Just to reiterate, I do not seek compensation. I just want to help stop the bleeding. You have excellent equipment, but unfortunately an un-evolved design.
PM me and I can shoot over a design to start the dialog.

Thanks, check your inbox.
Mike

Bearing in mind that I have no direct experience with this system type:

1) I 2nd Doc's remarks asserting the insanity of heating load side water any hotter than needed in the radiant floor

2) Given Alaska's huge temperature swings it would be professional malpractice to omit outdoor reset from load side temperature control

3) Decreasing load side temperature not only increases efficiency but also increases capacity

4)Geo systems have long been able to operate on source side water temps as low as 20*F, assuming proper antifreeze. The standard low temp cut-out for freeze protected systems is 15*F, so loop temps in the 20s are acceptable, albeit at some reduction in both capacity and efficiency compared with milder conditions.

5) Geo systems able to produce 140*F load water are relatively new on the scene. I wonder if the combination of low source and high load temperatures results in damaging conditions / premature failure of the compressor. Looking at a 410a PT chart: Source temperatures in the 20s imply evaporating pressures in the 80s. Load temperatures approaching 140 imply condensing pressures approaching 600.

Taken together, the result is a compression ratio in the range of 6-8. That may result in borderline low refrigerant mass flow and density at the suction inlet. That combined with very high discharge pressure and temperature would seem to risk overheating compressor windings and / or lubricating oil.

6) I think it would be hard for most of us contractors to charge labor for a compressor replacement so early in a system's life cycle if we were the installing contractor.

7) I'm in envy of a contractor able to install geo summers in Alaska but then winter in Florida...I can envision service and support issues when temps plummet.

Don't give up!

Thanks Curt, I know I have no outdoor sensor input if that is what you are referring to in (2). When the dealer that installed the system was handing it off to me, I videoed the "presentation' so I could remember all the details. On (6) the warranty work is done by another company that had no involvement in the install. They are as frustrated as I am and have determined after consulting WF, it is not having enough source tubing. They have said I need another 6000 feet of tubing.The dealer/installer claims (via text) that WF said 6000 feet was enough for both 4 ton units. Since I only can power the unit off peak, 11 hours a day (9p-5a and 1p-4p) I think the designer was trying to put as much heat as possible in my 120 gallon storage tank for the "on peak" power times.As someone pointed out here that amount of BTUs would only provide 1 hour worth of heat. He actually had the unit set to 145* and lowered the temp to 140* before he left. That 140* aquastat is at the bottom of the storage tank. I took some temp readings last night and output temp was 6.5* higher than the Hydrozone readout (138) on the WF unit. Return temp was 4* colder than the output.
Your thoughts on 410A are interesting, all my experience is with R-22, R-404A and R-502 on fishing boats that chill water for quality purposes, but I am very familiar with refrigerant pressures/temperatures. I am not a fan of running anything at or near its limits.
Thanks for your thoughts. Mike
BTW I am preheating the water with a Toyo om128 to 115* which then goes to standby when the GSHP hits 120*. By itself one unit (the other unit is awaiting another compressor) can only generate 92* max. When both units were running they hit 140* on the Hydrozone controller.

Willowbilly, you have a PM, if you could send me your email.

You loop data suggest that your loop is doing fine, especially for Alaska ambient temperatures. WF does not make statement about loop sizing, they are smarter than that. They sell boxes, not loop designs. So there is a bit of a BS flag rising here in regards to your installer as well as you current company. What might be concerning is the 2x2 circulation pumps on the same loop field. Do you recall what the pipe size is going out to the loop field.
Running the tank up to 140 degrees F instead of 100 degrees F for storage reasons does not make sense. Lets say you have 120 gallons in your tank and 80 gallons in the rest of the system, 200 total.
40F delta T x 8.33 x 200 gal = 66,640 BTUs
It gets you a couple hours on a cold day but it renders the system inefficient for life. The difference in efficiency between 140F and 100F is 60% less at 140F compared to 100F. You loose about 15% for every 10F hotter water. Not to mention the stress on the compressor.

Who was the designer? Someone else than the installation company?

Something else is odd when the one unit can only hit 92F. Do you always preheat the water, or only now dues to one heatpump not operational.

Having a heating system offline 13 hours per day is certainly a challenging idea in such a cold climate. I suppose it gives the loop field some time to recover, but I'm not sure how that relates / works with the phase change DJ mentioned...water in ground around loops freezes. I doubt it would thaw much during the daily on-peak outages.

