Help, chiller not working right!!

[briandg]

Hi,
I was hoping someone could give me some advice on a used chiller I recently purchased. It was sold as a 1/3 hp Aqualogic, but in researching once I received it, I believe it is a Custom Sea Life chiller, but the compressor is still 1/3 hp. It is a drop in chiller I'm using for my 180 gal tank. I have the chiller sitting outside of my stand with the coil in the sump just before the baffles that lead to my return pump. I set it up the other day, and it seemed to take about an hour and a half to cool my tank 2 degrees. At first I thought it needed recharged, but when I removed it from the tank, I plugged it in just to see if it was chilling, and the coils started to ice up within a few seconds. So I am really confused as to the cause of the inefficiency. Does anyone have any suggestions as to the problem. I've never used a chiller, but I know that a 1/3 hp chiller should be able to cool my 180 with only vho's 2 degrees in less than and hour and a half. Any suggestions would be greatly appreciated.
Thanks

 

[scoobs]

Well I cant help much but I took industrial maintenance before I went into nursing and I can tell you the only way it would lose its refrigerant is if it had a leak. Other wish it should never need to be recharged.

 

[cmaxwell39]

How good of flow do you have going through your sump? If you do not have good enough flow it could take extra long to cool off you tank since the cooled water will take longer to mix with the whole tank enough to have an impact. It could also have a small leak and have lost enough refrigerant to make it slightly ineffecient, but not enough that it does not ice up when you pull it out of the water.

 

[briandg]

Thanks for the replies. I thought about the flow, but I have a thermometer in the sump and in the display, and the sump is staying relatively close to the the display in temp, so I don't think it's the flow. I'm wondering about a leak, I have a friend who owns a heating and air company, think i'll have him check it out.
Thanks

 

[farslayer]

Is the coil cold or not? If not, you need to have it checked for a leak and have some refrigerant put in.

 

[briandg]

Originally Posted by Farslayer
Is the coil cold or not? If not, you need to have it checked for a leak and have some refrigerant put in.
I didn't check it while it was in the tank, so possibly I could've had the tubing kinked a little but i don't think I did. When I took it out, I plugged it in and the coil started frosting up in about 5 to 10 seconds.

 

[farslayer]

Feel it and make sure it is very cold. If so, you don't have a leak, there's another issue somewhere.

 

[briandg]

It felt very cold out of water, but I will put it back in the sump and check it. I also have a friend with a heating and air company, I will have him check it for leaks also. Just curious, approximately how long should it take a 180 to drop 2 degrees running vho's in a house that's about 80 degrees?
Thanks

 

[farslayer]

You don't likely have a leak IMO, if something leaks refrigerant it will cease being cold, but since he's a friend and you can get some free work out of him I'm not sure how long it should take. Is your tank usually 80 degrees? If so, then lowering it 2 degrees should be easy. Is the coil completely submerged? Can you post a photo so I can see? I have an aqua logic 1/3 HP with a leak BTW

 

[briandg]

Originally Posted by Farslayer
I have an aqua logic 1/3 HP with a leak BTW
Man that sucks, I hear they are hard to fix when they have a leak, but I don't know. I don't suspect a leak, I had it fully submerged except for the about an inch because I didn't want the tubing getting submerged. My house actually will be between 82 and 83 degrees in the heat of the day, I have my chiller set to kick on at 82 and drop the temp to 80. I'm not trying to keep it too cool, just withing a reasonable range. I really probably don't even need it yet, but will be adding mh's in the future and want to make sure I have the chiller figured out before adding it. It just baffles me that it isn't chilling any faster, it's almost like running a lower hp chiller that can't keep up, but i've confirmed it's a 1/3 horsepower. Like I said, I'm not sure about the flow rate, I bought the tank used and was told the return pump I'm using is 600gph, but it doesn't have any writing left on it. But I would think if it was flow, the 40 gal sump would at least show a decrease in temp, and I'm not seeing a rapid change in there either, it's staying pretty consistent with the display.
Also, what size of tank are you running your chiller on, just curious.

