An Aqua Logic 1/3 HP needs 600-1200 GPH. At 150 GPH your not taking enough heat out of the refrigerant. Gas pressures and temps inside the chiller are out of wack and the compressor is running too hot, leading to premature compressor failure. The Aqua Logic is 3/4" but you cant run to the other end of the house like that. A gallon in six seconds is too fast for 3/4". Let all the head come from the chiller, use bigger pipe too and from.
Chiller Plumbing Restriction
- Thread starter d2mini
- Start date
Ok what I should have said... at 150 GPH the refrigerant is not taking enough heat. So the refrigerant is too dense when it gets back to the compressor so the compressor over works and gets hotter than design. And you might get a percentage back as liquid. The compressor is supposed to pump gas. Too much liquid refrigerant could outright break it. Don't run it under flow for more than a few minutes.
jamie1981
New member
Didn't catch that but yea if the mag 12 uses 1 1/2" fittings and your restricting it down to 1/2" at one point I would say that is a big factor here.
d2mini
Premium Member
Ok, now you've got me freaked out!
LIQUID????? As in liquid that could get into my tank???
And yes, I have heard it run noisy sometimes. I thought it was just getting old.
The pump i'm using came with three different size fittings. I'm using the 3/4" fitting. It does have a 1" I can switch to.
When he says liquid, he is referring to the refrigerant which can become liquified under certain conditions. This isn't something that can get into your tank but when the gas becomes liquid, it can destroy the compressor.
No I mean the Freon, the refrigerant. Its all sealed up in there and cant get to the water(except it can when the titanium breaks, very rare, almost unheard of).The compressor pumps Freon gas to a higher pressure and this adds heat. Then it goes through the coil with a fan blowing on it, where it losses the heat and condenses into a liquid, still at high pressure. Then it goes through a expansion valve, that valve keeps higher pressure on the compressor/condenser side. And lower pressure on the evaporator side. The evaporator is the titanium part. When the Freon passes the expansion valve it gets cold, like a spray can would if you use the whole can at once. The heat from the aquarium water warms the Freon up some again at the evaporator. You moved heat from salt water to Freon. Now Freon gas goes back to the compressor to add more heat as it runs the pressure up. And the condenser coil with a fan blows out the heat from compression and the heat it took from the salt water.
The pressures and temperatures must be within design limits. These chillers are made for water in the 70-90 degree range. They have special chillers for cold water tanks. But any of them rely on certain temps. If you don't add enough heat to the Freon because of slow flow through the evap... the titanium thing, you could mess up the point where the gas turn back to liquid. And the compressor needs a substance it can compress. Like if you fill the piston on your car with water and then turn it over you'll blow the cylinder head off the engine. If your getting a percentage of liquid back to the compressor it will rattle. That stresses the compressor and makes it run hotter than it is supposed to. Too much liquid can kill it right away.
So everybody reading this make sure you always have good air flow at the condenser coil. Everybody look up the minimum water flow listed for the titanium evaporator coil. Going below minimum will wear out the compressor and maybe quick. You wont be able to go over max water flow without like a 1 HP pump or something crazy at 40PSI.
At 25% of min flow your probably making really cold water but not enough of it. Maybe somebody here could say better, but I been setting up for a delta of 8. If the tank is 80 I want chiller output at 72. Within flow specs of course. If you have a delta T of 16 your heat input to the DT may out run you. Seems like 1 gallon at 16 colder would be the same as 2 gallons 8 degrees colder. But it doesn't work like that for some reason. More flow though a chiller works better.
uncleof6
Active member
Phew.
But interesting.
Well, still have not go into duty cycle... I did a similar write up here like wolf's, and mentioned duty cycle, but killed it beacuse I got tired of typing, and went back to the pumps instead...
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d2mini
Premium Member
The chiller has a maximum 3/4" input/output barb fittings.
So if I change all the plumbing from 3/4" to 1", and change those chiller barbs from 1/2" to 3/4", that should give me a pretty good bump in flow, correct?
And then I'll still probably need a stronger pump, correct?
So if I change all the plumbing from 3/4" to 1", and change those chiller barbs from 1/2" to 3/4", that should give me a pretty good bump in flow, correct?
And then I'll still probably need a stronger pump, correct?
That will improve your flow but I still think that chiller is undersized and that pump is likely not going to cut it. Friction loss coupled with the elbows is still going to reduce the flow enough that I doubt you will even meet the minimum flow requirements. The larger lines will certainly improve the flow though. For your water volume, I think you should be targeting 600-800GPH and I'd be aiming closer to the higher end. As I said earlier, I'd divert some of your return pump flow. As I said, I don't think you would even notice the diversion.
