Geothermal

Russ Bath, DX Manufacturer

In my training seminars I always state there are two things that the dealer must do correctly for a successful installation. They are:
1. Match the system to the load. This involves an accurate Manual J load calc. Then, identify how the system performs IN THAT EARTH TEMPERATURE. My company has performance charts for the equipment listing earth temperatures from 40 F to 80 F in 5 degree increments. This mistake will not happen using this method. A 4-ton system may produce 49,000 BTU in Atlanta but only 38,000 BTU in Boston. The mean earth temperature changes relative to latitude.
2. Make sure that the earth-loop contacts the earth. The loops will not perform sitting in a void underground.
ALL HEAT PUMPS REQUIRE SUPPLEMENTAL HEAT--even geothermal ones. They are not intended to perform down to the lowest weather bin temperature. Yes, they can provide down to the DESIGN temperature, but there is still 2-1/2% colder temps than that.
Dealers, read the manual. Stick to the manual. The adage, "I've been doing this 20 years." does not apply here. Unless you have been doing geothermal heating and cooling for 20 years, you have NOT been doing this for 20 years.
These systems work--consistantly and predictably, and they will PERFORM for you like a circus dog, but, if they are abused, just like the circus dog, they will bite you where it hurts.
I could go on....

AL_29

Geothermal

How many contractors are installing geothermal. Two years ago we started investing in this technology. Its been a huge payoff for us landing a $455,000 contract. And a few other $100 to $200 thousand dollar contracts. With the housing crunch we seem to be the only contractor hiring people. Problem is finding smart people. Any suggestions or comments.

kevin coppinger_4

too much...

money upfront. The customers (residential)are not willing to spend that kind of cash for a long payback....They are better off sealing the enveloppe w/ spay foam or ICF building products....

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Brian_11

question...

I have tried to get some info and training from water furnace, but they seem to want to only sell to one of my competitors. I have approached them at Comfortech with no success. I am curious to what brand you are selling??...where do you get the leads and wg=here did you go for training of geo??

Good to here you are doing well in these times.

Brian

mikea23

geo

Brian

We have installed geo for about 3 years now we install two manufacturers but for first time install I would recomend ECONAR in MIN 1-800-4econar good people great product and cust support is over and above. They make a cold climate heatpump so if your heating load is greater then cooling they would be my pick.

Mike A

tom_49

Al,

I too am very interested in geo. I think oil has to go a little higher (and it will)to start getting more people interested in geo on a larger res. scale.

Where are you located? what brand are you installing?

I have a couple of investor friends interested in starting a geo division at my company as well. Any advice?

Glad things are going good for you.

Tom

Blackoakbob

I have ..

been installing and selling heat pumps since 1975, all types, first air source, pump and dump, and as of late closed loop. The equipment is better and better easier to install and with the application of hydronics there isn't any place that won't benefit. The last closed loop I installed was heating the building with an amp draw of 19 and the house that I checked earlier in the day with an electric boiler was pulling 108 amps. I know you can't compare these systems so simply, but it shows the amount of energy to move heat rather than create it is less.
My preference is vertical loops in MN, but I always give the customer the option. My air conditioning sales are at least 50% heat pump. Best Regards,

Rich L.

GSHP

We also have had great success with GSHP's. We've retrofit 5 local schools with them. No it's not cheap up front. But the payback from the old outdated boilers has been incredible. The school system, not us, projected the payback to be 3 - 5 yrs. And as a huge bonus, none of these schools had air conditioning before.

Right now we are doing a local college residence hall.

On large projects like these we generally go with Climate Master. For residential (which we don't do) I personally prefer Hydron Module. I've used Econair as well and been pleased with it. It's a cold weather heat pump also.

