Got a chiller - Where should i put the pump/return?

[busichio]

So I wasn't happy keeping my tank 80-82 so bought a Coralife 1/6 chiller on craigslist. It has an internal temp thermostat. I have run it for a week now and looking to find better solution.

Right now, I'm using the internal thermostat set at 78 because triggering my apex with the apex temp probe turns the chiller unit off, therefore resetting the control temp (changes back to 80 when the power comes back on). My pump runs 24/7 and my chiller is on the whole time, and only activates when the temp reaches 78.8 ish. It takes between 1 and 2 hours to drop to 77.

My pump is sitting next to the skimmer in the middle chamber and the return for the cooled water from the chiller is going into the section of the sump with the return pump. My thought process was that this will give a more accurate reading by not sending the chiller water back to where the pump is, and sending it through the tank first.

Is there a better way to do this? Here is my temp graph from the last week. I don't mind this setup because id rather minimize the amount of times the chiller turns on and off in a day. Am I cooling too fast by dropping the temp 2 degrees in 90 min? Next step may be moving my temp probe into the display tank instead of the sump to test true temp, not sump temp.

 

[nautical_nathaniel]

2 degrees dropped in 90 minutes shouldn't be bad at all, cold water currents can cool natural reefs much more over a span of minutes.

I don't think there is an exact place to put the return line but I've seen them go directly into the tank and nothing bad was happening in that system. I would say somewhere convenient for your setup but not right at your thermometer.

 

[Eddie Rogers]

Following, I need to setup a chiller as well

 

[busichio]

2 degrees dropped in 90 minutes shouldn't be bad at all, cold water currents can cool natural reefs much more over a span of minutes.

I don't think there is an exact place to put the return line but I've seen them go directly into the tank and nothing bad was happening in that system. I would say somewhere convenient for your setup but not right at your thermometer.

Thanks for the response. If the temp change isn't an issue, ill probably just keep it where it is. Does anyone have a coralife chiller and know how to set the default temp when the unit turns on? I cant seem to find it online but just reached out to support to see if there is a fix. I would love to be able to use the apex to control a max run time of the chiller to 30 min to minimize swings.

 

[mfinn]

When I used a chiller, the pump was sitting next to the return pump and the return from the chiller was in the display tank.

 

[jda]

Chiller return should go into the display. Final chamber -> chiller -> into the display. Make sure that you have good flow in your display and the inhabitants will never even notice.

There is nothing that you can do with your Apex with the chiller except to shut the outlet down if the tank temp drops... this is an "issue" with internally controlled chillers and people who want to use a controller.

 

[Tanggy]

Chiller return should go into the display. Final chamber -> chiller -> into the display. Make sure that you have good flow in your display and the inhabitants will never even notice.

There is nothing that you can do with your Apex with the chiller except to shut the outlet down if the tank temp drops... this is an "issue" with internally controlled chillers and people who want to use a controller.

Instead of buying another pump for the chiller, would it be possible to use the existing return pump connect it to the chiller then out to the DT return (providing the GPH of the return pump is in the range specify by the size of the chiller)? thanks.

 

[jda]

Yes. Make it as part of your return. It will slow down the flow a bit, but no big deal.

 

[Tanggy]

Awesome, save $$$ on not getting a new pump and space in the sump. Thanks.

 

[ca1ore]

Instead of buying another pump for the chiller, would it be possible to use the existing return pump connect it to the chiller then out to the DT return (providing the GPH of the return pump is in the range specify by the size of the chiller)? thanks.

I futzed around with a separate chiller feed pump because I did not want to lose flow by using the main return. Never was really happy with it that way, so I decided to plumb it into the main return after all. Prior to inserting the chiller flow was 1,35o, after 1,325. Should have done it that way from the start.

 

[Lylelovett]

I futzed around with a separate chiller feed pump because I did not want to lose flow by using the main return. Never was really happy with it that way, so I decided to plumb it into the main return after all. Prior to inserting the chiller flow was 1,35o, after 1,325. Should have done it that way from the start.

I'm trying to decide the same thing. If I use a separate pump I'll keep it out of the sump since I have more room out than in, so that's an option. But my return's range 300-2000gph is roughly the same as my chiller's 400-1900gph, so I don't have to worry about a mismatch. How do you like it plumbed in-line now that you've had it that way for a while?

Did you use Tee it off and use ball valves or does it run straight through? What was your specific layout, if I can ask?

 

[jda]

Straight through all of the output so that the water ends up in the tank. Temp probe should be in the tank too.

 

[ca1ore]

I think it depends on which chiller you are using. In my case, it's a trade winds 3/4 HP with the temperature probe in the heat exchange chamber. Pros and cons to that approach, but one consequence is that it does not like low flow. Ive found even the low end of recommended flow to be unsatisfactory because the unit tends to short cycle (though I can increase the setback on the Ranco to partly mitigate this). Long story short, putting it into the main return was the only way to get to the flow number, and since the chiller is native 1 1/2" PVC, the friction loss turned out to be quite minimal. So, main return line, but plumbed outside, so an extra run of 1 1/2" flex was required. I have them connected with inverted unions so that I can easily take the chiller out of the circuit when the weather cools. I probably could have done it with ball valves.