled loops is another option but may also run into the problem of over taxing the ground collection area.  I think it is less of a problem for pond or open well loops as the moving water can more readily recharge the collection area.  When I was figuring out my system I was thinking of using the area beneath the house ( vertical boreholes with slinky loops) to utilize the foundation excavation.  The rough calculations I did indicated this would work, and I intended to run a couple of extra lines outside the footer for good measure.  Aside from the space and excavation saving aspect if this kind of install,  the house itself would insulate the collection area allowing it to recharge faster.  I got some negative feedback from Professionals helping me with the design who said this had been tried in Sweden with poor results, but that's Sweden.  I think it could be designed to work in a more favorable clime.  Unfortunately, (or not) I ran into bedrock just below my footer,  and the pond was handy, so I followed the POLR.  This is all important emerging technology and it's good to hear people's experiences with their installs, good and bad.  Any one have a DX loop?

Ehouse


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## DickRussell (Feb 22, 2012)

In any GSHP system, there is a heat exchange system on the ground end. Heat is transferred between the ground and whatever fluid is circulated between the heat pump and the ground loop. Usually the fluid is water, perhaps with glycol in it for freeze protection, but in a DX system the fluid is the refrigerant itself. In almost any heat exchanger, there are three separate heat transfer coefficients. There is one for the fluid being circulated (call it Uf). There is another for the ground itself (call this Ug). If there is a tube wall (plastic or copper) through which the fluid flows, there is a third coefficient for heat transfer through the tube wall (call it Uw). This third coefficient is absent for a Standing Column Well (SCW) design, in which well water circulating between the heat pump and the well is in direct contact with the well bore. The overall heat transfer coefficient (U) is calculated from:

     1/U = 1/Uf + 1/Ug + 1/Uw

The value of Uf depends on the fluid properties, its velocity through the tube, and the tube diameter. The value of Ug depends on the thermal conductivity of the ground material and in the case of packed soil is strongly affected by both how wet it is and how tightly packed around the tube it is. The value of Uw is calculated directly from the thermal conductivity of the tube material.

In a DX system, the vaporizing or condensing refrigerant has a very high heat transfer coefficient, relative to that of a flowing liquid. Furthermore, in a DX system, there is no need for a heat exchanger in the inside portion of the overall loop to transfer heat between refrigerant and circulating fluid, because the refrigerant IS the circulating fluid. Also, the tube in a DX system, being copper, is far more conductive than plastic, so that Uw is much higher. Both Uf and Uw being much higher in a DX system tend to make the length of tubing that much shorter.

Then we come to the heat capacity of the chunk of ground in contact with the copper tube and the comments by Ehouse regarding overtaxing the ground collection area. It may be one thing to have a shorter coil in a DX system, [edit: due to] higher overall heat transfer coefficient. After all, the heat transfer rate is given by Q = U*A*dT, where A is the tube area and dT is the temperature difference. Initially there will be a higher rate of heat transfer, but removing heat from the ground next to the tube depresses the ground temperature in heating mode or raises it in cooling mode. The temperature difference drops accordingly, and that reduces the heat transfer rate. As the temperature of the ground next to the tube goes up or down, heat is transferred to it from the surrounding soil. Given a long enough run time, some quasi equilibrium point would be reached, which ultimately determines overall heat transfer rate and thus the system capacity. Hopefully there is enough ground in the vicinity of the tube to provide heat through the heating season.

Even though a DX system ought to need much less tube length, due to the higher overall heat transfer coefficient, success of the design does depend either on having enough mass of ground in the immediate vicinity of the tube (perhaps enough tube length) or on the existence of a different mechanism for bringing heat back to the ground around the tube. Having the copper tube in a drilled hole in rock is better than having it in dry sand, obviously, owing to the much higher conductivity of solid rock. If the tube is in a flowing aquifer layer, the flow of water past the tube (even if the flow is slow through a soil layer) takes care of the heat recharge issue. Without such a recharge mechanism, not dependent on slow conduction of heat through the ground, the copper tube may have to be a lot closer in length to what would be required for water through a black plastic slinky to gain access to enough heat for the long haul. In that case, the volume of refrigerant needed to charge the loop may be prohibitive. There is no one size fits all solution. DX can be a good solution for the right physical situation. It's not best for all situations.