For training one of the best organizations out there is the International Ground Source Heat Pump Assoc. You can find them at: http://www.igshpa.okstate.edu/ We are hearing of jobs that are requiring certification by them to even be allowed to bid. Also I feel some of the best bang for the buck training is at the Iowa Heat Pump Association's annual conference. It's held every March and the level of training provided is fantastic. This march will be my third time and I'm always picking up more info. There's also a trade show there with numerous manufacturers.
They are at: http://www.iaheatpump.org/iaheatpump/Events.aspx

The event schedule for training is: http://www.iaheatpump.org/iaheatpump/Files/2008Conferencetentativeschedule.pdf

One last note, the argument of them being too expensive up front just doesn't hold true as much as it used to. If you take the time to educate the consumer, and many of them have already done thier homework, they realize the potential payback is huge. In my area the spray in insulation costs twice as much up front as fiberglass and the installers can't keep up. Why? They've taken the time to educate the consumer and shown them the value in paying more for higher quality to begin with. It's no different than selling a Viesseman over a Munchkin. Both are good boilers but one costs twice as much as the other. are people still selling them? You better believe it! And as soon as you mention "green" people get very excited to jump on that band wagon!

Good luck, Rich L

hot_rod

Research and train!

More and more HVAC shops in my area are offering geo. But some skip the training and I now have two customers with under- performing geo systems (hydronic tie in.)

They miss or short change their design with the number of wells or amount of trenches needed. Hard to correct after the fact.

One DX owner can't even grow grass over his HX field.

hot rod

Craig R Bergman

Really???

In Eastern Iowa the installed cost of a water to air 4 Ton Geothermal Heat Pump, after rebates,is about $10K. A home that is about 2,000 Sqft will cost $50 to $100 A MONTH less to own, between mortage and utilities, than a home with forced air!!! Educate your customer and it is a no brainer!

Bergy

Rich L.

Training is key

We also have a shop in our area that consistantly "under installs" thier geo systems. A shop could make a living just following these guys around and redoing thier systems. Unfortunatly to the customer they can wind up with the mindset that this darn Geo stuff just dosen't work. That's a battle we all face in not cutting corners and doing the job right.

There's no question, an accuratly sized loop field is critical to system efficiency. Undersized will under perform.

kevin coppinger_4

where do...

the rebates come from? Maybe the labor rates are less in IA than here in NH....The contractor I have been working w/ on 3 proposals have not been able to convince anyone yet....kpc

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Rich L.

Rebates

The rebates in our area Kevin come from the electric utility, Alliant Energy. When I built my house last year I received a $3400 rebate from them. That was for the total package, tight envelope as well as GSHP. The rebate paid the entire cost of my unit, a 5 ton w-w.

Do you get involved with the contractor when he presents your proposals to the H.O.? That could help. The customer has so many decisions to make when building a new house and it can be a hard sell to convince them to go with the GSHP over the granite counters. A lot of them want the dazzle up front and they can't show off that loop field in the back yard to impress thier friends. If you can take the time to educate them up front it can make a big the difference. But it needs to be from you, not just the general and you have to be passionate. You can give them some websites to educate them too. It's the same thing we have to do with radiant and hydronics. It's going to cost more up front than scorched air, but you're going to get the payback as long as you're in your house with comfort and efficiency.

Wages in E. Iowa are generally running from $25 to $35 per hr depending on the shop.

don_185

True

Training is key.However you need to train on both sides of the equipment.That or get you a very good well guy that you can learn from.

Biggest complaint I know of with geo system.The customer does not know who to call.The well guy or, the hvac guy.

The problem I see from most hvac contractor and geo installs.They assume that geo can be install in any or all
envelopes.

Believe me they are great heat transfer devices however, they do have their limitations.






Anyone working with DX..direct exchange geo system?

Craig R Bergman

Correction

The installed cost of Geo after rebate is about $10k more than high effiecent natural gas furnace and 14 seer A/C.

Bergy

Craig R Bergman

What limitations?

A BTU is a BTU. The structure does not know how the BTU was produced! If we need 20,000 or 120,000 BTU's we provide the tonage of Geo needed!

Bergy

GMcD

Geo Limitations

The limitations are with respect to the temperature of the heating water and cooling water being generated from water to water heat pumps. One of the other big geo system training areas that is lacking is properly matching water to water geo systems with the right terminal heating and cooling systems. There are many flavours of geo systems out there, and clarity in terms of the HVAC system type is needed - there is geo-exchange serving a packaged "water to air" heat pump unit that blows hot and cool air around in the building, there is also water to water geo that allows one to use 120F and 50F water in many fun ways as well.

