Engineer and Geotek: It's back to the books for me... It has been running better since moving the capillary tube off of the discharge line. But still under performing. The HVAC guy did not call back today.. Will have him get here as soon as he can.

Thanks guys, I appreciate your guidance!

John

Well I'm happy to report good news. The HVAC guy came, hooked up his gauges, added refrigerant, waived his hand in a clockwise motion above the unit and mumbled something scary, I guess in HVAC tounge. The pressures were low but now read as recommended by WaterFurnace.

We now have a 23 degree delta t on air. However... On a call for stage two, the amp draw on the compressor remains unchanged at 5.6 a. So it appears there "were" two problems, but now there is only only ONE! The Comfort Alert module has failed. This also explains why the unit gave no error codes ever. Will replace it.

We expect a nice drop in the Electric bill. TAKE THAT ALABAMA POWER!

Thanks all!

John (and my wife - she is happy too)

John,

Is the leak fixed now?

Regards,

Masoud

I would expect compressor amps to increase by 50% or thereabouts on a stage two call. There will be little or no difference in sound other than a bit more blower noise.

That air delta T is within range of what I'd expect. I would have expected the addition of refrigerant to raise compressor amps. Did he say how much he added?

Also, what water side delta T are you now seeing?

Masoud: We do not believe there is a leak. When the unit was installed there were no checks performed on the refrigerant side. Was told that the unit comes from the manufacturer pre-charged and ready to go. Only the water loop was checked for pressure when it was installed. We recorded the pressures and temps after tonight's activity. If performance issues come up again, the HVAC guy will come back and search for leaks. We were happy with the low electric bills even though they have always been higher then predicted on the HERS report. I'm eager to see the energy savings going forward.

Engineer: OOOPS. I did not measure water side temps, but will go do that and report back. Nor did not ask how much refrigerant was added. It did not look like much, although I am not much qualified to know how much much is. I'm absolutely certain however, that the Comfort Alert module has done nothing more then display the pretty green light, tricking me into believing everything is just fine....

Not only has this exercise been an enjoyable learning experience, it has shown (to me anyway) just how valuable a monitoring system can be.

You guys have been great coaches and teachers. I cannot thank you enough!

John

Is your system a package (blower, heat exchangers and compressor all in a single cabinet) or a split? (two cabinets connected by refrigerant lines, one with compressor and heat exchangers, other with blower and ductwork).

If refrigerant needed to be added, there is almost certainly a leak somewhere.

John, look back at the chart I posted in this thread a couple of days ago, showing highest compressor discharge temp each day.  My first indication that I had a leak with my 3 ton unit was from this chart. 

At about Week -54, my 3 ton's compressor discharge temp started slowly rising, while my 5 ton unit stayed constant.  Since the water supply is a single loop serving both units, I knew the 3 ton had developed a problem, just didn't know what.

As the leak continued, compressor discharge temp kept rising.  I'm not a refrigeration expert by any means (can barely spell it), but I knew from the chart that something had developed that was a problem.

Sure enough, the HVAC professional found a leak, confirming a problem existed like the chart was showing.  While it wasn't a necessary piece of information, the chart even showed exactly what point in time the leak started.

I view my WEL monitoring system as a frivolous necessity.

Glad to see you got one of your problems fixed.

Best regards,

Bill

Engineer: Everything is in one cabinet. You're probably right about the leak, just as you and a couple other guys were right (and I was wrong) about the low refrigerant. We will monitor it closely for any performance degradation. I did not think there was a leak because the unit never did perform quite as well as the Premier 2 I had in the last house. It's been slacking off for two years now. But then again, maybe it just got progressively worse until hitting an intolerable threshold? What causes leaks? Is there a particular component prone to developing a leak?

Bill - I really REALLY like the WELSERVER concept. That being said, and without spilling too many beans, we're developing a system based on a vastly different approach. The functionality of this system is far beyond anything currently available. AS best we can find anyway. We've already qualified the technologies involved and have begun designing the concept testing platform. Stay tuned...

Now the WF unit does not run long enough to get loop temp measurements. Is it valid to turn up the thermostat a while to force it to keep running? Or will that skew the results?

