david3394
Registered Users
New Member
Posts:5
 |
| 08/18/2009 9:28 AM |
|
Hello
I'm hoping that somebody here can help me , or steer me in the right direction on desuperheaters. I recently had a Climatemaster Tranquility 3 ton geo system installed with the electric strip backup heat. It is set up as a pump and dump system. The desuperheater is set up with a 50 gallon buffer tank into my 50 gallon electric water heater. The problem is that the desuperheater doesn't seem to be working. None of the lines coming from the geo unit to the buffer tank are even the slight bit warm. The installer told me that the lines need to be air-bled for about a week to get all the air out of them. He has installed bleeder valves in both lines, and I have been doing so every day. Still no warm water. My air conditioner is running quite often, so I should be getting some warm water out of the desuperheater lines, but just cold lines. If there is something that I can do to fix this (something very minor) I will . If it is something that I am doing wrong, I would like to know. Otherwise I'll have to get the installer back out. Even tho I might have to get him back out here, I would like to know the mechanics of how this system works, so i'm not fed a line of bull- - - t. If any one has any sugestions, I'm all ears,, please help.
Dave |
|
|
|
|
|
|
Bergy
Registered Users
Basic Member
Posts:116
|
| 08/18/2009 10:25 AM |
|
  Dave,
In the thread "It's Hot in Dallas!" page two has a post by me with a drawing for piping up a desuperheater. I don't know why I can't get it to post here...
You will notice, on the cold water "IN" pipe, there is a ball valve located BELOW the tee for the desuperheater. This makes purging the desuperheater lines quick and easy. Turn off that ball valve and open a hot water faucet. All the water WILL go through the desuperheater, re-inject into the bottom of the buffer tank, move through the main tank and out to the faucet.
On the 1/2" lines for the desuperheater there are two 1/2" ball valves. These are for servicing and flow balancing. If the unit ever needs to be serviced the ball valves can be turn off.
Balancing the flow through the desuperheater is very important. Most manufacturers want an 8~12* delta T through the desuperheater. Too much flow means not enough delta T, not enough flow means too high delta T. The lower ball valve can be closed down, a bit, to lower the flow and set the required delta T. Once done, the handles of both ball valves should be removed and stored inside the unit. This will prevent the flow rate from being changed accidentialy.
Finally, it is VERY IMPORTANT that any type of backflow preventer be removed from the cold "in" nipple and the dip tube. We draw water up through the dip tube, through the desuperheater and back into the bottom of the buffer tank. This insures no seddiments are drawn into the circulator's impeller.
Bergy
|
|
|
|
|
david3394
Registered Users
New Member
Posts:5
|
| 08/18/2009 11:29 AM |
|
Hello Bergy
Hey thanks for the quick reply, and now to pick your brain just a little bit more. I closed off that valve on the buffer tank, and turned on the hot faucett in the kitchen for about 4 minutes. The output line from the buffer tank to the main tank did start to feel warm. SHOULD THE 1/2 INCH LINE FROM THE DSH FEEL WARM?? Niether of the two 1/2 inch lines from the DSH felt warm.
I'm not sure what you mean by delta-t, but i'm think ing that it has something to do with throttling the water flow to the DSH. How do I set the delta-t??
Thanks Dave |
|
|
|
|
engineer
Registered Users
Veteran Member
Posts:1157
|
| 08/18/2009 2:26 PM |
|
The desuperheater should warm the water going through it by 8-12 degrees. In other words there should be a quite perceptible difference between water going in and water coming out. Your hand should be able to feel that difference.