The key with any kind of geo-exchange systems is MINIMIZE THE BUILDING LOADS FIRST! Then the costs for the geo-field and plant equipment are reduced. Spend $$ on the building envelope FIRST, then apply geo systems if appropriate.

hot_rod

Two DX systems

I was involved in this past year. Both were a headache in terms of equipment issues. Leaks, misplumbed and miswired components from the factory, trades not crossing over well. still now DHW in the home as far as I know. The plumber assumed it was in the geo bid, no desuperheater was provided..

One was bid with wells and the driller hit caves 40 feet down so the plan changed to a huge pit in the yard. All that thin copper in the ground makes me nervous.

A 3rd DX in this area will not cool adequatly in the summer, something to do with the field loops. Same job where he can't get grass to grow over the DX field?

On one job I did the radiant to work within the geo temperatures. Another contractor did the 2 Unicos. A third did the DX install, and yet another the excavation.

Since I am the closest I get the no heat call first. Every call back has been geo related.

I think the conductivity of the soil is the biggest unknown. The better geo contractors around here are all upping their field size, or number of wells. Maybe global warming is to blame. Too much warm ground.

hot rod

Craig R Bergman

Hey Rich...

Call me at work. I still want to see the system you installed in your home!!!

Bergy

Mike Dilling

DX Geothermal

I waould like to respond to all the statements being made about DX geothermal. As so many of us know, proper and accurate training,design and installation are the key to any highly successful heating and cooling system. I have been designing, selling and training HVAC contractors to do DX geothermal systems since 1989. This past year, we sold to a wide array of dealers in Indiana, Michigan, Ohio and Illinois over 300 DX systems. Since 1989, the number has come to over 2000. Many of those sold in the early 1990's are still running just fine, but showing the effects of age. The exciting thing is that should those systems wear out and need replacing, we have current equipment designs that will utilize the exisiting copper fields and put the owners back in operations with even greater savings in cost of operation.
Over the years, I have dealt with all the issues you gentlemen have brought up. What this all really comes down to is proper understanding and then proper design, installation and training of the systems. If this is not done, the ground heaving, cracking, drying out, all the horrendous results and nightmares WILL COME TO PASS!
I have found 2 major issues that are most critical to address. Proper sizing is the key. The quantity of earth you impact with your copper field only holds so much energy and will release and absorb only so many btu's with a given temperature difference. To keep the ground from doing "nasty" things, we need to keep the temperature difference within a reasonable range. Most of the time, an undersized field will try to meet the load placed upon it by the house and an undersized system. This will cause the ground to freeze in the heating mode and the freezing causes the surface to heave or move if you will. This movement has great strength and can move decks, sidewalks, basement walls, all kinds of things. The key is an accurate load calculation and proper sizing of the system to meet those loads. If you do that, the owner will never know by looking that there is a copper field under the surface. When doing vertical loops, the grouting of the bore is critical. Using straight bentonite is like putting insulation on the tube when placing it in the hole. It does not conduct heat and basically prevents the earth from releasing or storing heat from the tube. Thermally enhanced grouts with high conductivity will ensure a very successful installation.
The second issue is that DX geothermal systems must be considered as a REFRIGERATION system versus an air conditioning/air source heat pump system. As a result, the operating pressures and temperatures will be significantly different than what a technician will expect to see on a conventional air source or water source product. Taking readings and interpreting them from a refrigeration stand point rather than an air conditioning standpoint is critial. The application of these systems to a high velocity duct system can be successful if the installer and designer understand that certain "modifications" to an "out of the box" High velocity air handler may be required to make it work.
Forums like this one are wonderful opportunities for an exchange of ideas and opportunities to learn. I hope we use this one to gain from each other's experience. Instead of trashing manufacturers and systems, perhaps we can offer up our difficulties for comment and advice and get issues resolved. I think it is worthwhile to remember that no manufacturer purposefully produces and sells equipment that will fail. Those of us in the field just need to be sure we know what the equipment can and can't do, how to properly apply it and be sure we follow the best installation procedures we can. As newer, higher efficiency equipment is developed, refined and marketed, the same old ways of installing and applying it just don't work any more. We all have to be willing to learn and re-learn and keep an open mind.