John, take a look at http://www.agilewaves.com/ for competitive ideas.

Good luck!

Best regards,

Bill

Here's another one: http://www.powerhousedynamics.com/ .

Best regards,

Bill

Geogirl here adding a few comments a little late in the thread. Beware the "HVAC Guy" who is not trained in Geo. A geothermal unit is not an air conditioner, but is treated as such by many refrig. techs. It does not need charge added "seasonally" as some believe must be done with outdoor condensers. Did Monday's HVAC guy remove and then weigh in the full charge to nameplate? If not, then you will never know if it is over or undercharged. The refrig charge should be what is specified on the nameplate, because that is what the Mfr's performance tables are based on. The fundamental component in a geosystem is the earth source. We MUST know what is going on with the ground loop. That sounds like a no-brainer, but is often overlooked, e.g. by HVAC guys who don't know Geo. But I also thought that I saw it in this thread. No one commented on John's earth loop design or the temps reported. Now we know that there probably is a leak inside the box, but troubleshooting should always look outside the box, too. You have a ground loop with four vertical boreholes, three at 230' and one at 190'. That is a difference of nearly 20% on the 4th borehole. Often there can be dire consequences, e.g. inhibited movement energy. The longer circuits have higher pressure drop, and therefore slower or no fluid flow, thus no thermal transfer. The shorter loop has less press. and so receives more GPM, but has less pipe surface for thermal transfer. This is what I thought when I first saw your non-existent loop Delta-T. Does your loop have a reverse return header? What is your antifreeze and concentration? Granted, the fluid viscosity is not much of an issue at today's ground temps, but it is part of the overall picture. What are your loop pumps? Were all the pumps checked for operation during the troubleshooting? Are you sure that the header was configured properly? Were the vertical circuits and the header all pressure tested prior to filling? Was all the air purged? These are essential "system" operations that the conventional guys won't look at. They only look at the mechanical unit, which is so not what geothermal is all about. I'm not harping on the conventional techs, but maybe this (again) signals the need for more truly knowledgeable Geo professionals out there. Yes, you can turn up the t-stat to force the system to run for a period of time now in order to take new pressure & temp readings. It should run for 5 - 10 minutes to establish energy movement before you take the readings. If performance issues continue after addressing the internal leak, you might reexamine the ground loop, too.

"It's been slacking off for two years now. But then again, maybe it just got progressively worse until hitting an intolerable threshold? What causes leaks? Is there a particular component prone to developing a leak?"

Leaks are caused by manufacturing foulups (less likely) or installation foulups (more likely)

A responsible tech would have searched for a leak. Soapy bubbles is a low tech way. There are electronic leak detectors as well.

The TXV makes a system more tolerant of being under or overcharged, the bad side of which is that a leak may go unnoticed for awhile.

Geogirl - while I agree that weighing in a complete charge is the best way to insure proper charge, the subcooling method is a reasonable substitute if done carefully, and may have been the most cost effective method in this situation

I don't agree that the sky is falling on this loop. If John's system is heating his house on 5.6 amps at low stage, its probably doing OK. His Man J report (PM'd to me) suggests he won't need high stage until he makes planned additions to the house.

It is okay to jack the thermostat up a few degrees to get a long run interval. Done to excess (5+ degrees) it will slightly skew the data by reducing unit capacity and heat extraction, but not by enough to matter. Consider adding load by opening some windows as an alternative.

Uhhhhmm... Yes? I think?  Seriously though..  I have the distinct mis-fortune to live in a place where demand for techno savvy talent far exceeds supply. Why you ask? I moved here in the early 90's because the functional portion of my personal gray matter is significantly smaller then typical. It made me feel happy to finally be smarter then my neighbors.

