chiller not chilling the water properly

[ahochan]

Hi,

I recently installed a chiller in my 100 liter tank+sump setup. The chiller is rated for up to 360 liter, so it should be more than big enough.

Beside the fact that it is very noisy, I am getting very poor performance. It chills the water at about 0.1-0.2 degrees (centigrade) an hour, and does not seem to be able to chill the water below 26.5 degrees. Room temperature is about 28-30 degrees.

I run it off the sump return pump, which is rated at 40.5 liter / min. The manual for the chiller says to run it at 20-35 liter/min.

Could the water flow through the chiller be too high? Could anyone that has experience using chillers give some advice as to whether to run it on a high speed pump or a low speed pump.

 

[roka64]

I would run it as the manual says. The longer the water stays in it, the cooler it should run.

 

[tecwzrd]

If you can maintain 26.5C (79.7F) that temperature is fine as long as it doesn't fluctuate too greatly (=<3 degrees) in a 24 hour period.

Chillers work best with the proper flow rates it's designed for but I'm mostly confused why you are using such a powerful pump (2430 liters per hour/642 GPH) on a 100 liter/26.5 gal tank??

If you're happy with the pump/sump setup as it is now you could just T off the return to the chiller and the tank separately and control flow with a ball valve.

Do you have a fan blowing over the tank as well?

 

[ahochan]

If you can maintain 26.5C (79.7F) that temperature is fine as long as it doesn't fluctuate too greatly (=<3 degrees) in a 24 hour period.

I can maintain the temperature for now, but I am worried about what will happen in July and August when the _serious_ heat sets in.

Chillers work best with the proper flow rates it's designed for but I'm mostly confused why you are using such a powerful pump (2430 liters per hour/642 GPH) on a 100 liter/26.5 gal tank??

The pump is a Rio 1700. I'm using it simply because it was included in the tank+sump+stand set I bought. What would a suitable flow rate for sump return line be?

If you're happy with the pump/sump setup as it is now you could just T off the return to the chiller and the tank separately and control flow with a ball valve.

That's a good idea. Can I get a splitter that includes two ball valves, or will I need to get two or three separate units and plumb them together?

Do you have a fan blowing over the tank as well?

Nope. I've considered adding one, but I haven't found a quiet one yet... everything I add to my tank seems to double the noise level, and its starting to drive me crazy

 

[tecwzrd]

Your Rio 1700 does 325 GPH with a 4 ft head which is perfect flow rate for your sized tank/sump and within the 20-35 liter/min that the chiller can handle so no splitting is required.

What brand of chiller do you have and what HP is it?

Even a fan on a stand would work well and most of those are fairly quite.

 

[ahochan]

I forgot to check the list for lift height, sorry about the confusion
I'm still left with a chiller that won't perform as well as I hoped though.

The chiller is a Japanese domestic model:
(GXC-400: http://www.gex-fp.co.jp/fish/catalog/surmo/cool.html)
Cooling power: 580 kcal, rated for up to 350 liter in room temperatures up to 35 degrees.

What is a HP rating?

 

[tecwzrd]

HP meant horse power which most chillers are rated at i.e. 1/10, 1/4, ect.. After translating the page it doesn't appear to have a HP rating but is the largest model they make from what I've gathered and costs $435.84 USD so it looks pretty decent to me.

Considering what it costs, that you have the correct pump, and that you only have normal output lighting I'd return for either another model or a new model. This chiller should easily be able to cool your 100 litter tank and most likely defective.

Only other questions are how long have you had it, has it ever cooled your tank properly, and if older then 6 months have you cleaned the filters.

 

[ahochan]

Actually, I paid about 300 USD for it (online), chiller prices vary wildly here, even depending on which online shop you use.

I've only had it for about two weeks. The weather has cooled down a bit the last week, so its just idling now. The first week I ran it the weather was much warmer, with the room temperature rarely dropping below 28-30 degrees. Even though I tried to set it to 25 degrees, it didn't manage to go below about 26.5 degrees, and it used several hours to get there.

I'll try and contact the manufacturer directly, they seem to have a 1 year warranty. What kind of chilling speed should I reasonably expect? For instance, how many degrees can I expect it to cool per hour. As you said, the chiller should be more than capable of chilling my tank on paper, and I bought their biggest model with the hope that it would result in the compressor not kicking in so often. Also, I hope to upgrade my lightning to MH (currently PC btw., mistake in myinfo), which seems impossible with the current performance.

 

[Kurt_Nelson]

Only other thing I can think of if it's not defective, is if there's adequate airflow through the chiller. Do you have it in a place where it can get plenty of air? You don't have anything blocking the sides/front/back where the air goes through it, do you? If so, that will reduce the effeciency.

 

[tecwzrd]

Most chillers that size should be able to drop your 100 liter tank by .5-1 degrees (C) per hour.

 

[ahochan]

The front of the chiller (the air intake) is completely open, the back air exhaust is a bit closer to the wall than what is recommended in manual, so I guess I should try to move it a bit further out. I'll have to wait a few weeks for the next heat wave though

I contacted the manufacturer, and they seemed to agree that my setup was ok, and that it is under-performing. If it doesn't perform properly when placed further from the wall, I'll have it replaced.

Thanks for the help