Chiller Question, again!

[rz1a]

ok so im going to do the cleaning of the chiller anyways, but i was just reading on RC where some guy says that he suspects that the person who isnt running alot of flow through his chiller is causing the long cycle to cool down water

does it cool it down that fast?

lets say min. flow is 600 and max is 1,000. i bought a 700gph pump, mag 7, so that would a little bit above minimum.

if i were to hook up a mag drive 9.5, which is 950gph and throttle it back, would this work out better?

[rz1a]

". . .Depending on how you have things plumbed and whether or not you have a pressure rated pump, there is a good chance you are not putting enough flow through that chiller. 60-75 minutes to cycle to your desired temp is quite long. A long cycle time is a good sign that you're not getting enough flow through your chiller. I have a similar sized tank [90 gallon tank] with a 1/4HP chiller and i'm running almost 700 wtatts of lighting over it and my chiller only cycles for about 15-20 minutes at a time to drop 1 degree."

[CoryDude]

How is your chiller plumbed? If it's tied into the return line to your tank, then you've got aout 3-4' of head pressure on the pump. Specs for that pump show the pump producing about 480-500gph at that pressure. A 9.5 would give you 800-850gph. Your chiller recommends 600-1000gph, so it may help to upgrade the pump.

Plus, you have a 75G right? The tank will benefit from the increased circulation.

[rz1a]

well, the mag 7 was plumbed straight to the chiller. i changed it over to a mag 9.5 and it looks like it solved the problem. went from 92 to 75 in 15 minutes for a 5 gallon bucket. before, it cycled for a long time just to cool down the water in a 10g container, and i mean a long time.

right now im cleaning the coils out with vinegar and water. hopefully that will help out

[CoryDude]

Cool. Glad it worked for you.

[rz1a]

it didnt work! plumbed it to the aquarium and it didnt cool below 78!

:rofl:

[CoryDude]

Aw the joys of reef keeping!

Just to verify, you're setting the thermostat on the unit for below 78, ie 72, and it won't go below 78? And you've verified this w/a separate thermometer?

Does that model come w/a built in heater? If so, maybe a temp control problem?

If you've checked those things and if the cleaning doesn't help either, then I'd maybe try and get hold of the unit's product support. If you have correct h2o flow, clean coils w/fresh air flow, and a clean contact chamber, then I don't see much else you can do.

[Bill S]

Where is your temperature sensor? If it's built into the chiller, sometimes the tip of the sensor can touch the outside of the temperature "well", which cools down very fast. I had that problem on mine, and relocated it to the tank.

[rz1a]

i had bought this chiller used from a member at ARC. i contacted him earlier this week and we tried to troubleshoot since he said on his 90g it was cooling down with no problem. on my 75g it just cant do it.

in a 5g bucket it cooled to 75 degrees, so i figured since it was working and it was the pump, that i could just plumb it with the new pump and it should work; well it didnt. it just doesnt want to cool below 78 and it has a hard time getting to 78 to start with.

the last thing i was thinking of doing was what a local member here said to do, which is to take it someone who works on Air conditioners to verify there's no leak and to make sure its full of coolant. he doesnt think that a 2 year old chiller would need coolant, but if its leaking then yes. he said its possible that there may be enough coolant to cool down 78 but not to cool any lower

[rz1a]

oh and theres no built in heater. it has a plug on the side where you can connect one and have it turn on, but i dont use a heater

im not sure where the sensor is located on this, but ive compared it to the thermometer and its pretty close to the chiller reading

it has a setting that is "d" to control when the chiller turns on, like a 2 degree difference minimum or up to 4 degrees

the other setting is called PD, which i dont know what it is. i askedthe original owner and he said he didnt know. its set on 00, but i can move it up or down to whatever i want. When I move it down to -02 the reading on the chiller changes instantly almost. So if its 78, and i put PD -02 it moves to 76

[CoryDude]

Just look for repair guys who work on window AC units and refrigerators. I'd try to find someone who'll let you bring the unit in so you won't have to pay a service charge for them coming out.