The loop was installed by the WF contractor for this area. One would hope (?) that it gets installed correctly.  I watched the installation and listened to his complaining about the job being more work then he bargained for. Yada Yada Yada... He did install two manifolds as shown in documentation, although I must admit to having no clue as to what a reverse return header is.  I specifically wondered about the manifolds because they did not exist at my last house. At that installation, the loop was installed in a single series loop through four bore holes. I watched that installation as well because I have OCCS (Obsessive Compulsive Curiosity Syndrome). If it means anything, recollection tells that the shortest bore is Labeled "F" in the drawing.   I'm fairly certain of this because it is the one where he hit solid rock and could not get through it.  They were installed in order F, E, D and C. Don't know why they are labeled backwards.  He sent his helper to Georgia to get a different bit for his proud old (circa 1945) rig. OH, and some oil too.. That's as deep as he could go in that hole, so he moved to hole "E", then "D" then "C". My mind tells that there was a reason to place the manifolds where he did. To make up for a shorter hole he add length to the "F" in  horizontal distance from the manifold. I dug the trench from the house to the spot he told me to. This makes sense now. I had expected it to be at either "C" or "F" because of the previous installation but who was I to argue? I do understand the basic concept of different system characteristics having different resistance to liquid flow. It is somewhat analogous to OHMs law.

The installer came back the next day, hooked up the manifold and used the flush cart to fill the loop. He left it at about 25 psi, I think.  No idea what concoction he put in the water or how much. This supports the need for standardized documentation for loop/Geo installations....

The installer and I measured the distance to each bore from the left and right corners of my house for future reference.  The drawing is attached.  It does not indicate the depth of each bore. If it ever stops raining, I'll venture out, identify the locations of each bore and measure the distances between them. I'm sure there is some math formula to figure that out. With regret however, I must  admit that such a formula could reside only in the vacuum that would normally contain my missing gray matter. If there were some 90 degree angles to work with, Pythagorean Theorem would help.  Anyone know how to figure this out without getting soaked? And no, an umbrella is not what we're looking for...

Volume of refrigerant in the system? We don't know. I do know that he added a little refrigerant very slowly. He waited and studied his gauges. Added a little more and studied again.  There was very little adding and very much studying going on. He had me get the documentation from WF and look up temps in sub-cooling mode. I've no idea what the hell sub-cooling is, but like a good customer, I did as told. He compared this and that and was pleased with the readings.  He said leave it right there! I can say with absolute certainty that this unit has never ran this good. The unit runs maybe 4-5 out of 40-45 minutes. It was running almost constantly before last night.

I agree with your assessment that the industry needs more Geo expertise. General acceptance to the perceived "new" technology of ground source heat pumps is beginning to spread. As more people accept Geo, and fear it less, the demand will increase. As demand increases, experience in the field will increase.  There is no magic button to push that will influence all HVAC techs to run out and invest in formal training similar to yours. History tells us that it took a great deal of time for the dental industry in whole to incorporate Novocain into their everyday practice. GeoThermal, like any alternative to an established technology, is no different.  Until GeoThermal is widely accepted, we will just have to deal with the pain, just like the the people of old who had rotten molars.

My HVAC guy (a friend) is doing the best he can. I encouraged him to get on board the Geo train because I know his character. He is well suited for the task. Also I knew we would muddle through the growing pains as partners interested in mutual success.

John

Here are the new performance measurements:

Stage 1
Blower speed LED 2 which I "think" means speed 3 out of 5 = set for 850 cfm

EWT = 65.1
LWT = 60.9 Delta t w 4.2 degrees

EAT = 77.9
LAT = 98.5 Delta t a 20.6

Loop pressure in = 45 psi
Loop pressure out = 41

About the fan speed. It seems to me the fan speed would have great influence on the Air temp delta. But, the WF cooling and heating cycle analysis worksheets do not mention fan speed or air flow cfm... That's curious...

Something that makes measuring air temps in/out difficult is that; As the unit runs, the air in the house rises quickly. So the EAT rises too quickly to get a stable measurement on the digital thermometer. The same steady rise was experienced measuring the LAT which stands to reason. How the hek do the experts determine the delta if you only have one digital thermometer?

John

Normally we work on units that don't heat heck out of the house in just a few minutes...:>)

LED 2 corresponds to speed 3 out of 5.

Your numbers coupled with 5.6 amps for heating in low stage suggest things are fine for now, other than being oversized.

I'm curious to know if replacing the comfort alert module fixes the high stage issue, but shouldn't that be handled under warranty by a WF dealer?

