Flow rate for Chillers?

[flyingarmy]

I am about to hook up my 1/10 chiller and was wondering what the correct flow rate throught the chiller would be? During the Power Buy it was mentioned that a MAG 5 would be fine but that gives a good idea but not a min and max flow rate. What does everyone else use on their chillers? Thanks in advance!

 

[chemically_balanced]

I've got the a Current USA 1/10 chiller and I'm running a MAG5. Seems to work really well and just barely fit in the back side of the 30g All-In-One tank I have it on.

 

[cameron]

Slow is better. The more contact time a chiller has with the water column the more it will cool it. I would say a Mag5 on a 1/4hp is about right.

 

[burdundi]

Simon warned me that you don't want to go too slow on a chiller otherwise the heat exchanger will freeze and crack. On my 1/4 it recommends 10-12 gpm. I needed a mag 9.5 since I had about 10 feet of horizontal plumbing.
I used the head loss calc on reef central to figure out what I needed:

http://www.reefcentral.com/calc/hlc2.php">http://www.reefcentral.com/calc/hlc2.php</a>

When I had a 1/10 chiller, I used a Mag 5 without a problem.

my 2 cents...

Andy

 

[wbholwell]

Shouldn't there be a temp sensor on the heat exchanger so that it won't</em> freeze and burst? What happens if your supply pump fails?

 

[burdundi]

wbholwell;43175 wrote: Shouldn't there be a temp sensor on the heat exchanger so that it won't</em> freeze and burst? What happens if your supply pump fails?

I am not sure, but I would think that the water (not moving) would chill quickly and trigger the thermostat to cut off the chiller.

Now, if the water was warm and still moving, but very slow, I can imagine the heat exchanger staying on and freezing. For this to occur, it would probably have to be a large tank volume or a heater stuck on to perpetuate the warm water long enough.

Again, I do not fully understand chillers, so hopefully someone can jump in here with more knowledge.

-Andy

 

[cameron]

burdundi;43174 wrote: Simon warned me that you don't want to go too slow on a chiller otherwise the heat exchanger will freeze and crack. On my 1/4 it recommends 10-12 gpm. I needed a mag 9.5 since I had about 10 feet of horizontal plumbing.
I used the head loss calc on reef central to figure out what I needed:

http://www.reefcentral.com/calc/hlc2.php">http://www.reefcentral.com/calc/hlc2.php</a>

When I had a 1/10 chiller, I used a Mag 5 without a problem.
[/QUOTE]This seems unlikely on a modern chiller. Most chillers are plumbed into a closed loop so there is no virtually no head loss. A mag 5 should pump roughly 500gph or about 8gpm. I can see you moving up to a mag 7 for a recommended spec, but a 9 seems high.

 

[burdundi]

Cameron,

I have about 10 feet of horizontal pipe and 2 feet of vertical for my chiller. There has to be some head loss even though I do realize that it is very little due to only 2 vertical feet.

I did the calculations on RC with 10 horizontal, 2 vertical and .75 diameter pipe.

I got:

Total losses are 6 feet of head pressure, or 2.59 PSI. with a flow rate of 709 GPH

That's about 11.8 gpm for my chiller.

If I stepped down to a mag 7, I got:

Total losses are 3.98 feet of head pressure, or 1.72 PSI. with a flow rate of 480 GPH or 8 GPM.

That's why I went with the mag 9. I'd love to step it down to the mag 7 just to save a few kwh, but 8 gpm just seems to low on a 1/4hp.

Let me know what you think.

-Andy

 

[cameron]

If you go uphill and you have no downhill, then yes. However most chiller installations I have seen have as much down as up. Any down negates any up. Also keep in mind the bigger the pump, the more heat in the water thus the more the chiller has to work.

 

[flyingarmy]

So how did everyone plumb their chillers? In their sump or to their main tank. I am going to use an external pump, either a Iwaki or Little Giant both around 340-570GPH @ 1ft. Just wondering the best place to place the bulkheads in the sump? If you have any pictures that would be greatly appreciated!

 

[ouling]

My 1/6 chiller is run directly through my display tank at 300GPH then into my skimmer in the sump using a 1/4'' line, so there is no pumps needed (saves energy and heat). Works very well for me, if you need more flow you can always get a bigger line.
I believe in saving energy to reduce heat, and since the water is being siphoned down the tank to the sump, it'll help cool things a bit too.

 

[cameron]

Mine is more of a temp setup, but I run mine from a Mag5 into the chiller, into a canister filter (pump removed used for Carbon, GFO and Purigen) then into the UV. After the UV goes right back into the sump. Eventually, I am going to run mine T'd off the main return pump so I only have one pump to worry about.