As has been mentioned, a couple hundred gallons of water can store only a couple hours worth of heat relative to the home's load. In addition to the several issues DJ has mentioned, designing for off-peak power only would include three fundamental considerations:

1) Computing the DAILY heat loss during a design (99%) day, and

2) Sizing the geo to be able to furnish perhaps 75-90% of the design day load during 11 hours of run time (the percentage of design day load to be met by a geo system is a function of cost of backup heat, incremental cost per ton, and client preference), and,

3) Economically storing heat energy to cover load during the on-peak outage intervals. Off the top of my head, assuming access and space are available, and if the load side water system could be operated non-pressurized, one or more plastic agricultural water tanks might fit the bill. 1000 Gallons stores 166 kBtu via a delta of 20*F

You mentioned heat loss of 31,500 Btuh at 0*F outside. Given low outdoor temperatures you reported earlier, chances are your area's design winter temperature is a fair bit lower than that. If you'll share your city we can narrow that down. Alaska has huge variation depending on location.


If off-peak power is truly cheap, consider electric resistance as a backup / peak source. You already have the gas boiler. In such a severe climate I'd want multiple sources. Calculate cost per delivered Btu in evaluating backups.

A look at the specification catalog for your WaterFurnace models shows no data for entering source temperature below 30*F, and that operating at 25 - 30*F is labeled "sensitive operating zone"

I continue to find it odd that the installer winters in Florida and saddles you with labor costs for compressor replacement so early in the systems' lives especially given such glaring design flaws and omissions.

Usually the phase change stabilizes the loop field. In Alaska one would suspect that the ground around the pipes goes through the phase change much more. I don't see much recovery of the ground loop since you are close to 32F in undisturbed ground anyway. Attached is a piping strategy you need to get to, with an outdoor reset running your floor supply temp at 90-95 degrees. I would suggest you abondon your off peak heating strategy, since your system will run so much more efficient if you lower the temps, besides lowering the stress on the compressor. To create thermal storage with a geo system in Alaska ground conditions and climate is a bad idea. I assume it was a typo from Curt when he mentioned to consider electric resistance as a peak source. Attached is a suggested load piping to fix your current issues, we can implement a piping to take care of your hot water as well. Your loop piping and pumping deserves a look as well.

I'll defer to DJ's experience with heating-dominated climates. Since off-peak power costs only half of on-peak power it is certainly tempting to configure a system with off-peak power in mind, but as now configured / operated it is counter productive as to efficiency and threatens durability.

My use of "peak" above was not a typo but instead an unfortunate ambiguity. I was suggesting calculating cost of resistance heat as a source of additional heat during very cold weather (peak heating load) not on-peak electricity. To further evaluate alternatives would requiring knowing cost per kWh as well as cost of gas / propane.

I live in Willow AK 99688.Typically we are 20* colder than Anchorage due to the distance from the ocean. Unfortunately natural gas is 30 miles south of me and unlikely to be supplied in the next 30 years due to no infrastructure to supply. The toyo boiler uses #1 fuel oil at 1 gallon per hour, the latest delivery was $2.33/gallon. Electricity cost is $.0958/Kwh (off peak). Full electrical rate is $.169/kWh. What caused the interest for geoheat was when fuel prices approached $5/gal. I am only allowed to use offpeak for the WF units and their field pumps and I have a separate service with a timer for that system. I am only using the toyo boiler to preheat the water now because one unit will not heat the house. I installed the boiler after the second compressor failed.What I am using now is a hybrid system that uses the geofield when THAT system has power. I have 20% methanol in the field to prevent freeze up. The ground lines coming into the house are 1 14" id.Field tubing 3/4 HDP plumbed in to 10 head manifold, 1 manifold supply and 1 for return. Thanks Doc I got the attachment. Need to go to work now, I'll get back when i Can Thanks again Mike

My "broken" system used 2254 kWh last month.
Mike

Any idea how long the 1.25" header pipe is? In the house, and outside the house. One way to the loop field.

1.25" pipe supporting 8 tons total might be a bit sketchy.

You might want to put one units and the off peak meter and the other one on the regular meter.

Any idea how long the 1.25" header pipe is? In the house, and outside the house. One way to the loop field.

1.25" pipe supporting 8 tons total might be a bit sketchy.

You might want to put one units and the off peak meter and the other one on the regular meter.

