How long is a chiller suppose to take to cycle?

[jetfixr]

I have a JBJ chiller I got second hand. I have never ran a chiller so I am not really sure what to expect of it. It is a 1/4 jbj on a 90g tank with about 30 gallons in the sump. It is a bit oversized so it should work great. I initially ran an Eheim 1260 with it but thought by upping the flow I might see a performance increase so I hooked it up to a mag 9. There is really no cooling difference between the 2. I am running 2, 175 watts MH's and 2, 110 VHO actinics. The canopy is open in the back with the MH's being about 10 to 12 inches off of the water, I have an 8 inch fan blowing on the tank and a 7inch fan blowing on the sump. Room temps are 75-80 degrees and it takes about 45min to cool 1.5 degrees. Is this normal? The cooling time seems a bit excessive to me. What should the temperature differential between the inlet and the outlet? I have it set to kick on at 79, and turn off again at 77.5.

[solitude127]

I have a 1/5 on my 90 with T'5 and depending on the ambient temp., mine can take up 1 1/2 to bring down to the temp. I have mine set to turn on @ 80 and off at 78. Durring the winter when the ambient temp is much much lower it'll only take about 45 min to pull down to 78.

[Jefe12234]

I have a 1/4HP CSL chiller on my 120 and I've never timed it, but I'd guess it takes close to an hour to drop the temp 2 degrees. The performance curve in the manual also shows a slow drop. I've also seen a 1/5HP PCI chiller that would only run for a few minutes at a time, but much more often. I'm not sure if that was a flowrate issue or what, but it's probably better for the chiller to run longer and less often.

[jetfixr]

Hey thanks for the input guys. Never having ran a chiller before, I didn't know if my chiller was working right. It looks like my run times aren't out of the norm. Much appreciated.

[BangkokMatt]

Sounds about right to me as well

[vader88]

I would think it is by design that the chillers take time to bring the temperature down. If you drop the temp to quick, that would be very bad for the LS

[DarG]

It all depends on heat load, ambient temp (which actually effects the BTU of the unit) , pull down and other things. As others have stated, it sounds very reasonable and I wouldnt worry.

[jackson5]

Sounds like it is working fine.

[jnb]

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