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## Ehouse (Feb 22, 2012)

Thanx for that!

So for a ground loop with no special recharging capabilities, DX will require less tubing if spaced correctly, but draw no more heat from a given collection field, eh?

What might happen if you placed a DX loop in a spring out flow or the tail wash tube from a pond stand pipe, say after a micro hydro turbine in the drop tube?  Or a silo or ensilage bunker or a manure pit?

Ehouse


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## Jerry_NJ (Feb 23, 2012)

One of the reasons, no equations written or calculations made, I use my airtight wood insert to heat is to give the "ground" look time to recover.  I intuitively concluded that on real cold weather when the HP is running at least 60% of the time, making it shut down for 10 to 12 hours by using wood to heat helps the loop recover.  These wood heat run are mostly after dark, when we have lost the benefits of solar heating.  That said, have a wood fire too because I enjoy the sight and feel of it, albeit that requires I'm neat the fireplace insert.  My HP is efficient enough that it gives me more BTU/$ than does wood, and it heats the whole house to a near equal temperature.   The HP does have a low speed fan setting which I leave on 24/7, and that helps some with distributing the heat.  Having a two story home (not large, about 2,000 sq ft) with a central open staircase, and large door (arches) between the living room's fireplace also help move the warmed air around.

The discussion above suggests my goal of giving the ground loop time to recover is reasonable.  I have two vertical loops and that extend well into the aquifer from which we pump our drinking/house water, so I know the loop benefits from the water table, perhaps enough that my recovery strategy is of no benefit.  I enjoy the wood fire anyway, and at least when I have it fired up the HP is off other than the circulation fan.


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## sesmith (Feb 23, 2012)

Interesting current thread on DX systems here:

http://www.greenbuildingtalk.com/Forums/tabid/53/aff/13/aft/79832/afv/topic/Default.aspx


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## woodgeek (Feb 23, 2012)

sesmith said:
			
		

> Interesting current thread on DX systems here:
> 
> http://www.greenbuildingtalk.com/Forums/tabid/53/aff/13/aft/79832/afv/topic/Default.aspx



I think that thread summed it up well refrigerant (DX) versus water/glycol loop.  I think the soil side 
thermal conductivity has to be limiting in most cases (except in aquifers that are slowly 'flowng').  So 
the higher eff claims need to be based on side by side field reports.  I could believe that there is
less pump work if the refrigerant is lower viscosity.

Personally, the heart of all these systems is the compressor, and the key to longevity is keeping
foreign matter out of the compressor wear surfaces and keeping the oil in the motor.  It seems that
many of the problems (at least with ASHP) are from sloppy installers letting contaminants into the
refrigerant loop lineset.  So, I would be much happier with my refirgerant loop being contained in
a factory sealed unit, rather than running through 100s of feet if field installed tubing.


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## Ehouse (Feb 23, 2012)

google Heatgreen home heating for another interesting read.  

I wonder if a Trombe wall or solar water heater loop hooked into a system and used on sunny days would give a ground loop time to recharge?

Ehouse


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## DickRussell (Feb 23, 2012)

woodgeek said:
			
		

> sesmith said:
> 
> 
> 
> ...


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## woodsmaster (Feb 25, 2012)

Do the fans run all the time on these systems ?  I recently worked on a house with geothermal and I don't think I ever heard
the fan shut off.


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## Jerry_NJ (Feb 25, 2012)

My system has a two speed fan, the lowest speed is very quiet, but it can be heard.  Even the high speed isn't noisy.   The fan also has a third lower/slower speed that can be set for continuous run at the thermostat.  I turn that off when I am not heating or cooling... even if I have the system on but don't expect to see much run time.  The installation recommendation was to leave the fan on all the time and leave the HP on all the time in the automatic mode, it cools or heats based on settings and "never" needs to be touched again.  I have a hands-on guy, and we like the windows open when the weather permits, so in the spring and fall the HP is completely off, including the low speed circulation fan.  This fan is a plus when I'm doing serious wood heating, it help s move that heat around the whole house.