Company that did the design and oversaw design and installation of my system. http://www.alaskageothermal.net/ Chuck Renfro designed and oversaw installation of the entire system. Fought with the plumber a lot and is placing some of the blame on him. Plumber does great work and was paid to do whatever was asked/required. All the copper in the pictures is his work. Chuck did the WF installation and the ground side of the system. He oversaw the copper work as all that is his idea.
Wolfe Refrigeration is doing the warranty work as Chuck is unavailable. http://wolfealaska.com/ They are a WF authorized warranty company. Wolfe has been very responsive to my plight. They have been in contact with WF to get the original compressor replaced as well as getting WF to send a second compressor. They will be doing the install when it arrives. Wolfe is also the one bringing the WF rep to my home as well as a few other troubled systems (hopefully) next month.
It makes a lot of sense to me to take the hit and run the system as needed and give up on off peak. After the water furnace representative visits I will have a clearer picture from their side. The general contractor (a personal friend) is feeling really bad about this situation because he "drank the koolaid" and convinced me to invest in the technology. He also has an older ailing system with a locked compressor that is still under warranty. My main problem is that while there are refrigeration experts and plumbers that can put things together, I have yet to find a company in Alaska that has all the tools (local knowledge, design experience in subarctic conditions and the engineering wherewith-al)l.
My view so far is this. I run a commercial boat for a living. You can make a boat go fast with big horsepower or hull efficiency. I think Chuck's approach is the big horsepower version using max heat. Personally I prefer an efficient hull and save the fuel.
Mike

I would guess that each side of the 1 1/4 pipe is 100 feet. There is also are two 90's in the system (both supply and return) which will increase the friction loss.

Your pressure drop is around 57 ft/hd, 26 ft/hd is coming from the 110 ft (10ft for the elbows) of 1.25" of header pipe each way. Not good for a new system, you are wasting quite a bit of pumping power. Your 10 x 600' loop itself is good, the problem is the 1.25" pipe going out there to the loop field. 1.5" cuts the pressure drop in half, 2" pipe cuts it down by 80%.

Be aware that WF sells heat pumps to installers. They are not involved in system designs, nor will the rep have much knowledge. Your system appears clean, but the devil is in the details.

The analogy with the boat accounts for the pipe. Right now the additional problem is that the boat is not much moving at all, it its way overloaded, and in addition its gets structurally damaged from running aground all the time. Just a thought here: While I understand your frustration, you should be discrete of naming the parties involved. You don't want people to become defensive, you want them motivated to make things right.

It seems that gathering empirical data from your system may help determine the cause for the multiple compressor failures.

On the geo side, what is the actual GPM flow of coolant?
What are the entering and returning temperatures from the geo loop to the GSHP?
On the buffer tank (house) side, what is the actual water flow GPM rate and what are the entering and leaving temps?
What is your total energy consumption for all equipment required to make heat to the isolated buffer tank which seems to be the only zone the GSHP(s) is directly heating.

And what is the circuit breaker size?

Ordering a flow meter today.
When the second compressor was installed the tech recorded the following information. Unit draw 24.6 amps (each unit on a 50 amp breaker). Line voltage 241 volts. Unit output 122* @ 22 psi, return 117.5 @ 25 psi NOTE power shut off prior to achieving the called for 140*. Geosource input temp 28.2* @37psi. Return to field temp 24* at 33 psi. High side refrigerant pressure 420 psi, low side 71 psi. Looking at my refrigerant chart, 410A is 115* at 418 psi. When unit running I will attempt to measure power on what I can (most wire in metal shielded cover) and pull specs from literature from what I can't.
Digging up my new deck, landscaping including terracing and wife's flower bed to replace the tubing to the manifold is not going to be fun.
Mike

When looking at ordering a flow meters I see a great difference in price and in pipe types (copper, abs, ect.) Any suggestions on which to get? I'll need to measure flow in copper and hdp pipe.
Thanks
Mike
Also to insult to injury, a lot of places don't ship to AK. I guess we are a foreign country.

Looking the flow chart two of my flow pumps can handle 5 gpm about 68 feet of head at 0 gpm. Looks like I'm pumping 5 gpm with one unit running. With both units running the flow goes to 22 gpm. The key is what diameter of pipes is this pump chart set for. I also ran fire trucks professionally for 10 years and know that hose diameter determines gpm at any psi. i guess more research on my part is needed. Mike

Well, was the delta PSI recorded when one or when both units were running?

Don't bother about a flowmeter, you have not a way to measure flow with a meter unless you cut into the lines, you don't want to do that. Plus you introduce a permanent flow restriction.

Give me a second, I'll run the flow numbers for you.