Ask your chiller related issues here

[ihavtats29]

Quote:
Originally Posted by TheH View Post
How do you blow out the condenser coil?
a can of compressed air will do fine on small coils , but if the coil is badly impacted more preasure will be needed , they make a compressed air cylender that you can refill at any air pump


in case you didn't know, the condenser is the coil gives off the heat that has been taken away from the water. In a home split system, it would be the unit outside with the fan.

that is not correct . basic refridgeration 101 the condencer coil does exactly what it says, the compressor , compersses a lolw pressure cool gas into a high pressure hot gas it then moves to the condencer coil that converts the hot gas to a warm liquid it movesot the evaporator coil frist going thru a expansion devise changing the warm liquid to a saturated vapor in the evaporator coil the air or water flowing across the coil is where you get you cooling from

 

[A Reef Scene]

Can you increase the cooling of the chiller by adding a larger flow thorugh coil or would just make the system not work as hard to pull the temp downn.

 

[ihavtats29]

Can you increase the cooling of the chiller by adding a larger flow thorugh coil or would just make the system not work as hard to pull the temp downn.

too much flow will not allow the temp of the water to change as it is needed, you should use the amount of flow recomended by the manufacture for your chiller not exceeding thier specs

 

[ihavtats29]

Hello fellow chiller user!

If you have a problem with the chiller that keep switching on and off all the time, a good fix is to have an external temperature probe modification done to your chiller. Normally, a chiller will monitor the water temperature inside itself but this is a flaw. While the water in the chiller compartment may reach the desired temperature, the tank water might have a different temperature reading altogether, which is always higher than the one in the chiller.

Having an external temperature sensor located in the sump, it will measure the water temperature of the tank instead of the water in the chiller. This is a more accurate temperature reading as it is the aim of the chiller to cool the water in the tank as oppose to chilling the water in the chiller compartment.

The issue with chiller turning off and on is that sometimes folks bought the wrong pump, either it is under powered or too powerful. An under powered pump will cause the water in the chiller compartment to be chilled faster and while the water in the chiller compartment reaches the desired temperature,the chiller will switch off for a moment until that compartment is replaced by more water which is always at a higher temperature than in the chiller compartment and the chiller will switch on again.

An over powered pump will continue to push water into the chiller but due to the higher water flow, the chiller would have less contact time to chill the water making it longer to chill the tank water.

But, by having an external temperature sensor in the sump, the chiller is chilling the whole tank water volume. When this sensor reaches the desired temperature, the chiller will switch off it's chilling process for quite a time while the total water temperature naturally rises due to other factor such as heat from pumps and such. From this perspective, this is a better option of chilling the tank water. This is how I have mine configured to.


Hope this helps!

Good answer , the only issue with a remote temp sensor is that if your pump fails the chiller will keep chilling and will freeze the water in the heat exchanger causing the exchanger to crack, if you put a remote sensor on the system you should add a flow switch in the entering water line with a low voltage relay and transformer controling the mainpower keeping the chiller from running with out a pump, about a additional $40 that will save you from having to replace your chiller due to a cracked exchanger

 

[ihavtats29]

Thanks BFG,

I think that the external temp probe would be a great addition.
But I still have the same problem in that if the chiller can cool the tank 2 degrees in say for example 1 hr, and the tank rises 2 degrees in say 4 hrs during the day with lights on I still have the temp in the tank going from 79 to 77, twice during the day.

I would think that I would have 2 options
1. Resize the chiller smaller, to not cool as fast?
2. or, I was hoping to reconfigure the temp setting in the chiller to come on
at .5 deg above set point, and shut off .5 below set point?

Maybe we are better off without the chiller, where the tank went from 77
to 81 once a day?

the temp diferential of your controler is programed by the manufacture for a +/- 1 degree diferantial a smaller chiller will do the same depending on the controler used , research your chiller purchases with the manufacture before buying a new one to see if you can control it the way you want it. you may not even need a chiller try a clip on desk fan for your sump , it keeps my 60 gal at a stable 78 and is plugged in my lighting timer to come on when my lights do

 

[ihavtats29]

I have a 1/3hp JBJ chiller on a 180-gl. sps tank. It takes a long time (sometimes 3 hrs) to take the temp. down 2-degrees. I had a local HVAC repair person thoroughly clean the condenser and heat exchanger; both of which were very dirty and now they are spotless. I hook it up yesterday and it still takes a very long time to come down 2-degrees.

I performed a static test on it last night and it takes about 20-minutes to come down about 2-degrees and then does not come down anymore than say from 77 to maybe 75.8 degrees.

Do you know what the problem might be from here? Can it be the compressor? He said the freon should be fine and that there were no signs of leaks? He did not want to test for freon because he stated he would have to pierce the system to test???

Can someone please chime in and let me know what my next step should be? Can I replace a compressor or is it cost prohibitive???