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## sesmith (Feb 25, 2012)

woodsmaster said:
			
		

> Do the fans run all the time on these systems ?  I recently worked on a house with geothermal and I don't think I ever heard
> the fan shut off.



They do work differently than a conventional heating system in that they're sized much more closely to the heating needs of the building, instead of being over-sized, as are most conventional systems.  They also put out cooler air.  So as the temperature outside drops closer to their lower design temperature, the system runs more and more of the time in a given hour, until it's on all the time.  Long run times like this are actually a more efficient way for them to run, and doesn't mean that they are having trouble keeping up (so long as the system is sized correctly).  What this does do, is keep the house temperature very even.  Mine rarely is any different than the set point I have it set to.  It also has a variable blower on it and a 2 stage compressor to further control things.

My system will start running continuously at temps around 15 degrees or less, give or take.  When it goes into the single digits, second stage will kick in as well.  Usually in the early morning after a night a little below zero, the aux strip heater will come on for a few minutes periodically, to help the system out ( which will also be running in second stage).  This is a system with a winter design temp of 2 degrees and a balance point where aux heat may be needed of 7 degrees.


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## woodsmaster (Feb 29, 2012)

Thanks for the info I wondered about that. Seems like a lot of elec. to run the fan all the time. The house I was working on was medium in size and he said he had around a $300.00 elec. / month for 2 adults and a baby. I circulate water, have an old house andfamily of 5. My elec bill is less than $150.00 / month in the winter, but I also burn a cord a wood a month in the winter and a little in the summer for hot water. In the summer my bill goes up to 200.00 or a little more becouse of the air cond.


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## woodsmaster (Feb 29, 2012)

Don't get me wrong I Like geo thermal and it's much more convienient than burning wood. I just don't like air blowing around.


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## Jerry_NJ (Feb 29, 2012)

On my geothermal I can set it so the fan runs only when heating or cooling, the "run all the time" is my choice.  And, when using my wood stove (fireplace insert) the HP fan running all the time help distribute the heat that is building up in the room with the stove - a big plus.  With the duct work I have the noise of the fan in low speed is almost imperceptible.  

I agree with the practice of not "wasting" energy, and that is why I set the fan to run only on heat/cool when I don't want to circulate air around the house.  In fact there are several months a year, suppose at least 4, that the HP is completely off.  P.S., goe or air-to-air, a "super heater" exchanger with the water heater turns air conditioning (cooling) wasted heat into hot water, great, this is truly "free" hot water... assuming one is air conditioning anyway.


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## sesmith (Mar 1, 2012)

woodsmaster said:
			
		

> Don't get me wrong I Like geo thermal and it's much more convienient than burning wood. I just don't like air blowing around.



I see you move your heat around in liquid form.  That works too.  The air blowing with our new system is almost unnoticable.  Very quiet, but we also replaced and reconfigured all the ductwork when the system was put in.  Its quieter than all the fans I had running when we heated with wood.  Our old forced air oil furnace was a dust maker.  When the sun was right, you could see all the dust being blown around when it came on.  The new system has a large merv 11 filter in it, so it works as a whole house air filter as well.  FWIW, I couldn't buy firewood at $200 / cord (going rate here) and heat the house for less than this system costs to run. ( I  never did buy the wood, though, when I did heat with it, as ours came from our wood lot...saved a lot of money that way).


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## johnny1720 (Mar 2, 2012)

I have been watching the forecast like a hawk lately.  There is no cold snap in the near future. We have had daytime temps in the mid 30's to mid 40's.  We are only getting down into the 20's at night.  I have been reading my meter almost every day and we are using about 58kw per day which is an increase of about 18kw per day.  So that means I am paying about $2.00 per day to heat the house when it an average temp of 34.  I cant burn my pellet stove for less than $8.00 per day.  I need to burn at least two bags of pellets @ $4.00 per bag.  