[rz1a]

yup thats what i was told to do by my friend. to take it out to the company insead of them coming to me. hopefully i can fix it and they can understand what it does

[rz1a]

something is going on. i must be doing something wrong, i just have no idea what..

so i have in my posession an Aqualogic DS-2 1/5 hp chiller; used, but in working condition. i'm having the same exact problem.. i was using a mag 7 but put back the mag 9.5 and throttled the pump back.

Pump now is hooked directly to the chiller, like before, only now its connected to a bulkhead going back to the tank so i save on the electricity bills

i just dont know, i guess i wasnt meant to be using chillers??

[Bill S]

Ruben,

If you can, diagram out the flow on the plumbing for your chiller. Even if it's just written. Along with plumbing pipe sizes too. My guess is that you don't have enough flow. Even with a mag 9.5, if you have ANY head, and/or any restrictions, you probably don't have enough flow.

[CoryDude]

Another thing you can do to test flow is to get a stopwatch and see how long it takes to fill a 1 gallon jug. You should get a gallon in at least 6 seconds in order to meet the minimum 600gph your unit needs. But, you'll most likely want the gallon jug to fill in 4-5 secs in order to achieve 720-750gph. Don't disconnect the unit like before. Actually measure the aquarium water coming out of the chiller.

[rz1a]

im going to start all over with the pacific coast cl-650 and let you guys know what happens. i went back to the 650 because it remembers my settings and it doesnt give me a hard time when i want to set it up. right now, night time, its staying at the set temp which is 78, i had brought it down to 77 but didnt look at the time to see how long it took. i figured it would be easier to add the 1/4 hp and use the 950gph pump since the MAX flow is 1,000 gph

the tubing is 3/4" and it connects from the pump to the chiller then to the tank for a return. i used to have the pump for the chiller only and it didnt work well back then either.

red is out from the tank where the overflowbox is, its a reef ready 75 so sorry if everything doesnt match up. the tube goes through a sock filter then to the 1st compartment where the skimmer is, then theres baffles then theres my return pump which is plumbed straight to the chiller, then after the chiller it goes back to the bulkhead and water is returned. the black tube is connected to the pump and the blue line is back to the tank

http://img.photobucket.com/albums/v603/rubensaurus/Untitled.jpg

[rz1a]

forgot to add that the sump is a 20g tall

[rz1a]

Chiller is set to cool down to 78 degrees with a 2 degree cooling degree difference for now, i'll turn it to 3 degrees later.

7:24am chiller comes on
7:37am chiller turns off
7:40am reading shows 79 degrees on the chiller

13 minutes runtime

this kind of reminds me of the neptune aquacontrollers where you have to set it at 78.0 for it to stop. if you set it at 78 the chiller maybe at 78, but probably in the high 78s so temp goes up faster to 79. so far its my only complaint with the chillers

im going to find out how long it takes once it gets hotter like around 12pm

[rz1a]

9:00am chiller is on
9:24am chiller is off

it already jumped from 13 minutes to 24 minutes and the lights are not even yet. im going to start the lights on at 9:26

[Bill S]

Ruben,

Here's what I would do. Plumb your mag 7 from your sump to your tank return. Then plumb your mag 9.5 from your sump, to the chiller, and back to the sump. Then MEASURE your output back to the sump (how much time it takes to fill a 5 gallon bucket). Your short cycling is likely one of 2 things: not enough flow, or a poorly placed sensor.

[rz1a]

The sensor for the 650 is built in. I had it plumbed like you said in the past and it wasn't working out too well. I think it was worse than this time.

Plumbed it this way to save on the electric bill since the mags eat up a lot of electricity

[Bill S]

OK, so how much flow are you getting from your return, at tank level?

[rz1a]

how do i connect a hose to the return line then to a bucket to find out how much water is coming out?

would it be safe to assume that the water draining from the tank is the same as the water being put into the tank?

i was using a head loss calc and it figures about 611 gph, and thats if i have 3 elbows, 4 feet of tubing that thats horizontal and 4 feet upwards

[Bill S]

You need to disconnect your return hose, and then put a 5 gallon bucket up at the same level as your return. Then time how long it takes to fill the bucket.