Mike Dilling

Geothermal Training

Please visit the website www.ecrtech.com and check on the dealer training schedules. There are several for you to choose from.

Mike Dilling

Reduce the load

Geoff, you are absolutely right! The whole thing starts with having the most energy efficient building possible. Then heating and cooling it with a geothermal system will make it the least operating cost possible.

Mike Dilling

Starting a geo division

Where are you located? Perhaps I can be of assistance.

scottie_3

DX running

Here is a good site with data logger and DX running real time
www.adaptiveinternetmonitoring.com/southshore/SouthShore.html

Brian Scram

DX geothermal

I have installed three DX systems,Forced air, 2 pit type, 1 diagonal bore here in northern Michigan and can report no performance issues in fact the first one is now 14 months old and it has heated and cooled and provided some hot water for a 1800 sq ft ranch on a full walkout basement for $385.00 for 1 year. I know this as fact because the heating electric usage is metered seperatley by the electric company at a leser rate .063 cents per KWH. The installation is easy enough and for closed loop applications I have no reservations reccomending DX. Brian

Burning Bush

recomended reading

First off i have to say i love you guys and thanks for the much needed info and open dialogue here on heating help. In
my neck of the woods it's hard too find someone to learn from. Second i was wondering if anyone could point me towards some good reading on ground source heat pumps. No time in the near future for classes unfortunately.

tom_49

Mike,

I am in SE Mass. near Foxboro.

Where are you?

Blackoakbob

oops!...

I should probably continue with my train of thought, as I didn't intend to toot my one horn, I just wanted to say that equipment is so much better now and applications are unlimited, but if you plan on jumping into geo you should attend some training and look at installations to get an idea if it's for you. You should also investigate loop and well contractors before you get into bed with them. See their installs and talk to the installers. I attended some training last year at this time and found the class very informative but the time I spent talking with the other contractors was invaluable. Most were very helpfull with do's and don'ts. Experience is great, but I prefer not to learn the hard way with most things. Best regards,

Craig R Bergman

Right!!!

I could not agree more! We attended the three day training class offered by IGSHPA and found about half of it concerned DIRT. We are HVAC guys, what do we know about DIRT?? Finding a loop contractor was a must for our company. Every spare moment was spent talking to those with experiance. As we did, one Looper was named over and over. That looper has done 95% of our installs and we have only had one problem with a loop field(a bad header) which they took care of right away.

If you want to get into Geo...Come on in, the water's fine!! Just make sure you can swim FIRST!! A mistake in this trade will be very expensive.

Bergy

[Deleted User]

Allow me to quibble for a moment...

B.O.B. said " I just wanted to say that equipment is so much better now and applications are unlimited"

Jeez, if their equipment is really that much better than it used to be, it must have REALLY been bad prior to this time.

Personally, my partner and I have a significant amount of experiene with an allegedly "state of the art" manufacturer, and our experience has been dismal at best. In fact, it has been so dismal that we have made a decision to NOT perform any more GSHP hydronic heating systems until which time the industry can prove to us that their equipment is really reliable, and as well designed as the modcon boilers we currently use.

Maybe we are asking too much of the equipment, but I was under the impression that these things could run forever, putting out water temperatures of 115 to 120 degrees F all day long and not miss a stroke. Afterall, they do show temperatures as high as 140 degrees F in their performance manuals.

Out of the dozen or so units we have installed, over 50% have experienced compressor failures. In fact, one of them has lost 3 compressors in 2 years. And before people start pointing the fingers of blame at the loop field, they are ALL engineered, and if anything, slightly over sized.

We are told by the rep that we are "working them too hard".

Really? If your equipment can't handle high (120 degree F) temperatures of discharge, then why doesn't the manufacturer put a non adjustable high limit OPERATING control within their safety string to limit the temperature of operation to YOUR desired maximum? The unit has NEVER gone off on the manual reset high limit provided by the factory.