So far so good with this investment.


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## Jerry_NJ (Mar 2, 2012)

Looks good, congratulations.  But, what?, 58KWH per day, or 40 KWH when you were not heating with electricity. That's a lot of "background" power consumption.  $2 for 19KWH, that's 11 cents per KWH, wish were were that low, Jersey Central Power is charging a bit over 16 cents per KWH.  It seems you too are all electric.

Or temperatures here in North Central NJ are a bit warmer than yours, but only a few degrees.  Looking back to colder weather, more like you are having now, I'd say we were using about 45 KWH per day, including heat.  Now we are all electric, including hot water, cooking washer/dryer, refrigerator, well... lights, the only other "utility" bill we have is telephone (and TV/Internet).  And, yes, I burn a cord+ of season hardwood a year which cuts back on the KWHs on those months that I burn wood.  Some of this wood is scavenged, included from my property, so I can take the work as exercise and conclude that wood is free less the cost of gas and wear and tear on my equipment. 

In any case you are having the same experience I am having, I use wood for reasons already stated, not to save money over the cost of geothermal heat.


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## johnny1720 (Mar 2, 2012)

Yea 40kw is what I usually use per day.  My electric rate was the 17 cents an hour then I got talked into to using an alternate energy supplier.  Then it dropped to the 11 cents.  I have a well that is 60 feet deep/electric range/electric dryer and now my heat is 100% electric.  I am going to have my well looked at and see if that is drawing when not being used.  I have always thought it might be but I never had a way of checking.


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## Ehouse (Mar 2, 2012)

I had that problem with my well, turned out to be a crack in the pipe just above the check valve on the pump allowing the water to drain back and lose pressure.  Look at your pressure guage and see if it holds steady after the pump stops.

Ehouse


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## Jerry_NJ (Mar 2, 2012)

Right, with a deep well there is always (as far as I know) a holding tank that has a trapped air chamber which compresses when the pump is supplying more water than is being used (normal, in my case I can have the garden hose on full blast and the pump still cycles at about a 50% duty cycle).  When the upper pressure limit is hit, the pump should shut off.  As noted, there should be a pressure gauge and you should be able to see it pump up, stop, and leak down (assuming you have something on, say the kitchen faucet).  Of course, with no use of water, the pressure gauge should just set at a reading, not moving up or down.

My well is about 100 feet and the pump is 220 Volt (telling outright it uses a lot of power).  I think it is about 1 HP, or in the neighborhood of 750 watts.  That is 0.75 KWH per run hour.  If I assume only 500 watts, that running full constantly would run the meter up 12 KWH per day.  In any case check it out,  but I consider it unlikely that your pump is running all the time.  You didn't mention how many people live in your house, how good people are at turning off lights, and if you're using tungsten bulbs, not CFL or other high efficiency lights.  Lots of baths, laundry, dish washing and lights will put a lot of KWHs on the meter a day.

As for electric rates, I too buy from a third-party supply, cuts a few 10ths of a cent per KWH off my bill, and that cost is in the neighborhood of 11 cents per KWH, bur I also pay about 5 cents a KWH for delivery, thus the cost is 16 cents per KWH.  That's the way it works everywhere the electric power market has been opened to competition.  There is still no competition for the delivery system, all the money invested in wires/transformers/repair-crews... so even if one buys power from the (traditional) supplier, they will still see a charge for generation and one for delivery.  Compare their generation cost with the cost of a third party supplier, don't compare the 3rd party supplier cost to your old total cost per KWH.

Edit: corrected 7.5 KWH to 0.75 KWH in second paragraph.


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## sesmith (Mar 2, 2012)

johnny1720 said:
			
		

> Yea 40kw is what I usually use per day.  My electric rate was the 17 cents an hour then I got talked into to using an alternate energy supplier.  Then it dropped to the 11 cents.  I have a well that is 60 feet deep/electric range/electric dryer and now my heat is 100% electric.  I am going to have my well looked at and see if that is drawing when not being used.  I have always thought it might be but I never had a way of checking.



