What is the main purpose of getting an external thermostat?

[vernonlcm]

I mean if your chiller is working fine, it is not neccessary to get the above right as chiller has it built in thermostat. Does it have additional advantage of getting this external thermostat???

[koolman]

I mean if your chiller is working fine, it is not neccessary to get the above right as chiller has it built in thermostat. Does it have additional advantage of getting this external thermostat???

To my understanding, chiller stated the degrees that you would like your tank to have.. To have a external thermostat, it will tell you the actual temp of your tank.. Atmosphere from the external and your chiller will tell you a different temp in your tank.. Do not quote me if I am wrong.. Just my knowleadge of fish keeping..

Cheers
Koolman

[Shadow]

Because the one you want to cool down is the temperature inside your tank. Standard chiller design is only measure the temperature inside the chiller heat exchange chamber. Thus if your pump flow too slow, the water inside the chamber is much cooler than the water temperature inside your tank. That will cause the start stop problem and your electric bill will go up.

[vernonlcm]

Because the one you want to cool down is the temperature inside your tank. Standard chiller design is only measure the temperature inside the chiller heat exchange chamber. Thus if your pump flow too slow, the water inside the chamber is much cooler than the water temperature inside your tank. That will cause the start stop problem and your electric bill will go up.

Fully understand why you had stated. Thanks for the clear clarification. Cheers.

[eviltrain]

but is there anyway to connect the external thermostates to the chiller? do we have to open up and connect it?

[Shadow]

Thermostat (not really sure what you call it, thermostat or external temperature controller) normally is a box that connect or disconnect the power to your chiller.

So your chiller is actually plug into your thermostat box. you might need some modification to add the 3 pins connector.

The one that must open is just a sensor. It is cheaper (~$15) but it won't work on vernolcm problem where you can't event set the chiller.

[christopher.wtc]

I mean if your chiller is working fine, it is not neccessary to get the above right as chiller has it built in thermostat. Does it have additional advantage of getting this external thermostat???

In my opinion, I will think an external thermostat is unnecessary If you have a chiller that has a temperature error calibration. Measuring the true temp from the tank and compare it to the temp shown on the chiller. If there is a difference in temp, you could calibrate your temp error function and set it similar to the true temp of your tank.

I did read somewhere, the purpose of an external thermostat was to take over temp control of the chiller. Different brands of chiller kicks in at different temp, some after 0.5 degree, some after 1 degree. With an external thermostat, after your chiller reaches the temp for it to kick in, the thermostat holds the chiller back from kicking in, waiting to see if temp falls back to idle temp, this rarly happens in Singapore due to our climate condition, but it does happen else where. If you understand this method of using an external thermostat, you will see that this way, you save electricity thus the purpose of an external thermostat.

Good luck bro.

[blue33]

I think you got it wrong! The reservoir in the chiller is so small, the temperature fluctuate inside is faster than the tank temperature, whereas tank temperature dont fluctuated so fast. Even if you calibrate to true temp, the kickin would still be fast due to small reservoir and heat exchange inside the chiller, still you wont get the true temperature of your actual tank temperature. Dont forget that the heat exchange is built inside the chiller also, it does affect the reservoir temperature inside. Thats why alot of people would recommend you to get faster flow rate canister or pump, but not many people want to create a tornado in their tank, the reason why people recommend a faster flow rate, cause the heat build up inside the chiller is fast.

Thermostat not necessary unless is spoil, sensor is a must have, unless you dont mind the electricity bill and the lifespan of the chiller. If you have try on the external sensor you would find the great difference of installing a external sensor, whether the chiller is branded or not branded. Of course using branded one, the parts are long lasting except that if the sensor is install externally and into the tank, but that would cause some problem to manufacturer due to customer negligence that damage it.

In my opinion, I will think an external thermostat is unnecessary If you have a chiller that has a temperature error calibration. Measuring the true temp from the tank and compare it to the temp shown on the chiller. If there is a difference in temp, you could calibrate your temp error function and set it similar to the true temp of your tank.

Good luck bro.

[Shadow]

yes-yes that exactly, because the camber is small the water inside will cool down very fast the bigger the 'hp' the faster it cool down. If your pump flow is too slow, chiller will think that the set temperature have been reach, So the compressor will turn off but few minutes later after all the water inside the chamber have been change to new warmer water from the tank, compressor on again.

[christopher.wtc]

I think you got it wrong! The reservoir in the chiller is so small, the temperature fluctuate inside is faster than the tank temperature, whereas tank temperature dint fluctuated so fast. Even if you calibrate to true temp, the kickin would still be fast due to small reservoir and heat exchange inside the chiller, still you wont get the true temperature of your actual tank temperature. Dont forget that the heat exchange is built inside the chiller also, it does affect the reservoir temperature inside. Thats why alot of people would recommend you to get faster flow rate canister or pump, but not many people want to create a tornado in their tank, the reason why people recommend a faster flow rate, cause the heat build up inside the chiller is fast.

Thermostat not necessary unless is spoil, sensor is a must have, unless you dont mind the electricity bill and the lifespan of the chiller. If you have try on the external sensor you would find the great difference of installing a external sensor, whether the chiller is branded or not branded. Of course using branded one, the parts are long lasting except that if the sensor is install externally and into the tank, but that would cause some problem to manufacturer due to customer negligence that damage it.

