I'm really curious about this one.

If the data offered is accurate, and the GSHP system is working per manufacturer's specs, then Mr. Drao is extracting about 1.4 *million* BTUs from his 5600 sf residence and putting it into the earch - daily!  That's a big hole in the structure, noting that on average a day at the moment is zero Cooling Degree Days (Michigan climate)

If the data offered is accurate, and the GSHP system is not working per manufacturer's specs, then Mr. Drao is burning through 82 KWH of electricity - daily - for zero CDD days.  That's an incredible amount of eletrical energy being consuming by a malfunctioning GSHP system, for zero CDD days.

Either way, something's grossly wrong.  It hard for me to understand why it's difficult to troubleshoot this one (by someone on-site).

Best regards,

Bill

as an added bonus consumption does not include blowers.....

I am inviting Brian Garno from Garno Brothers Inc( he installed my units) to get involved in the discussion to clarify data so that we may arrive at a reasonable soultion to this issue. Thanks for all the help.

> It hard for me to understand why it's difficult to troubleshoot this one (by someone on-site).

I agree and IMO, thermal capacity and efficiency testing should be done before final payment is made. One has to wonder how many systems are not working to specs but aren't so bad that it is obvious.

he asks a second time......

Hello everyone. At the request of drao I will offer some input. As stated there are three units. All are on vertical V-1 loops. There is 100' of bore per ton. When originally installed there was some variations in the bore depth. The four and five ton loops are in straight line. This was done because of clearance issues with undergroung utilities. After spending some quality time with the engineer from ETI this was changed. The a coils on the existing furnaces were also upgraded. The four ton now has a five ton coil and the five ton has a 7 1/2 ton coil.
I don't have my notes with me so I can't give numbers right now. My feeling is given the suction and discharge pressures of the units the current draw is too high. I have also done blower door testing on the home and checked the insulation with a FLIR cam. Some problems were found and corrected. There is also duct leakage issues. Unfortunately the duct is buried in a finshed basement ceilling. I was hoping to find an Aeroseal contractor,
but have had no luck. I appreciate any input.
Brian

Hello Brian

 

Thanks for clearing up the depths, as a V1 100' pattern. And Welcome!

I'm sure Mike is your Dist. has he got involved.

Hello, it sounds like you're getting some excellent advice here. Based on my personal experience with an ECR Earthlinked DX system, I have one thing to check that could do what you're seeing, but it should have been picked up by the installer when they checked the system pressures, superheat, subcooling etc. Was the proper backfill of the loops verified? My system was installed in January when it was miserable out (not my idea). The installer backfilled but did not flush the fill down properly. So basically my loops were hanging in the air with a tiny fraction of the fill around them that they should have. I fixed this myself and the system works pretty well now. I discovered it because I installed temperature sensors on each ground loop so that I could monitor the ground temperature throughout the season. Unfortunately, I'm probably the only one anal enough to install their ground loops this way. If your installer did not properly backfill the loops, then the system would keep trying to reject heat into the ground but can't because the loops are not thermally connected to the ground. This should cause the high-pressure lockout to kick in, but it's possible that there's enough heat transfer to prevent this but still seriously compromise the system's performance. However, it should be easy to determine if this type of problem exists because the system parameters will be way off. If you want to check out your loops yourself, you can simply drag your hose over to the bore holes and squirt water down the hole along the loop. If the backfill isn't complete, the water will wash down the sand (which is what ECR uses to backfill in areas where it is permitted). You will end up flushing the sand down and allowing it to settle as the water is absorbed into the ground. You can then add more sand (tons of it), flushing with water, until no more will fill the bores. If your installer used a Bentonite grout, which is the proper procedure for plastic ground loops, or plugged the surface with an impervious fill (required by some codes to prevent groundwater contamination) then you obviously can't test things this way.

Duct loss seems unlikely to be this major a contributor. What were the man j loads for the units' zones.
J

Oh and what grout was used?
j

I will have to consult my installer Brian for the answer.

The grouting issue may then be a tough one to check. However, someone should still be able to get a read on the temperatures to and from the ground loops to see if they're in the right neighborhoods. They should also be able to check your supply and return temperatures, and knowing the air flow, compute the BTU delivery of the systems. It won't be exact, but it will be good enough to ensure that things are close to spec. That should have been one of the first things done. I simply cannot imagine that the problem won't pop out when you check these things. In your climate, the air conditioning requirements should be absolutely minimal, even with a big house, unless you've got some insane amount of heat being generated inside the house. If I were diagnosing this, I would do a few things, in this order(ignoring the refrigerant level checks and basic startup of the system): 1) check supply/return temperatures. Compute BTUs based on air flow and temperature drop. For example, air flow = 1600 CFM. temp drop = 20F. BTUs is *roughly* 1.08 * 1600 * 20 = 34560. 2) Measure the running amperage draw for the compressors. you should read about 1kw load per ton. That's about 4.17 amps per ton on a 240v circuit. If these two things are in the right ballpark for all the units, then the problem is in your house, not in your systems. But I cannot for the life of me imagine that these were not among the first things checked. As for Aeroseal, one of my clients used this and even though the job was incomplete, it substantially reduced duct losses. Just make sure they really seal up all the registers. My client ended up with sticky goop all over his belongings in the basement where the ducts were exposed.