Find someone with a multimeter with a clamp on amp probe on it, who is familiar enough with electrical work, to check for a draw on the pump circuit.  This will have to be done from inside the main panel.  There should be no current draw when the pump's not running.  It wouldn't be a bad idea to check any of your circuits that have wiring run underground.

Another thing you might try is to buy a "kill-a-watt" meter, to use around your house to check all your plug in appliances.  It can be a real eye opener.  I found out just how much electricity was used by our stock tank heater a couple of years ago.  I've since built a superinsulated horse watering tank that cut that usage almost to zero.  I also found that our old dehumidifier in the cellar was using a lot of electricity and basically wasn't doing much of anything for the humidity...since replaced with a much more efficient one.  Those 2 changes cut our electrical use by a third.


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## johnny1720 (Mar 3, 2012)

sesmith said:
			
		

> johnny1720 said:
> 
> 
> 
> ...



I have had a kill-a-watt meter for over 5 years.  I have a huge spreadsheet with appliances listed and how many KW they use.  Previous to me replacing my electric hotwater heater with a propane tankless I was spending almost almost $250 per month on electric.  I do have an amp meter at work with a clamp on it I should bring it home and try it.  

I think the culprits are

-my dryer seems to only dry on high
-my well is below grade (water shoots out of the top of it)
-I have an old double door fridge that is not in the best shape, i have not ran the KW meter on it yet.


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## woodsmaster (Mar 3, 2012)

Is it possible to have geothermal radiant slab heat ?


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## pdf27 (Mar 3, 2012)

woodsmaster said:
			
		

> Is it possible to have geothermal radiant slab heat ?


That's the recommended method of installing them, at least in Europe. Standard advice over here is that they're only marginally worth installing if you don't use radiant floor slabs!


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## Ehouse (Mar 3, 2012)

Radiant slab heat?  Most definitly.  The key factors seem to be high mass, super insulated shell, well insulated slab (edges and under) and high flow rate through the tubing.  As an example, my home (under construction) has a design floor temp. of 81* to maintain 68* in the living space for 3/4 of the expected highest demand conditions.  A second unit (water to air) will provide extra heat as needed as well as cooling and DHW.

Ehouse


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## woodsmaster (Mar 3, 2012)

pdf27 said:
			
		

> woodsmaster said:
> 
> 
> 
> ...



 Then it seems to me that would be the best way to go if building new. A lot less electric to circulate water around then to blow air.
Most folks over here do the air method probably for the ease of adding central air.


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## Jerry_NJ (Mar 3, 2012)

Slab heating ain't for crap at cooling (air conditioning), that's what a heat pump is all about, moving BTUs both ways.  Forced air provides a central means to filter the air and a means to transfer heat and cool to all rooms, upstairs and down.  If one can afford both, then a radian slab could be a nice addition, but more economical to heat?  I doubt it.

Johnny you haven't said what your needs are. How many square feet are you conditioning, how many people, how much cloths drying...  50 KWH per day in the cold days may not indicate any real losses.  Your usage doesn't seem overly high unless you are living alone in a well insulated house of less than 1,500 sq feet. 

You can see what the house is using when it is supposed to be off by watching the meter.  If you have an older analog electric meter it has a rotating disk, for most, mine, one rotation is 7.2 watt hours.  A digital meter must also have some sensitive readout.  Turn off you heat, make sure the hot water heater is off, better too, unplug the refrigerators/freezers, turn of the TVs.... most lights and go out and look at your meter.  If the disk I mention is rotating more than once in a couple of minutes (one per minute results in 60 x 7.2 = 432 WH) something is running that you should know about.  If you really shut down the house, the disk should just "creep" around... if you can get the house completely off, the disk should stop.

