chillers and pump size

[mikeross]

I have an ecoplus 1/2hp chiller that has yet to be set up yet. I have a spare 1200gph pump that I was planning to use along with the chiller but was also thinking of using it for top drip.

My question is... Should I use this 1200gph pump? The chiller has a max rating of 1200gph. I have read that its better to use a smaller pump so the water travels through the coils in the chiller slower.

Any truth to the above statement... anyone care to share their experience running different size pumps on their chillers.

thanks.

 

[pikes peak 69]

No personal experience yet, but using a smaller pump should cool the water more due to slower travel. You could still use the 1200 and put a bypass on the outlet. From the outlet of the pump use a wye and feed 1 leg to the chiller, the other leg of the wye you would dump back in to the res. If you put a valve on the 2nd leg nefore it dumps in the res, you can adjust the flow by opening or closing the valve.

Hope that makes sense,
pp69

 

[t7rln]

I was using a 1200gph with my 1/2hp chiller. I was not getting the low temps that I wanted. I switched to an 800gph that I had lying around and it seemed to improve my temps.

I must include that I made a few more changes at virtually the same time, which were to cover my res. with 1" foamboard (my res. is inside my grow room), and improve ventilation (my chiller is hidden in one of those garden hose boxes). My chiller is outdoors (piped into my grow room) and the other variable I can not account for are the outside temps variations, and air flow (wind).

I would guess that there is truth to the diff. size pump theory, but I did not isolate the change, so scientifically I cannot be definite with all of the variables.


There seems to be truth to the statement.

The "Y" set-up described in the previous post would give you a nice level of control of the H2O flow, and after playing with that set-up for a few days you should have clarity.

Remember to share your results with us if you learn more.

Thanks and good luck,

t7rln

P.S. Keep in mind that is takes hours to change the res. temp. reading at your chiller (like from 22.0C to 19.0C).

 

[JPLord01]

Cover up your tubs for one the black tubs will make the water hot. If your chiller is not cooling the water down where you want it. Put a big fan blowing in to the water this will help.
I have 6 tubs so that is 120 gl of water I have a 100 gl rez that I fill it up to 60 gl so that is a total of 180 gl of water. I have a 1/10hp chiller and my rez temp is 66degs
My rez is outside of my room.

 

[mikeross]

yeah my rez is outside my room as well but in the same room as my ballast. I have yet to set it up yet. I think I am going to buy a another 1200 for my top feed and run a 1200 for my chiller with a little tee off to control flow of the pump.

I will report back with my findings. Things should be up and running within the next 10 days.

 

[Giddeon]

I recently talked to a aquarium store tech (the guy who was in charge of all the tanks they had set up there) while buying a 1/2 hp JBJ chiller. His advice was to run the max pump rating that the chiller suggested, he said that "They have that rating to show what flow rate that the chiller works best at, its when you go above or below these points do the chillers start to decline in efficiency. Pumps lose flow depending many variables in the line so goinging with a pump that is at the max flow rating (100%) should put your actual flow rating through the chiller in about the upper 60-80% range of your chillers rating, which is about optimum for chilling."

Hope this makes sense the aquarium tech probably explained it better but that was the general idea

In the end I went with his advice and went with a 1800 GPH pump through my 1/2 hp chiller and have been very pleased with the results.

The test was on a 6 plant UC. My chiller is also very well ventilated.

 

[t7rln]

Chiller ventilation is very very very important.


t7rln

 

[socalsinner]

I have my chillers in a nice cool room and two fans pointing at the rear of them to circulate the air.

 

[mrdizzle]

I have mine back directly up to my outtake