Thanks in advance for any help......

it could be the location of the chiller if the chiller is under the stand you could be recirculating the hot air off the condencer coil ( stacking air). try setting it outside the stand. when you put a chiller under a stand it should be in its own sealed compartment with a cut out the size of the coil up against the cut out and a 4'' cooling fan blowing into the compartment , also a min of 4'' off the wall, if the chiller does not have good cool air flow it will not be able to cool correctly, depending on the chiller and if its american or a jap made compressor and btu's and amp drawn can be closely matched then the compressor can be replaced cost effective not at all, unless you can do it your self it would most likely cost as much as a new chiller or more ,

 

[tegee]

ihavtats29...........

What are your thoughts on this???

I have a 1/3hp JBJ chiller on a 180-gl. sps tank. It takes a long time (sometimes 3 hrs) to take the temp. down 2-degrees. I had a local HVAC repair person thoroughly clean the condenser and heat exchanger; both of which were very dirty and now they are spotless. I hook it up yesterday and it still takes a very long time to come down 2-degrees.

I performed a static test on it last night and it takes about 20-minutes to come down about 2-degrees and then does not come down anymore than say from 77 to maybe 75.8 degrees.

Do you know what the problem might be from here? Can it be the compressor? He said the freon should be fine and that there were no signs of leaks? He did not want to test for freon because he stated he would have to pierce the system to test???

Can someone please chime in and let me know what my next step should be? Can I replace a compressor or is it cost prohibitive???

Thanks in advance for any help......

 

[ihavtats29]

either what i posted above or there is a leak some where in the system , most leaks will be found at the flare connections going into the heat exchanger, the compressor can be check by amp draw getting close to the rated running amps also feel the suction line on the compressor commoni from the heat exchanger it will be insulated and should get cold when running located near the top on the side of the compressor, carefull not to grab the discharge line going to the condencer coil for it will be HOT, if the suction line is not getting cold there is most likely a refridgerant leak, slim odds that the compressor is not pumping

 

[cee]

What are typical high and low pressures in the system?

 

[ihavtats29]

it depends on the type of refridgerant and load the chiller is under along with ambiant temps, an average r-22 system would have a low/ suction preasure around 65psi and the high/ discharge/liquid line preasure between 175 and 225

 

[BFG]

Good answer , the only issue with a remote temp sensor is that if your pump fails the chiller will keep chilling and will freeze the water in the heat exchanger causing the exchanger to crack, if you put a remote sensor on the system you should add a flow switch in the entering water line with a low voltage relay and transformer controling the mainpower keeping the chiller from running with out a pump, about a additional $40 that will save you from having to replace your chiller due to a cracked exchanger

Yup, the pump is the only factor that could failed and that is avoidable by using a work horse pump like an Eheim pump. As for the float switch, I'm not a technical wizard by trade so I can't fiddle with stuff I'm not familiar with. The modification was done by my air-con technician. I have since upgraded to a Mitsubishi air-con compressor with rubber coated coil in the sump together with an external temperature probe. The worry of the chiller freezing is over with this upgrade but still the achilles heel is still in the pump.

 

[ihavtats29]

not a float switch a flow switsh , it sences water flow thru the pipe gong into the chiler, basicly its a pvc t that is inline that has a no/nc switch with a paddle on it when the water passes over the paddle it closes the switch and allows the chiller to run when water flow is lost the switch will turn off the chiller, it is what is used on all comercial chillers and boilers as a main safty

 

[tegee]

ok ihavtats.......first THANK you very much for your help so far.

Here is the deal with my jbj 1/3hp chiller. When a perform a static test the temp now drops pretty quickly from 79 to 62 degrees in about 5-minutes. The compressor feels cool to the touch and the suction line into the compressor is also noticeably cool, while the outlet tubing to the condenser is hot as you described. All good signs I would assume. I do want to note that I had a local HVAC guy thoroughly clean the condenser and heat exchange, so we are good there.

Ok, now to the good stuff. I let the chiller completely cool down from the morning static tests. I have now lights on, only my 3-external pumps running, etc. Had the chiller kick on at 79 degrees and now the chiller has been running for 30-minutes and it is still running at 79 degrees. The compressor is now very hot to the touch and the suction line is only slightly cool to the touch not very cold like it was during the static tests. I am going to say that it will take at least 2-hours to cool down 2-degrees.

BTW: I pulled the chiller out into open area by adding 4'+ feet of 3/4" tubing so it is not stacking its own heat, which was a great suggestions. Although not in a closet or under stand, it was definitely in tight quarters.

What do you think can be the problem? Is this chiller simply under rated for a 200-gl. sps tank. The HVAC guy told me that if the compressor gets too hot (overworked) there is a safety type switch that trips the compressor so it does not overheat. Can that be happening. I have a Blueline recirculating pump hook up that is rated for 1200-gls/hr and when I did the RC head loss calculations it states that it is only pumping about ~500-gls./hr with all the ells, ballvalves, etc.

Please advise as to what I should check next........MANY THANKS again for all your help to date.

 

[checkx1]

Any insight on good quality chillers and ones to avoid. Looking to get one for total water
volume of 60g.