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While I agree with much of what you said, I figured I would point out that freon hasn't been used in chillers in several years. Instead they are using R-134 or even R22 in some cases. Similar issues though. I don't think refrigerant turning to liquid is a real issue for him. Also, these chillers have thermal overload switches so if the compressor overheats, it will shut down. That said, the real issue with the gas becoming liquid if I am not mistaken (aside from a complete loss of cooling capability) is that the oil in the refrigerant separates from the refrigerant and won't lubricate the compressor properly causing it to fail prematurely.
d2mini
Premium Member
I used to do that but changed to a pump setup because when i originally plumbed the system, i didn't have a chiller yet and I plumbed it with a ball valve in the incorrect spot, so i couldn't get enough flow to the chiller that way either. After the return pump I had a T. That means i had three choices on where to put a ball valve to control the flow to the chiller. Before the T would have done nothing. After the T on the way back to the tank would have been best. But unfortunately I chose after the T on the way to the chiller. Most of the water took the path of least resistance and went back to the tank even though the ball valve heading to the chiller was wide open. So I suppose I could replumb that section and put the ball valve after the T on the way back to the tank, to force the water in the other direction to the chiller.
Here is my return pump plumbing. Only thing I would do differently is using gate valves instead of ball valves. This was taken before I dialed down the chiller loop but it gives you a good idea of how I have it plumbed. I mentioned earlier that I run Hammerhead gold for my return. This was the original Hammerhead. I still have to dial down the return to the tank because even with the reactor manifold and chiller loop, I've got a ridiculous amount of flow in my tank. With your pump being a pressure rated pump, you've got more than enough flow to run everything.
That couldn't be that difficult to fix. I swapped my sumps and all my pumps and associated plumbing while my system was fully stocked. Took some planning and a handful of hours but I kept my system full and didn't stress anything in the tank. I plugged the bulkheads from inside the tank where there were valves to stop flow. Some were slip bulkheads while others were threaded. I just made what ever plugs I needed and threaded or pushed them in. They stopped the water enough to get the new plumbing in. You should be able to get a valve in there easy enough??
I assume the unplumbed line on the left side of this picture is the old chiller loop? How do the return lines enter the tank? Can you plug those lines in the tank if you don't have a valve at the tank or can you break their siphon? A gate valve would only take minutes to add. Especially with the work being done in the garage.
d2mini
Premium Member
Ya, that's a really old pic but you got it.
I have a cheap ball valve sitting here I'll probably use for now and stick it right above the red chair rail on that vertical run of pipe. Will take just a few mins like you said. I'll be doing a redesign of my garage setup so it's just temporary.
The chiller loop returns and feeds the refugium, which then flows back into the sump.
I have a cheap ball valve sitting here I'll probably use for now and stick it right above the red chair rail on that vertical run of pipe. Will take just a few mins like you said. I'll be doing a redesign of my garage setup so it's just temporary.
The chiller loop returns and feeds the refugium, which then flows back into the sump.
Yep...Duty Cycle could be off if Slief is right and you need a 1/2 HP, depending on house temps. And oil separation is one of the big problems with slugging liquid. Also, I just used Freon as a general term that I think everybody would understand. I don't mean to imply I think he has R-12 in there. AND SLIEF.. stop posting porn pictures here. Every time I see that I get stuck..for I don't know how long looking at that. I loose track of time. Even the floor...
But back too... Velocity. I like 1-2 feet per second but some will say 3-5 FPS is OK. 600 GPH on 3/4" is 6 FPS and every 5' of pipe adds 1 foot of head. So your pump has to make 0.43 PSI just to over come that 5" of pipe. Plus elbows with this velocity really jacks it.
1" is 4 FPS and 16' for 1 ft of head
1.25" is 2.2 FPS with 62' adding 1 ft of head
1.5" at 600 GPH is 1.6 FPS and you have to go 143' to add 1 ft of head
I always wondered why chiller companies make the inlets so small. Maybe they want the turbulence inside there. I also wonder why it matters which is in, and out.
But back too... Velocity. I like 1-2 feet per second but some will say 3-5 FPS is OK. 600 GPH on 3/4" is 6 FPS and every 5' of pipe adds 1 foot of head. So your pump has to make 0.43 PSI just to over come that 5" of pipe. Plus elbows with this velocity really jacks it.
1" is 4 FPS and 16' for 1 ft of head
1.25" is 2.2 FPS with 62' adding 1 ft of head
1.5" at 600 GPH is 1.6 FPS and you have to go 143' to add 1 ft of head
I always wondered why chiller companies make the inlets so small. Maybe they want the turbulence inside there. I also wonder why it matters which is in, and out.