It is doing DHW pre heat via an indirect and space heat via RFH system and AC in the summer, but is that really working it too hard? We were not told of any limitations when we took the dealership on. To their credit, the factory has paid for the comopnents of replacement at each failure, but this is down right emberrasing, and unfortunately, the triple loss owner is an attorney. I guess what really bothers me is that the factory can't or hasn't told us the reasons for failure, other than "compressor failure".

And the assemblage of these units is attrocious. WHy would you put a critical component in a position that renders it almost virtually useless when it comes time for replacement? (Load circulator) Ship the pump loose and let me put it some place where it is accessible. Don't cram it in the bottom of the unit where I can't even get wrenches on it to replace it.

In my estimation, this manufacturer is like a group of farmers that got hooked up with a bunch of back yard inventors who understood refrigeration and had a wedding. None of them has the foggiest idea about the field of service, repair and or operation. Their installation manuals are rediculous at best.

Until THIS industry gets caught up technology wise with the mod con industry, I think we will limit our exposure and liability by not using them for producing heat. Oh sure, they work fantastic for doing cooling, but as for doing a good job of doing heating, they leave a LOT to be desired. Sure am glad I didn't spec them for the DHW preheat system for the industrial application I was looking at. I'b probably be back ther monthly replacing compressors.

Sorry for the bitter apples, but we can't afford to keep doing business this way.

And no, I won't mention the manufacturer directly by name. I think they ALL suffer from the same disease, that being the GREEN SCENE disease...

ME

troy_8

Ditto

Wow I thought it was me. I have had the same experience. It seemed odd when the manufacturer didn't seem surprised that it was the 3rd compressor in 3 years. I've replaced every single part in this unit. When it works it is great. Thank god I installed an lp backup boiler.

Rich L.

Compressor failures ME

Mark I respect your not saying what type of units these were, but will you say what type of compressors they are? I don't do much residential work but still have done a half dozen of these over the past 10 yrs and have yet to have a compressor failure. I put a w-w system in my own house 1-1/2 years ago and it's purring along like a kitten. Low utilities and no problems (so far!). I can't complain about these systems at all. Well ok, the one I like does leave a bit to be desired with the installation manual. It may be written by the same group that wrote yours! So far though that's my only complaint.

I have spoke to installers that have been doing this for over 30 years and they've been very satisfied and pleased with these systems.

Hi limit: I think that's a very valid point. If you can work it too hard than it should have an internal high limit built right in.

Just my rambling thoughts. I'm enjoying reading everybodys inputs and experiences.

Best regards, Rich L

hot_rod

Here here, Mark

Excellent post and a very common determination.

If anyone is looking for some slightly user, never worked, new compressor, 3 moth old DX equipment, gimme a call.

I know of 3 systems that ALL came mis-plumbed, mis-wired, and for whatever reason are unable to heat air or water.

they looked like they were assembled by kindergarteners, the dealers and reps, and now installers are throwing their hands in the air, the owner is into them close to 100 grand.

Give me a break, if this is the technology that is going to save the planet, and lessen our energy dependence..

hot rod

[Deleted User]

Both...

Recips AND scrolls, both made by Copeland. I guess when you're building billions of compressors, a 2% failure rate is expected. They just must blow it off...

ME

Blackoakbob

in the early....

years, yes, there were many, many compressor failures, along with poor defrost timers and other electrical components that couldn't handle the climate, i.e. Minnesota. We have always needed additional heat with the heat pumps and with the advent of duel fuel systems, a back up heating system like heat pump with electric strip heat on top of a gas or oil furnace. I think everyone should have two ways to heat their house, if not the economics of a choice of fuels by cost, then the dependablity of mechanical equipment. Which brings me to the point of my post.
I think we as contractors have all been victims of the "Music Man" type salesman and manufacturer. We may not have sold an Edsel but there have been many, many peices of equipment like it in this industry, from Japanese wall hung waterheaters sold for boilers, pulse combustion, condensing furnaces with steel primary heatexchangers, and my personal nemesis,opus boilers. These are my personal opinions.
Just rememeber when the salesman cashes his check and the manufacturer turns out the lights on Friday night and goes home....it's just you, you're experience and training that's left when that call comes in. Only believe half of what the mfg and sales people tell you, learn as much as you can and sell only what you're comfortable installing and repairing, risk tolerance. I always like to save some piece of the equipment that has caused me grief to remind me to make careful choices. I still get bite in the a$$ and it's humbling to say the least. My two cents, best regards, all.