If you are up north with really low (say <55 deg f) entering loop water, you may see little or no desuperheat recovery, although since you have a buffer tank you should get some. Yours may be disabled, misplumbed, or airlocked. It shouldn't take a week to get air out of it - mine worked on day one. |
|
Without data, you only have an opinion. |
|
|
david3394
Registered Users
New Member
Posts:5
|
| 08/18/2009 4:58 PM |
|
Hi Engineer
It might now be working, but I'm not positive. I'll explain my observations. In my first response to this thread, Bergy advised that I close the ball valve on the cold side of the buffer tank, and turn on a hot water faucett. I did that for 4 to 5 minutes. I'm thinking that should have broken any air lock that might have been in the DSH or the lines to the buffer tank. After Engineers reply, I went down to see if there was any difference in temp of the two 1/2 inch lines coming from the DSH. I could barely feel any difference. They both did feel about room temp. The cold water inlet from the well seemed a lot colder than the two 1/2 in. lines. I'm here in the thumb of Mich, and I've been told that my water temp is about 55 degrees. What I also checked after I felt the two 1/2 inch lines was to briefly open the high pressure safety valve on the buffer tank. Out of that pipe came water that felt like warm bath water. Is this an indication that my DSH is now working???
Thanks Dave |
|
|
|
|
a0128958
Registered Users
Basic Member
Posts:470
|
| 08/18/2009 6:09 PM |
|
... You will notice, on the cold water "IN" pipe, there is a ball valve located BELOW the tee for the desuperheater. This makes purging the desuperheater lines quick and easy. Turn off that ball valve and open a hot water faucet. All the water WILL go through the desuperheater, re-inject into the bottom of the buffer tank, move through the main tank and out to the faucet.
Bergy, this is exceptionally helpful. It makes it easy to purge the DSH lines very easy. And, it eliminates the need to install a 'Venting Waste Valve' at the highest point of the DSH line.
Unfortunately I didn't have your good advice when I plumbed my DSH. And thus, I have my 3/4" valve ABOVE the tee for the DSH. I'll have to fix this.
I've attached below your excellent drawing for the benefit of all others here.
Best regards,
Bill
|
|
Real time energy monitoring system at:
http://welserver.com/WEL0043/ |
|
|
engineer
Registered Users
Veteran Member
Posts:1157
|
| 08/18/2009 9:14 PM |
|
Posted By david3394 on 08/18/2009 4:58 PM
Hi Engineer
It might now be working, but I'm not positive. I'll explain my observations. In my first response to this thread, Bergy advised that I close the ball valve on the cold side of the buffer tank, and turn on a hot water faucett. I did that for 4 to 5 minutes. I'm thinking that should have broken any air lock that might have been in the DSH or the lines to the buffer tank. After Engineers reply, I went down to see if there was any difference in temp of the two 1/2 inch lines coming from the DSH. I could barely feel any difference. They both did feel about room temp. The cold water inlet from the well seemed a lot colder than the two 1/2 in. lines. I'm here in the thumb of Mich, and I've been told that my water temp is about 55 degrees. What I also checked after I felt the two 1/2 inch lines was to briefly open the high pressure safety valve on the buffer tank. Out of that pipe came water that felt like warm bath water. Is this an indication that my DSH is now working???
Thanks Dave
The top of the buffer tank may have been heated by expansion of water being heated in the main tank, so opening the T&P relief at the top of the buffer tank is not a definitive test.
Lack of a perceptible delta-T (temp difference) between inlet and outlet water at the DSH suggests it is not active.
Give it a day
|
|
Without data, you only have an opinion. |
|
|
Bergy
Registered Users
Basic Member
Posts:116
|
| 08/18/2009 10:05 PM |
|
Posted By david3394 on 08/18/2009 11:29 AM
Hello Bergy
Hey thanks for the quick reply, and now to pick your brain just a little bit more. I closed off that valve on the buffer tank, and turned on the hot faucett in the kitchen for about 4 minutes. The output line from the buffer tank to the main tank did start to feel warm. SHOULD THE 1/2 INCH LINE FROM THE DSH FEEL WARM?? Niether of the two 1/2 inch lines from the DSH felt warm.
I'm not sure what you mean by delta-t, but i'm think ing that it has something to do with throttling the water flow to the DSH. How do I set the delta-t??
Thanks Dave [/quote]
Dave,
You first need to make sure your system is plumbed correctly. It helps to make a drawing of some sort. If all the piping is correct, find out if the contractor removed the backflow preventer from the buffer tank. If all is OK, have the contractor back out to get it running and set the delta T. (temperature differential between the desuperheater's "IN" and "OUT" ports.) There may be dip switch settings that were not properly set up at start-up.