Agreed with your point, no doubt that temp do not fluctuate fast in the aquarium. I will agree too that getting the exact temp reading on the chiller for the aquarium water is impossible however getting it close enough is good enough. That was what I have explained about the temp error calibrating function to show that an external thermostat is unnecessary. To refresh on my point, I said I zmade check on the temp of my tank first before using the result to calibrate on the chiller. Like what you said the "fluctuation difference" will be resolved by calibrating the chiller temp. Course having a faster flow rate to circulate to replace the water in the chiller will give more accurate temp reading of the aquarium. I find it hard to believe that temp fluctuation/difference in tank and chiller was not considerer by chiller manufacturers, I am with doubt if they knew about it, wouldn't they sell and earn more if they sold the chillers with their external thermostat.
This is my point and you got yours, let the one who ask the question decide what is good.

[blue33]

I think you still get it wrong. What i mean is the often kickin period. The tank may be still showing at 25ºC but the sensor inside the chiller would be showing 27ºC and it starts to kickin more often and unnecessary, this is waste of electricity. No matter how you calibrate, the kickin is still very often. You should try it yourself and see the result you can get? I myself try it and realize the result difference so much. We prove by result, not by theory itself. You can ask around those using external sensor and without external sensor and see what they'll tell you.

Manufacturer is not stupid but they rather prefer the machine to kickin often than installing a external sensor, which would be easily cause damage by the user. If you are the Manufacturer, and by installing the sensor inside the chiller would take you maybe few years to spoil the chiller than installing a external sensor which maybe take you much shorter period to spoil(cause by the negligence by user due to external wire/sensor expose), which would you opt for? Btw they install sensor inside is also to beautify the chiller, packaging purpose. Parts appear outside of the chiller tends to cause damage by the user more easily.

Agreed with your point, no doubt that temp do not fluctuate fast in the aquarium. I will agree too that getting the exact temp reading on the chiller for the aquarium water is impossible however getting it close enough is good enough. That was what I have explained about the temp error calibrating function to show that an external thermostat is unnecessary. To refresh on my point, I said I zmade check on the temp of my tank first before using the result to calibrate on the chiller. Like what you said the "fluctuation difference" will be resolved by calibrating the chiller temp. Course having a faster flow rate to circulate to replace the water in the chiller will give more accurate temp reading of the aquarium. I find it hard to believe that temp fluctuation/difference in tank and chiller was not considerer by chiller manufacturers, I am with doubt if they knew about it, wouldn't they sell and earn more if they sold the chillers with their external thermostat.
This is my point and you got yours, let the one who ask the question decide what is good.

[Shadow]

In my opinion, calibration is useless. It is just an offset.

Chiller will kick in based on temperature different, some 1 degree while other 2 degree different. As long as the temperature different between water temperature and set temperature is reached it will kick in.

Manufacture is not wrong, that is why they put recommended flowrate

back to vernolcm issue, base on his description, his chiller electronic is spoiled. Unless he find someone to fix it or get new one, he will need external temperature control

[BFG]

Christopher.wtc, I think you have not catch on to what Blue33 and Shadow are trying to point out. Calibration has nothing to do with the constant switching on and off of the chiller. Even if calibration is way off, the chiller will still think it is the right temperature, there's no intelligence system built into the chiller.

What is happening is that when using the external temperature sensor, the chiller will chill the WHOLE tank to the desired temperature being set. If you did not use the external temperature sensor, you are only chilling the temperature in the chiller chamber only.

[Jimmy]

Thermostat (not really sure what you call it, thermostat or external temperature controller) normally is a box that connect or disconnect the power to your chiller.

So your chiller is actually plug into your thermostat box. you might need some modification to add the 3 pins connector.

The one that must open is just a sensor. It is cheaper (~$15) but it won't work on vernolcm problem where you can't event set the chiller.

With regard to the pins connector, my current built in sensor is using a 2pins connector. I believe external sensor is using 3pins connector? So what kind of modification you referring to? Is it difficult? Or just connect the 2 required wires into the existing connector and ignore the earth wire? Thanks!

[Shadow]

my external sensor use 2 pins only

[blue33]

same for me ... 2 pins only. Did you get the correct stuff?

[Jimmy]

Thanks for the replies. I haven't buy the external sensor yet but was confused by shadow's comment on "you might need some modification to add the 3 pins connector". So what 3 pins connector you referring to? My chiller HC-100 is using 2 pins connector, which mean I can just 'plug and play' the external sensor? Many Thanks!

[Shadow]

3 pins power supply

[pengtsin]

Thanks for the replies. I haven't buy the external sensor yet but was confused by shadow's comment on "you might need some modification to add the 3 pins connector". So what 3 pins connector you referring to? My chiller HC-100 is using 2 pins connector, which mean I can just 'plug and play' the external sensor? Many Thanks!

To get back to the main question, another reason for running an external sensor/switch in series with your chiller or heater is in case the primary thermostat fails.

You might think this is not going to happen (and so did I) ... but I just almost had a tank of boiled Discus because a *new* heater's thermostat did not cut off. Same might happen to a chiller's thermostat -- and you'll have frozen fish instead. I'm running that tank with an external thermostat set to switch a new heater.

My 2 cents.

[Jimmy]

3 pins power supply

sorry, misread your reply. now i know what you referring to. thanks!