 

[BFG]

Tegee, what is directly behind the chiller now? There should be about a couple of feet or more behind the chiller so the hot air could dissipate. If you place it right near a wall, the heat might also be recycled back into the chiller. You could raise the chiller and place near the window so that the hot air is vented outside.


Checkx1, chiller from China are cheap and ok in my book, had used them before, only that they should have an external temperature probe modification done on them. I had one WITHOUT the modification and it over worked and broke down. A friend of mine has the same model WITH the modification done and is still running nearly a year now. My upgraded air-con compressor chiller is also modded with the external temperature probe. As long as you take care of the chiller by giving it space to vent hot air away from it and regular maintenance on the condenser/heat exchanger, you might have a worry free chiller for a few years and if they broke down, replacing one isn't going to break the bank. Arctica and Teco are a good brand but you need to check for their after sales service.

1 thing I remembered now is to check for stray current from the mod. The technician doing the modification might not do a good job so checking this is absolutely important. Mine is free from stray current in the water.

 

[ThaNgBOm321]

that is not correct . basic refridgeration 101 the condencer coil does exactly what it says, the compressor , compersses a lolw pressure cool gas into a high pressure hot gas it then moves to the condencer coil that converts the hot gas to a warm liquid it movesot the evaporator coil frist going thru a expansion devise changing the warm liquid to a saturated vapor in the evaporator coil the air or water flowing across the coil is where you get you cooling from

heh, your right, I was just plotting things down before i had the change to reread by thermal dynamic. Good thing someone knows what they are doing. (happen to be type 3 universal myself but i suck at it)

YzGyz

 

[ihavtats29]

ok ihavtats.......first THANK you very much for your help so far.

Here is the deal with my jbj 1/3hp chiller. When a perform a static test the temp now drops pretty quickly from 79 to 62 degrees in about 5-minutes. The compressor feels cool to the touch and the suction line into the compressor is also noticeably cool, while the outlet tubing to the condenser is hot as you described. All good signs I would assume. I do want to note that I had a local HVAC guy thoroughly clean the condenser and heat exchange, so we are good there.

Ok, now to the good stuff. I let the chiller completely cool down from the morning static tests. I have now lights on, only my 3-external pumps running, etc. Had the chiller kick on at 79 degrees and now the chiller has been running for 30-minutes and it is still running at 79 degrees. The compressor is now very hot to the touch and the suction line is only slightly cool to the touch not very cold like it was during the static tests. I am going to say that it will take at least 2-hours to cool down 2-degrees.

BTW: I pulled the chiller out into open area by adding 4'+ feet of 3/4" tubing so it is not stacking its own heat, which was a great suggestions. Although not in a closet or under stand, it was definitely in tight quarters.

What do you think can be the problem? Is this chiller simply under rated for a 200-gl. sps tank. The HVAC guy told me that if the compressor gets too hot (overworked) there is a safety type switch that trips the compressor so it does not overheat. Can that be happening. I have a Blueline recirculating pump hook up that is rated for 1200-gls/hr and when I did the RC head loss calculations it states that it is only pumping about ~500-gls./hr with all the ells, ballvalves, etc.

Please advise as to what I should check next........MANY THANKS again for all your help to date.

the safty the tech was refering to is thermal protection if it over heats is cuts off the common leg of power to the compressor untill it cools down enough, if that were the issue the compressor would not run, with coils clean and plenty of breathing room its not a over heating issue , it seems to me there is nothing wrong with the chiller but maybe too much heat load for it to handle. 1/3 hp chiller = 1/3 ton = 4,000 BTU
1 hp /ton = 12,000 btu's
you can calculate you btu heat out put by getting your total wattage of your equipment ballasts , pumps , heaters exct.... multiply that # by 3.5

then your lighting in wattage total x 4.25

add the 2 totals together that is the amount btu's your tank is putting off

for example if your lighting were 800 watts and the total of the rest of your equipment were 520 watts
800x4.25= 3400 btu's
520x3.5= 1820 btu's
totals 5220 btu's

you would need a 1/2 hp or 1/2 ton chiller to handle the load

 

[ihavtats29]

Any insight on good quality chillers and ones to avoid. Looking to get one for total water
volume of 60g.

to be honest current makes a decent chiller for the cost, well the dont make it they just put thier name on it, trade winds can be costly but a a bit higher in quality, just make sure you get a chiller (if you need one) that will handle the load that is put on it

 

[tegee]

Thank you very much for all your help.....I think you may be right. I am on the borderline for a 1/2hp. I ran some quick math using your equations and I came up with 3825 in lighting demands and 1330 in pump wattage demands. That totals ~5155 btu's; falling into the 1/2hp and/or 1/2 ton catagory. Well at least the good news is that nothing is wrong with the chiller and it has been professionally service, so I can safely see if someone can use it locally. Now I am off to spending some serious $$$ on a 1/2hp which is the bad news. Gosh, I hate this hobby sometimes.....lol.

Thanks again and I will post if something should change along the way. But your professional help is greatly appreciated......

 

[ihavtats29]

not a problem