Nicky:
My observation / my belief on the chiller :
a) Leave aside the whole saga of an additional thermostat with external sensoras I mentioned in my previous post, I don't care whatever brand of chiller, as long as the temp sensor is not taken from the tank, I don't think it is accurate.
b) your flow rate is slightly on the low side . If you are comparing your current setup (flow rate) vs a higher flow rate (faster pump,etc) , the later one cooling result is much more effective with shorter time. You can see a big difference in the time in term of cooling result especially with a external sensor.
c) You kept the chiller in the cabinet, and a lot of the hot air from the chiller will eventually suck in again, and the heat exchange will not effective under this condition.
Probably a bad thermal sensor for the chiller if your "feel" test is cold enough.Originally Posted by Nicky
How about the inaccuracy of build-in thermometer? Do you know why it is showing 27.xC when my external one is showing 25C?
Surely if the flowrate is too slow it should be the reversed, right?
Regards
Peter Gwee
Plant Physiology by Taiz and Zeiger
Your point A is valid, I think.
This, together with your point A, are good reasons for having an external sensor. Another thing to learn about this chiller saga is that, too big a chiller for a tank is actually counter productive.
I'm still trying to figure how your external sensor works. Does it work like the following? Do you have a picture to show us how it all connects together?
- The external sensor sense the temp of the water, and it is connected to the 'power-socket' from which the chiller derives its electrical power. So when the sensor thinks it is not time to operate, the chiller has zero electrical power and it is totally switch off, even without power to the LCD display. Then when the sensor thinks it is time to work, it provide power to the attached 'power socket'. As far as the chiller is concerned, it is like someone has just turn on the switch. For this to work the temp setting of the chiller must set low (say 15C). And even if the external sensor accidentally drops out of the water, the chiller will cut off its operations when the 'internal reservoir' reaches 15C. Am I right?
My cabinet is designed for air circulation lah.. it does not have a backing; you can see my back wall from the picture. And all 3 other sides of the cabinet are louvered. Plus my tank is right next to my main door and so air circulation in that area is very good. Good thoughts though..
My Resun chiller has an offset adjustment to calibrate the thermometer. Does yours have one? Maybe you need to calibrate the temperature reading.How about the inaccuracy of build-in thermometer? Do you know why it is showing 27.xC when my external one is showing 25C?
Surely if the flowrate is too slow it should be the reversed, right?
BC
I don't think I have this problem with my artica chiller when I was using it, it was set to 26 most of the time, and compared against the floating alcohol type thermometer...a) Leave aside the whole saga of an additional thermostat with external sensoras I mentioned in my previous post, I don't care whatever brand of chiller, as long as the temp sensor is not taken from the tank, I don't think it is accurate.
--
meanwhile, nicky, have you tried placing chiller outside the cabinet and see if that affects anything?
Don't think this chiller allows calibration of internal thermometer. I thought this should be quite a basic requirement. It is not reference to in the instruction.
There is only 3 buttons; Set, Up and Down.
Maybe there is a special combination that can set the internal thermometer.
Will wait for the service man of the distributor to come to my house and comment.
Because the cabinet is place in area where there are good air flow, I honestly don't think it will make any difference but if the service man (to be sent by the distributor) comment on this I have all the hose ready to effect the change on the spot.
Mine has 3 buttons too. I think you need to press one of the buttons (should be the set button) and hold.
BC
Nicky,
I think the problem is at the flowrate. Suggest you get more flowrate to confirm the issue. For china made chiller, usually you will get accurate performance provided the flowrate is higher than what's their recommendation. Your eheim 2028 is stated to be 1200-1300L/hr but due to your piping length and media .... etc i suspect maybe flowrate at 1000L/hr.
I find that's the same with Resun chiller. With my Resun 1/10HP chiller .. i'm using a 1200L/hr Eheim 1250 pump to drive it. I have tried to use external reactor from NA and it slowed the flowrate .. maybe to 800L/hr and the chiller kicking in seem less consistent already.