Running an open loop system requires added maintenance. Your coax heat exchanger will need to be back-washed every two or three years to remove mineral deposits.
Bergy
[/quote] |
|
|
|
|
a0128958
Registered Users
Basic Member
Posts:470
|
| 08/18/2009 10:42 PM |
|
Here's a picture on how the DSH is supposed to work, this one for the past 30 hours.
In my case, my DSH Delta-T is only about 1.5° (difference between red and blue lines), due to the high incoming water temp to the DSH, due to not have a buffer tank.
Hope this helps.
Best regards,
Bill |
|
Real time energy monitoring system at:
http://welserver.com/WEL0043/ |
|
|
david3394
Registered Users
New Member
Posts:5
|
| 08/19/2009 11:05 AM |
|
Hello again
Please bear with me, sometimes the concept escapes me, and this seems to be one of those times. First, my plumbing appears to be exactly as the illustration that is above. I understand that the delta t should be 8-12 degrees. Is this measurement between the two 1/2 inch lines that come from the DSH, and travel above near the ceiling, or where the two lines actually enter the DSH?? I may be wrong but the chart above seems to have a delta t of about 2 degrees. The chart also seems to show the water temp from the DSH into the HWT to be very close to the water temp coming out of the HWT. Am I reading this chart wrong?? If this is correct, than the 1/2 inch line that leads to the bottom of my buffer tank from the DSH should be very hot to the touch. Both of the overhead 1/2 inch lines seem to be room temp. One of the reasons I am so anal about what I should be feeling, temp wise, is if I have this guy come back out, I want to know exactly what I should have, and wheather he is lying to me just to get rid of me. Sorry for my lack of understanding here, but contractors have been known to take advantage of seniors. (well, close to senior...58)
Thanks for your patience Dave |
|
|
|
|
a0128958
Registered Users
Basic Member
Posts:470
|
| 08/19/2009 11:32 AM |
|
Posted By david3394 on 08/19/2009 11:05 AM
... the chart above seems to have a delta t of about 2 degrees.
The chart also seems to show the water temp from the DSH into the HWT to be very close to the water temp coming out of the HWT. Am I reading this chart wrong??
... the 1/2 inch line that leads to the bottom of my buffer tank from the DSH should be very hot to the touch. Both of the overhead 1/2 inch lines seem to be room temp.
Yes, the chart above shows a delta T of about 2 degrees. It's because I don't have a buffer tank. In your case you do, and thus the advise of 8 - 12 °F for a Delta T.
I posted the chart to illustrate concept. It needs to be interpreted and applied to individual situations. I apologize for confusing you.
I'm measuring Delta T at the DSH (at the point the copper lines connect to the outside of the GSHP unit).
Based on everything you've posted so far, I suspect your DSH pump is not operational.
Best regards,
Bill
|
|
Real time energy monitoring system at:
http://welserver.com/WEL0043/ |
|
|
heatoftheearth
Registered Users
New Member
Posts:44
|
| 08/19/2009 12:32 PM |
|
| there is a thermistor that activates a switch on the refrigerant line leaving the compressor, if the temp on that line stays below 135*F the switch wont close, desuperheater pump wont operate. I know some guys bypass that switch in cooling , and engage it for heating |
|
|
|
|
david3394
Registered Users
New Member
Posts:5
|
| 08/19/2009 2:47 PM |
|
Hello heatoftheearth
You possibly may have found my problem. This system was installed only a little more than a week ago. After the installer left, I discovered that the cooling wasn't working. I called the installer back out, and from the 5 flashes on the circuit board, he came to the conclusion that the system was going into a lock-out because of what he thought was an air flow problem. After a while, he discovered there was a bad thermistor. (a new unit with bad parts already, not a good sign) He jumped it out, and the system has been working fine. He said that he would come out to replace it when he got back from vacation. (he was leaving for vacation right from my house) This thermistor that he jumped out, could that be the thermistor that you are talking about???? And if so, after he replaces it, will my DSH work???