We will most likely build a few small additions totaling about 400 sq ft. And the comfort alert, it's already ordered and it's easily replaced.

We turned on the DeSuperheater and will see how the WF unit heats water AND the house...

John

I don't think that I am inferring that the sky is falling on John's loop. It's just a necessary part of a complete picture. Going back to the initial posts on 11/27, I'm still wondering how the low loop temps, low loop pressures and air temps, led to an early theorizing of an internal refrig. leak. Just curious about what I missed that let us ignore the loop back then. The 5.6 amp thing didn't come out until later (engineer??) Too often there is the tendency to "condemn" the equipment too quickly. In this case the low refrig. situation was borne out. Back to John's loop. You indicated that the loop installer kept the "extra" pipe that wouldn't go into borehole F and laid it in the horizontal plane. He didn't just hack it off. That is good, means that F is probably equal length with C, D and E. You mentioned that he left the loop at 25 psi upon initial installation. After a few days that psi probably went down due to "pipe stretch". No kidding! Seriously, there is some "give" in the PE pipe and you will see a lesser pressure than when installed. One could initially start it at 30 - 40 psi because it will settle down. Also, just as leaks can occur later internally, so can they outside. If it fits with your OCCD, then you might collect all the data pertaining to the loop. But there's no need to get muddy to do it! I realize that your table shows the distance A and B of each borehole from the corners of the house. But in Geo Pythagorean's theorum is not necessary!! We love fluid flow calcs such as Hazen-Williams and Reynolds number that tells us if there is sufficient fluid velocity to turn on the movement of energy form the ground, of course depending on computers to do the calcs these days. On your diagram & table, IF A and B were analogous to the Supply and Return pipe lengths, then it would show that hole C is closer to the house on the supply and farther on the return (taking into account all the header pipe that makes up the reverse return). In looking for balanced flow the first take-off TO the loop must be the LAST to send its water back (hole C). Conversely, the LAST off (hole F), must be the first to send back. If the manifold is in the ground, then your S & R header pipes should be equal length from X back to the house. Cheers!

Geogirl, You're a lot of fun! I enjoy the technical explanations. But there are a few details not quite right...

On initial recordings of loop temps and pressures, the incoming temp is what I would expect it to be, approx 65-66 degrees. The pressure was around 45 psi. The installer left it at 25 psi and it did drop as you said it should. From past experience with another geo vert loop, I was told that it's best to keep the loop near 40-45 psi, but as long as it does not drop to zero it would work. So, a couple few times a year I check the loop pressure. The loop needed a few psi added (I think) twice since the install. Maybe I should keep a log...

The locations A and B on the table are reference points (corners) of my house. It's to give a permanent reference from which to locate the loop bores. The actual in and out loop piping is shown by the line from the house to the manifold location "X". The two are separated by a couple feet and the total distance is about 50-55 ft. The path curves because I started digging with the tractor 90 degrees from the house (straight out). The loop installer said NO NO! Make the trench go over there! OK... I curved around as he said. Did not make sense then, but learning about the loop lengths it makes sense now. If we break the loop into one series component and four parallel component, we find that the series component is not a factor in determining variances in the resistance to flow in each of the four parallel circuits. The series component adds to the overall resistance to flow in the system, but effects each of the four parallel legs equally. So.. If each parallel leg is "close" to the others, all legs would see similar volumes. Just like ohm's law! I think...


The original problem found was the extremely high temp in my water heater. 164 degrees! When that was reported to the forum, we were all focused on why. That's when Engineer clued in on the possibility of low refrigerant. His theory was right. The best I could come up with was moving the capillary tube off of the discharge line. Further reading since then tells me the capillary tube would have eventually had a hole ground into it due to vibration. Wait a minute...... It just hit me... I'll be back...

Visually I cannot see a worn place on the capillary tube where it was rubbing on the discharge line. Will have my hvac guy come back and look for a leak. All delta's remain the same and the unit it running very well. Actually make that: The unit is resting very well. It's a toasty 76 degree in here and the unit runs about once per hour+- for a few minutes (5-6?) on medium speed / stage 1.