Again, 50 KWH per day for all energy uses isn't a lot.  Even at resistive heat 50 KWH is 170 KBTUs, someone using heating oil may be 110 KBU per burned gallon, or 1.5 gallons, at $350 that's $5.25.  At my electric rate of 16 cents per KWH $5.25 buys me 32 KWH.  Of course, most homes use more than 1.5 gallons per day in cold weather.  Just trying to develop a parallel to what 50 KWH represents.  With a heat pump you're getting way more than 170 KBTUs out of your 50 KWH.  I use about 45+ KWH a day in this moderate cold weather, and with 2,000 square feet two story well insulated I'll place the this provides at least 275 KBTU heating per day/night, or little more than half of my power consumption.


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## woodsmaster (Mar 3, 2012)

It certinly would be more economical to heat by circulating water. I'd be willing to bet it would Knock at least $50.00 a month
off most installs electric consumption if not more. It's the cooling that the slab isn't as good at.


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## johnny1720 (Mar 3, 2012)

Jerry_NJ said:
			
		

> Johnny you haven't said what your needs are. How many square feet are you conditioning, how many people, how much cloths drying...  50 KWH per day in the cold days may not indicate any real losses.  Your usage doesn't seem overly high unless you are living alone in a well insulated house of less than 1,500 sq feet.



-I am heating a 2400 square foot plank house that was built in 1860, when I say plank I say until I moved in and started remodeling there were not studs on the walls.  So if you can picture 18" to 36" wide planks going vertical between the floors on all outside walls and interior walls.  There are two layers of planks everywhere.  On the inside was plaster and lathe and the outside is tar paper and clap boards.  So the thickness of the walls was only about 4 inches.  I have since studded out more than 1/2 the walls and insulated and drywalled.  I have replaced all 38 single pane original windows with new vinyl replacement windows.  I also have about 45 inches of blown in insulation in the attic of my house.   I either burn 2.5 bags of pellets for $10.00 per day or I burn about 4 gallons of fuel oil for $16.00 per day. 

-There are 2 adults, 2 children ages 3 and 9 weeks.  

-Last winter was pretty long and rough, i burned 2.5 tons of pellets and 800 gallons of fuel oil.  The winter before that I used 650 gallons fuel oil and 2 tons of pellets.  And to tell you the truth this is a significant improvement from what I used to pay.  The first full winter I was in this home it cost me nearly $5000 to heat this place.  

-My hot water is heated via tankless on demand, I installed this 4 years ago (it has already paid for itself)

-Prior to Geothermal I was using about 40kw per day on average according to my electric bill, it has increased to about 58kw per day.  

-I have CFL bulbs almost everywhere, and all appliances are energy star including, dishwasher/freezer/beer fridge/old double door fridge which is also suspect.


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## Jerry_NJ (Mar 3, 2012)

Sounds like an interesting house, I am not familiar with the construction.  

Sounds like you've about got your arms around the heating cost and 58KWH a day for all what you said seems reasonable to me... indeed very good, and a way better than $5K in heating oil.  Seems heating oil (is that what you make hot water with) is $4 a gallon, the way gasoline is going I suppose heating oil is on its way up too, thank God spring is almost here.  

Does your HP have a hot water tap on the "super heater"?  You'd need a tank, but as you can see the energy gains running a heat pump are significant. Better yet, in the summer when you are throwing heat away (into you ground loop) any heat going into you hot water needs is free...just the cost of the tank.  I don't know how that would work with your investment in the "on demand" hot water, but if the tank was the feed to the on demand, the on demand would have to provide much less temperature rise, in fact none when the tank is full of 150 degree water, or whatever you HP is capable of generating. 

Keep up the good work and enjoy your investments in energy conservation while looking out the window at cold/hot weather.


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## johnny1720 (Mar 31, 2012)

I just wanted to update you all after I got my first electric bill,

The billing cycle was from 2/22 until 3/22, 29 days.  Last year I used 960 KW and I was charged $122, this year I used 1680KW and I was charged $176.  The price per KW hour goes down dramatically after 1500KW.  I know it was seasonably warm but I know if I was running my pellet stove I would have burned at least a 1/2 ton, and the oil furnace would have been running.  We had about 7 days were the night time lows were in the low teens.


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