That will allow me to change the temp setting, not calibrating the thermometer. Hiaz..
Mind you , even my setup with a 2262 Eheim (pump + canister) with a pump flow rate of 3400L, because with all my PVC piping etc, the flowrate reduce drastically. One of the occasion I noticed my chilling time took longer, then I noticed my flowrate reduced due to clogging in the canister. After clean up the filter mat, the flow rate improved and the chilling time reduce again.
Re. the problem of temp reading fluatuation, I begin to think it is the flow rate issue. But I like my current flowrate in my tank now. So the next step is to source for a external sensor. That should fix the problem. I think the setup should be as shown in the bottom..
But the thermometer is definitely not calibrated properly. When the chiller is not running, my cheap thermometer is showing about 2 to 2.5C LOWER than that display on the chiller. That I definitely want it fixed because it is simply not acceptable that it is not accurate and yet cannot be calibrated by user. On the day when the service man is here, I will set the temp real high on the chiller (so that it will not kick start). That will make the chiller-reservoir water and the aquarium water to be the same temp. Any difference is calbration issue.
have you just try offsetting the temperature?When the chiller is not running, my cheap thermometer is showing about 2 to 2.5C LOWER than that display on the chiller.
ie: if your desired temperature is 25, and the chiller when display 25 actually means 23, then calibrate your chiller for 27
If I'm buying a 2nd hand chiller then I will be willing to accept this type of imperfection. At this point I like to hear what the distributor has to say and how they are going to fix my problem. I'm going to stick with my 1 year warranty entitlement.
When I was reading the following product review some weeks back, I remember very clearly that the reviewer compare the external thermometer reading versus the in-build thermometer and comment something like 'whoever say build-in thermometer is not accurate?'.. but I can't seemed to find that statement now. Hmmm... maybe it is a bias review.
http://www.sgreefclub.com/forum/inde...pic=50052&st=0
what is your definition of accurate in this case?
just because the temperature sensor does not measure your tank water temperature, it is not accurate?
temperature sensor accuracy should be determined at the point where it is installed.
thomas liew
maybe you can check the manual to see whether the temperature sensor is mounted at the chiller inlet (hot) or outlet (cold). if the sensor is mounted at the inlet, that could explain the higher temperature displayed by the chiller.
why not shutdown the chiller for a day or 2. then check if there is still a huge difference temperature readings from your chiller and "cheap thermometer". btw, which do you trust more; "cheap thermometer" or chiller display?
thomas liew
What don't we just sit down and drink a cup of tea and eat a "pao"?? And put all this sensor n Temperature thingy aside....
Nicky ,
In case you are interested in the FOX thermostat, the URL for the one I am using FOX-1004
http://www.foxeng.co.kr/english/menu/003/sub2.html
Sorry, I did not DIY the way you drew , that is what Tan (Bioplast) having. I replaced my internal thermostat with the Fox-1004, but still I prefer the combination method (internal and external).
Nicky,
I think i have seen those device before and if i didn't forget, it was initially DIY by folks in some local marine forum.
Below is my own interpretation/understanding of how this device work. The idea was that the device will power on/off the chiller and the chiller is suppose to be set the kick in temperature lower than the device.
For example :
Temp set on device to kick in : 24 degree
Temp set on chiller to kick in : 18-23 degree. Must be lower than 24. Having 18 is better.
In this way for example if the tank temperature is 25 degree, the device external probe will sense it .. and power on the device where the chiller power is connected to. The chiller being powered on and sensing a temperature of 25 (remember it was set to 23 and lower) will straight away kick in and chill the water.
When the tank temperature as sensed by the external probe is 24 degree, it will just power off supply to the chiller. Hence the chiller stopped chilling even though it was set to cool to 18 degree.
But i wonder all this powering on and off will wear out the chiller. My experience with my chiller is that once it was power on .. it seem like it take some time to startup and start cooling (a few mins). While it was not in use it was always in a some sort of standby mode while waiting for the next kick in.
Nick,
I just called the boss. Tml I will go down to neg the price. I think he is out with his family.
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