Henry_6

Geothermal SYSTEMS

I have read carefully the dialog about geothermal heat pumps and can actually say that the forced air and hydronic systems which we designed and installed were mostly running as designed and sized(Manual J) without multiple compressors for over 20 years. Some of these machines are running on their original recip compressors for 75,000 hours and more. They will perform hydronic heating from 80-120f all day long as long as a buffer tank is used, scroll compressors are avoided, and an outdoor reset control is properly calibrated. We are in the Northeast (Greater Boston) and have many systems installed with radiant floor heating and/or ducted cooling. What's the difference? LATENT heat. The ground collector is sized for 80-100 ft per ton, with an oversized evaporator/condenser operating as the heat source/sink. We do not do DX because of the consideration of 1) static electricity corrosion with moving liquid refrigerant 2) the conversion to R-410a at operating pressures of 300-500 psig and 3) the cost of refilling a system which has leaked. Our systems use high density PE with butt fusion welds and a U bend at the bottom of a 400-700 ft hard rock well. We can make DHW on demand and recycle heat during the summer for hot water and swimming pool heating.This is the type of system that is used in Europe and operates with a COP of 3.0-4.20 seasonally, or in English, $1.00 of electric energy equals $3.00-$4.20 of heating, cooling or DHW. With oil at $9.00 per barrel 12-13 years ago, these companies could not sell against the operating costs of 80-90 cent oil and went back to Europe to make real money.

I know that I sound like I'm on a soapbox, but these systems really do what they say. If you are only getting 1 BTU for each pound of water you are passing through the evaporator, it takes a tremendous earth loop to supply enough source energy for the system to work. I would rather put my money in the box in the basement than the yard and have control over my output to increase the energy supplied.Have you ever tried to pull an artesian well pump when the temperature is 10-20F? I don't care what the ground soil temperature is during the winter, because my propylene glycol and water mixture is entering at 32F and leaving at 27F from November 1-May 1.

Now if we as American energy users could realize that we can recycle energy from treated waste water, harvest latent heat from the ground, use the ground instead of cooling towers, and generally rewrite the conventional engineering theory that a positive cash flow from discharge heat is possible then we will not need oil imports from hostile countries. Imagine that!!!!

Henry_6

Geothermal SYSTEMS

I have read carefully the dialog about geothermal heat pumps and can actually say that the forced air and hydronic systems which we designed and installed were mostly running as designed and sized(Manual J) without multiple compressors for over 20 years. Some of these machines are running on their original recip compressors for 75,000 hours and more. They will perform hydronic heating from 80-120f all day long as long as a buffer tank is used, scroll compressors are avoided, and an outdoor reset control is properly calibrated. We are in the Northeast (Greater Boston) and have many systems installed with radiant floor heating and/or ducted cooling. What's the difference? LATENT heat. The ground collector is sized for 80-100 ft per ton, with an oversized evaporator/condenser operating as the heat source/sink. We do not do DX because of the consideration of 1) static electricity corrosion with moving liquid refrigerant 2) the conversion to R-410a at operating pressures of 300-500 psig and 3) the cost of refilling a system which has leaked. Our systems use high density PE with butt fusion welds and a U bend at the bottom of a 400-700 ft hard rock well. We can make DHW on demand and recycle heat during the summer for hot water and swimming pool heating.This is the type of system that is used in Europe and operates with a COP of 3.0-4.20 seasonally, or in English, $1.00 of electric energy equals $3.00-$4.20 of heating, cooling or DHW. With oil at $9.00 per barrel 12-13 years ago, these companies could not sell against the operating costs of 80-90 cent oil and went back to Europe to make real money.

I know that I sound like I'm on a soapbox, but these systems really do what they say. If you are only getting 1 BTU for each pound of water you are passing through the evaporator, it takes a tremendous earth loop to supply enough source energy for the system to work. I would rather put my money in the box in the basement than the yard and have control over my output to increase the energy supplied.Have you ever tried to pull an artesian well pump when the temperature is 10-20F? I don't care what the ground soil temperature is during the winter, because my propylene glycol and water mixture is entering at 32F and leaving at 27F from November 1-May 1.