Dave |
|
|
|
|
Bergy
Registered Users
Basic Member
Posts:116
|
| 08/19/2009 5:06 PM |
|
Dave,
Your contractor is an IDIOT!!! You NEVER, NEVER, NEVER jump out any type of safety switch and allow the unit to run, jumping the thermistor could possibly be damaging the compressor. I would make note of which thermistor was by-passed, for how long, for what reason and by whom. Keep that information with your unit...just in case.
The thermistor he by-passed would not have anything to do with the desuperheater. The limit only controls the desuperheater's circulator and would not cause a lock-out condition.
Bergy
|
|
|
|
|
joe.ami
Registered Users
Veteran Member
Posts:1418
|
| 08/23/2009 8:46 PM |
|
I agree that jumping the thermistor interferes with the units ability to protect itself from harm if certain conditions occur and that a contractor exposes himself to trouble by bypassing it. Understand though that harm is not caused simply by jumping it out. Harm will only be caused if situations happen that the thermistor was designed to monitor.
It's easy for us to get excited when we hear about jumped out switches, but we don't have all the information available to us that your installer does.
I believe the thermistor we are talking about trips if fan coil is too cold. If your installer did all the appropriate tests to determine that it was faulty, then you will likely be fine. I also believe you have a redundancy with a low pressure switch (don't have the book handy to look up fault codes or know if we're talking about the same control).
Bad practice...yes. Real chance of harm...maybe not.
No connection with the DSH.
I also am not crazy about the comment that the DSH needs a week to bleed (it takes moments). However I'll again temper that with the reminder that we don't know what we don't know about your job and more than once we have all criticized an installation only to learn that a piece of the picture was not revealed to us.
You could look to see if DSH was hardwired (spade connectors are tagged in control department) but I would not activate it in case it is not bled. If you wish to look, turn off power first.
Good luck,
Joe |
|
Just a Mechanic;
Geothermal; Savings Underfoot |
|
|
Bergy
Registered Users
Basic Member
Posts:116
|
| 08/23/2009 9:55 PM |
|
Joe,
For an overnight fix to keep the unit running I would, under certain conditions, agree jumping a switch might be OK. I would never think the same of doing it and leaving for vacation!!
Bergy
|
|
|
|
|
joe.ami
Registered Users
Veteran Member
Posts:1418
|
| 08/24/2009 1:15 AM |
|
I'm not disagreeing with you Bergy, I'm just being cautious (for once). I still think there might be redundant protection here, but I also once freaked when a homeowner told me another company had jumped out a pressure switch on their ASHP pool heater. When I arrived I found that they replaced it with one teed in at the service valve which was the prescribed fix (vs opening the system). While it was true that the other guy had bypassed a safety, he bypassed it with a new safety and all was well :)
Unfortunately I expect a run of victims of new OJT contractors and your suspicions will often be true. Just hoping for the best here.
j |
|
Just a Mechanic;
Geothermal; Savings Underfoot |
|
|
jokin
Registered Users
New Member
Posts:8
|
| 08/28/2009 7:38 AM |
|
I must have had the same problem on my Tranquility 27. I too had a thermister go out... producing the 5 flashes on the control board. I think it was frostat alarm for the evap coil. It was tripping within a minute or two of compressor start in coolinng mode, but the evap wasn't even cold yet or even wet. I cut the jumper to disable this alaram and its been working great ever since. I wouldn't mind getting a new thermistor though. Anyone know a cheap source for Climatemaster 27 thermister sensor (I think its FP1 or FP2) ?
|
|
|
|
|
joe.ami
Registered Users
Veteran Member
Posts:1418
|
| 08/28/2009 7:55 AM |
|
Posted By jokin on 08/28/2009 7:38 AM
I cut the jumper to disable this alaram and its been working great ever since.
Hold old is the unit? All parts have 5 year warranty (or more). Contact your installer. You have voided any remaining warranties.
Joe |
|
Just a Mechanic;
Geothermal; Savings Underfoot |
|
|
maustin
Registered Users
New Member
Posts:3
|
| 09/06/2009 8:29 AM |
|
| Are you sure contractor hooked up the electrical connection for the desuperheater. If I remember correctly they are not hooked up inside unit because not everybody uses them. If they are not hooked up the pump will not work. |
|
|
|
|