 

[scsinet]

The test you did does not confirm the operation of the unit.
Drop in chillers have coils designed to be immersed in water. Water holds much more heat than air, so the coil will get cold in the open air much faster than if it were immersed in water, and therefore the coil getting cold in open air is no indication that it will remove "1/3hp worth of" heat from the water when immersed. 1/3HP is a few thousand BTU... enough to cool a small room, so you can see how the coil getting cool is no indication.
The only way to check it for it's refrigerant charge is to have a technician open the refrigerant lines and place a manifold set onto the suction and liquid refrigerant lines, and calculate the refrigerant charged based on a superheat charging chart.
In a small unit like a chiller, window AC unit, etc the refrigerant lines are sealed, so you need someone that can recover the refrigerant and install schrader valves on the lines so that a manfold set can be connected and refrigerant can be recharged.
Drop in chillers can easily spring leaks because the flexible hose used on them have connections which get weak easily. Having your AC friend look at it is probably the best course of action.

 

[briandg]

Thanks for the advice. Because your description was over my head, I will print out what you said and let my friend read it. Hopefully I can get this figured out.
Thanks,
Brian

 

[farslayer]

My tank is a 125. The instructions I got from aqua logic said to check the coil that way, but I'm resorting to a technician as well.

 

[farslayer]

Just an update, the technician just left and said my refrigerant was basically gone. The coolant has dye in it, so I'm picking up a cheap black light to look for leaks.

 

[cmaxwell39]

Did someone put dye in the refrigerant at some point in time. If not, then your coolant does not have dye in it and you will not be able to find a leak with a black light. If it does indeed have dye in it you might want to consider getting some UV enhancing glasses as well (most of the time the look like yellow safety glasses) as this will make the dye color really pop and be a whole lot easier to see.

 

[farslayer]

Yeah, their refrigerant comes with dye he said. I never heard of UV glasses, any idea where to get a pair, or about what they cost? They sound pretty schweet.

 

[cmaxwell39]

The pair that I have came with the little flashlight style UV blacklight that I use for work. Like I said they basically look like yellow safety glasses.
I bought my UV light in a HVAC supply house since that is what I do for work, and can say from using them that they really make a the dye stand out where if you just see the dye under a blacklight with the

[hr]
eye it is sometimes hard to see. HTH.

 

[farslayer]

Awesome, that does help. We've got a supply store near us, several actually, and I'm goin' shopping

 

[sjimmyh]

I am a MM senior chief submarine sailor in the navy. I run, work on, troubleshoot refer systems as part of my job. If you have a leak, like Far has been saying its unlikely, but it is possible to have a small one that is recently formed. It wouldn't take very long though and you would loose the charge and it wouldn't ice up anymore.
Your friend should have a freon "sniffer" handy and be able to tell you if it is leaking in a matter of seconds if you take it to him (its like a gieger counter for freon, it clicks or beeps when it senses it). The fact that it iced up tells me that you have at least most of the charge still and most likely you aren't getting enough heat transfer to properly cool your tank.
I really don't know what kind of flow rate you should have for your model. I work on large plants not small ones, and the technology of modern chillers is most likely more advanced than what I work on in the Navy. I have a chiller though (inline) and I was just careful to ensure I was in the flow rate specifications of the manufacturer. I would get my hands on that data if I were you and ensure I met them.

 

[briandg]

thanks for the replies. I am going to swap out my return pump for one I know the rating on. Right now I'm taking the word of the person I purchased the tank from of the flow rate of the pump because all the writing on it has worn off. I don't think however that it's flow. It seems to me that if the flow was too slow at least the sump would be cooling, but it's staying the same temp as the display. My friend is coming over on Saturday to test for a leak, and check to make sure it's fully charged. I'll give an update on what he finds, again thanks for all the replies. I don't think I can really diagnose the problem until my friend checks for leaks and if it's fully charged. One thing I forgot to mention is the person who owned it before me took it to an A/C place and had them replace part of the tubing with flexible tubing. I'm thinking either there is a leak where they did this or the a/c place didn't charge it correctly when they were finished changing out the hose. I hope this is the problem as it will be an easy fix.
Also, he came over the other night for a few minutes and we plugged it in without it being in water, only longer than when I did it. It did frost up some, but never got much colder, I could grab it without my hand getting too cold, so I don't think it's charged all the way or is leaking. He didn't bring his equipment with him, so I'm anxiously waiting for tomorrow .
Thanks,
Brian