Now if we as American energy users could realize that we can recycle energy from treated waste water, harvest latent heat from the ground, use the ground instead of cooling towers, and generally rewrite the conventional engineering theory that a positive cash flow from discharge heat is possible then we will not need oil imports from hostile countries. Imagine that!!!!

Sorry for the duplicate.

[Deleted User]

Henry...

I have no doubt in anything you've said. I strongly believe in the technology, and as soon as Viessmann hits the market with their well thought out, test and corrected GSHP, I will consider it. Of course, they WILL have to throw a reversing valve into it if they want to sell it in America. The Euro's don't chill like we do...

And like they say, maybe I'm expecting too much out of these systems. I don't do an outdoor reset because I can show that preheating the DHW as high as possible using the GSHP is cheaper than the local alternative. Hence, they are being run at their maximum potential all the time. Can they not do that?

I have used WSHP to do all kinds of things, and will continue to use the technology, but I'm thinking it would be a LOT less money to go air source (the technology has changed SIGNIFICANTLY), maybe use the attic as a heat source during the winter, convert and store that in DHW preheat/buffer tanks (reverse indirects), and tie that to a high efficiency (WarmBoard or equal system) and let 'er rip.

The Daikin Altherma is looking pretty darned good....

Doing well in Europe...

I guess on these systems that are eating compressors, I will have to throw an outdoor reset on them and forget about DHW preheat to any major degree. It is what it is, and you get what you got.

And welcome to the Wall Henry. Thanks for contributing...

ME

BC_3

Have your cake and eat it, too

Mark, I seperate the DHW and radiant temps by using a 3-way zone valve and plate heat exchanger for the DHW. My radiant runs at 80-100F most of the year while the DHW preheat tank can run near the limit at a much lower duty cycle. This also saves a ton of money - the COP of my unit at 100F is 50% higher than at 115F. The added zone valve and tank will pay for themselves in less than a year in my case (in theory at least - the DHW isn't hooked up yet!).

Not sure how this will affect compressor durability. I agree that if it is operating within spec it should be able to run 24/7 without a problem. If it isn't capable of doing this the specs need to be changed.

Henry_6

Geothermal Part 2

Hi Mark:
I enjoyed meeting you several years ago at Dan's first Wetstock. I have always admired your analytical and mechanical skills. I have the solution to your compressor problem related to DHW. The trick is to have a DHW condenser immediately leaving the discharge of the compressor, but before the reversing valve. This condenser is the same size as the reversible condenser/evaporators which are used for ground loop on one side and distribution(hydronic or hydro/air) on the other side. The evaporator is always directed through an accumulator and the condenser is always directed through a receiver. The last step is a pair of TXV's sized for the system. Now you have a system, instead of an empty box. The best heat exchangers for this application are brazed plate stainless/copper and bingo, you get a system which can evaporate a 500' ground loop with a 1/2hp circulator, a DHW desuperheater which can be an on demand full capacity condenser by turning on a circulator to a double shell tank, but when the compressor run time is >15 minutes per hour, the DHW pump doesn't come on for demand because 3-4% is desuperheated to the outer shell of the DHW tank and a full capacity boiler/chiller able to serve multiple air handlers without having to find a phase converter or single phase chiller (almost impossible to find).
I really hope that my friend Rich Trethewey makes the case for Viessmann to sell their systems here in the states, but the 50 cycle, 3phase 380 volt systems are very difficult to adapt. I'd love to have a chat with you at some point, because I am looking for a way to make these systems here in the US. I have had a great ride designing and marketing latent heat systems and finally conventional fueled systems are making this concept competitive.
Don't give up, sometimes it is what it is, but usually that is the New England Patriots. Thanks

vinny50

dx geothermal

where are there training classes?   also who are the main manufacturers in this business---earthlinked etc..,.   who has the best track record. Do you need backup heat for these systems?? Is it  too soon for commercial appplication?? If  so who is the best fit??