The original loops were grouted with a thermally enhanced grout per ETI instructions. When I redid the loops on the four and five ton systems we used Supergrout. The hole drao refers to is in the trench with the manifolds it is not near the bore holes. When I get a chance I will post the system pressures and temperatures. The memo about the wrong size caps came out from testing on another system I have that is also using too much electricity. Thanks for your input.
Brian

Sounds like a strong argument for an aeroseal pro.
The installer now contributing here will be able to tell us the grout used and the heat load.
I know of no one in MI with more of these installs. Not a suck up just a fact. We are way past the obvious problems.
J

I wonder if anyone knows of a local aeroseal contractor in Michigan?  I would like to check into that.  Also yesterday's reads are:

                                   2 Ton                    4 Ton                        5 Ton                     Main

08/24/09

00064        02

1814            09

4784           07

02434           74            High 76F

 

It is so obvious that everytime my units come on they guzzle electicity -a far cry from being GREEN!

Brian, it's great to have you hear. It's rare to have the installer contributing on these types of forums.

The fact is, there are a very limited number of options that could be causing the problems, so it should be possible to methodically rule them out.
- excessive compressor draw
- excessive air handler draw
- defective compressor
- leaky ductwork
- inadequate thermal transfer between ground loops and ground
- excessive home heat loss/gain
- improper refrigerant charge
- power meter errors
- user issues

Have I missed anything?

Joe - you note that we're past the obvious problems. The point I'm making is that it is impossible for it to be anything other than these issues. If you definitively rule out each of these, you will be led to the only possible answer(s).

Ok, so let us assume that Brian has definitively ruled out some items:
Excessive compressor/air handler draw
Improper refrigerant charge
Power meter errors
Excessive home heat loss/gain
User issues (i.e. 80F heat during winter, 60F cooling during summer)

We are left with only three possible problems
- compressor malfunction
- leaky ductwork
- inadequate thermal transfer between ground loops and ground
- user issues (there is ALWAYS an opportunity for user consumption patterns to screw with the numbers, regardless of what they tell us).

It is possible that the compressor partly works. Let's say that it has an internal leak and so it's not compressing/moving enough refrigerant. That would cause potentially continuous runtime/extremely high consumption. But, this should have been caught by during testing.

Question 1: are you 100% sure that the compressor is functioning properly?

I've seen leaky ductwork that would cause very significant issues - i.e. a return duct detached in the attic. A single problem of this sort could easily double the load on the system. If you combined this with setting the thermostat to run the fan continuously, rather than in the "auto" setting, then during the summer, you could be sucking in several hundred CFM of 130F air which would be a huge heat/moisture gain for the house.
However, this would have been immediately obvious during the blower door test as they would have felt all that hot air sucked into the house via the returns.

So, question 2 is: were the ducts adequately evaluated for leakage? Are you 100% sure that you're not sucking hot air in the return ducts? Are you 100% sure that the thermostat is being used properly in the "auto" setting?

Once the ductwork and compressors are ruled out, the only possible remaining problem is the ground loop conduction. Even if the loops were installed as per proper protocols, it is possible that the bore-hole fill was not correct.

So, question 3 is: does each loop show the expected temperature change between the refrigerant going into the ground and the refrigerant coming from the ground? This is non-trivial as multiple factors could be affecting this measurement. For example, if the system were under charged with refrigerant, then even a slightly conducting ground loop could reject the heat into the ground and come back colder. Or, if the compressor was moving the refrigerant through slowly, then again, the heat could be rejected to the ground. But again, if all the standard refrigerant tests were done properly and came up clean, this test should be valid.

That's it, unless I missed a factor. There are only a few potential problems. Rule them out 100% and move on to the next and you will discover the real issue.

One final note - the data shown above indicate an inconsistent relationship between the consumption of the systems. The ratio of draws should be relatively consistent. What we see initially is the 4 and 5-ton units drawing about the same. Then, after a couple of days, the 4-ton remains high, about 8-10 hours per day of run time while the 5-ton system drops to 2-3 hours/day of runtime. i am also seeing a disconnect between the system consumptions and the total consumption. For example, on the 20th, all the systems consumed 50 kwh, and the house used a total of 107, so the normal house draws, and I guess the air handlers, used 57 kwh. If the house is using 50kwh/day, that's $150/month of basline usage. Likewise on the 15th, the systems used 154kwh and the house used 278kwh, so there was 124kwh of non compressor usage. This points STRONGLY to excessive household consumption IN ADDITION to high system consumption.

I sense a pool pump or a fountain or some other large pumps running in this household. There is no way that a typical houshold should use 124 kwh after air conditioning. But again, we clearly have multiple issues. The household uses way too many kwh, and the systems are running too much.

I disagree, yesterdays numbers look normal. About an hour runtime for the 2-ton and 2kwh consumption, 2 hours and 9kwh for the 4-ton and an hour and a half or 7kwh for the 5-ton, total consumption of 18kwh, while the rest of your household guzzled 56kwh of electricity.