Chiller Plumbing Restriction

[d2mini]

I've got a mag 12 pushing water from my sump to my 1/3 hp JBJ chiller and back.
All in all, it's pushing about 6' vertical and 32' horizontal.
3/4" plumbing, mostly hard pvc with some flexible tubing.
45 degree elbows are used for a few 90 degree bends except for the elbows at the chiller.

Now, the problem is that with 6' of vertical head height, the specs of the mag 12 say it should be pushing over 700 gph. Yet I'm only getting about 150gph being returned to the sump. I had picked up the chiller used and for now I had to use 1/2" elbow fittings on it so I know that is a restriction, but would buying new 3/4" elbow fittings from JBJ increase the flow all that much?
This chiller requires around 450 gph of flow as a minimum and I'm no where near that.

 

[jamie1981]

So it's essentially a closed loop through the chiller. Could it be that you are getting a airlock within the flexible tubing or chiller? Are you getting any bubbles out of the return end? Since the chiller was used could there be some kind of blockage in it? Try to pour or better yet pump vinegar through it for a few hours to dissolve and calcium that might be built up in it. 150gph deff does not seem right.

 

[d2mini]

Hmmm... Good idea about the vinegar.
I have it returning through some loc-line at the sump so I can bend it slightly to have it pour in above or below the surface. Doesn't seem to make any difference. So I don't think it's air locked?

 

[jamie1981]

Your running over 40' of line 6' of vertical isn't much but if its going back down 6 feet you will get air that will also need to go back down 6 feet of pipe. Any air that is in the pipe will try to stay at the high points in the plumbing. I'm not saying that this is the issue but it could be. Once you get the air out of the line the flow will increase. One thing you can try to do this is take a shop vac and hold it on the return line in the sump coming from the chiller while the mag 12 is running this will pull/suck more air/water through the line essentially flushing any trapped air in the loop.
You will need some ready made saltwater on hand to do this as I doubt you want to dump the water collected in the shop vac back into your sump.

The same issues are seen in the old radiator type heaters that were used in homes. They would get air trapped inside them then you would get no flow through them which results in no heat. But once you bleed the air out of them they worked fine.

 

[slief]

How long is it taking for the chiller to drop your tank temps 1-2*?
I think your restriction is combination of the head pressure caused by height, the chiller, the elbows and other fittings. Any fittings you increase in size should improve flow by decreasing restrictions. Those 1/2" elbows, especially if they are barbed fittings can be fairly restricting in combination with the rest of the fittings.

I don't think this is a case of air trapped in the lines. Any trapped air would rise to the chiller tank and that should not decrease flow much if any. If it were trapped in the pump that would be a different story but air in the chiller should purge itself over time. The only downside to air in the chiller would be a decrease in contact time with the cooling coils which would decrease the chillers efficiency.

I wouldn't bother with vinegar through the chiller if your intent is to improve flow. I highly doubt you will see any improvement. I've run chillers for for the last 25 years and even after 15 years of constant use, there was no substantial build up of anything in the chiller tank that would reduce flow enough to worry about. If your desire is to clean the inside of the tank to improve it's efficiency, that's one thing but you're flow isn't being restricted much if any because of calcium buildup in the tank. That I can assure you of.

 

[slief]

I'm better that between the plumbing length, elbows, 45's, reducers, etc, your head pressure is closer if not in excess to 10' head pressure. I'd increase the plumbing line sizes and elbows anyplace you can. Every little bit will help. That said, I'm still curious how fast you're dropping temps through the chiller. If your seeing 1-2* in 30 minutes, your flow is likely higher than you think given your water volume and would be acceptable.

 

[d2mini]

I don't know how long it takes to drop temps but it can't keep the tank as low as I have it set. It's set to 79 and the tank still gets to 82. But without the chiller it would be higher. With 350 total gallons, 150 gph nothing.

 

[slief]

That chiller is to small IMO. Contrary to the JBK specs, I think you should be running a 1/2hp chiller with that kind of pull down requirement since you are needing several degrees. The jbj chillers have a relatively small tank and need higher flow for optimal efficiency compared to other chillers. I use 1/3hp chillers on systems half of your volume. You'd really need to increase the flow to around 600gph to get temps down to where you are targeting and even then, it will run 70% of the day if not more. This assuming your chiller is even working properly. The other alternative would be to look at what's heating your water and make some changes to reduce ambient temps. Given your tanks success, I doubt you want to go there but some pump changes may go a long way in reducing ambient temps. Those changes on my tank eliminated my dependency on my chiller entirely.

 

[d2mini]

Ya, if was to buy another one (maybe for next summer) it would be a 1/2hp.
And yes, i do need to increase flow! haha
It's the halides, and the fact that nearly half my water volume is in a 95+ degree garage in Houston.
With LEDs, the temps got up to 84 in the summer, no chiller. But now I obviously need one running MH and T5.

But yeah... i need to figure out how to increase the flow. Will start with some larger fittings. Maybe upsize where I have barb fittings to counteract that fact that their I.D. is less.

 

[slief]

Ya, if was to buy another one (maybe for next summer) it would be a 1/2hp.
And yes, i do need to increase flow! haha
It's the halides, and the fact that nearly half my water volume is in a 95+ degree garage in Houston.
With LEDs, the temps got up to 84 in the summer, no chiller. But now I obviously need one running MH and T5.

But yeah... i need to figure out how to increase the flow. Will start with some larger fittings. Maybe upsize where I have barb fittings to counteract that fact that their I.D. is less.

I don't think that pump is going to get you enough flow (for that chiller) regardless of the fittings. You might get enough flow to drop it another degree but given your plumbing lengths, fittings etc, there is still going to be several feet of head pressure if not more.

 

[slief]

I'd look at replacing that pump with pressure rated pump. If not sell that chiller & get a new one but even then, you're probably going to need a different pump like an Iwaki.

 

[d2mini]

Ya, you're probably right.
Spend money to save money, right?! lol Ugh. :blown:

 

[slief]

Ya, you're probably right.
Spend money to save money, right?! lol Ugh. :blown:

Yea but it's a double edge sword. The pressure pump could add to your ambient heat issues... I can't help but wonder how much if any your pumps are contributing to your heat issues. Granted your garage certainly plays a big role along with the lights.

 

[d2mini]

I have the mag 12 running the skimmer. That's actually what I switched over today and used on the chiller. Normally i'm running a Speedwave 1320 DC pump on the chiller that's netting me the same flow. I just wanted to try the Mag to see if there was any diff.

So other than those two, just my main system pump which is a Reeflo Baracuda Gold.

 

[slief]

Reeflo is a cool running pump.. Ever think about an AC in the garage? Probably more costly than a 1/2hp chiller when it comes to power usage though. Your still going to need a better pump and address your plumbing to make it work efficiently. I run my chiller 50' away in my garage. It's plumbed through 1" flex PVC which is run 18" under ground. There is about a 100' loop in total. I don't need my chiller though since raising my temps.

 

[d2mini]

Ok, good... i'm taking notes since there will be major changes coming end of this year.
Right now I'm looking for easy temporary solutions so I'll start with the larger fittings and see if that gets me anything.
What pump are you running on your chiller?
And are you running it inline (all water flowing through the chiller and then back to the tank) or are you doing it like me where it's a loop from/back to the sump?

 

[uncleof6]

I've got a mag 12 pushing water from my sump to my 1/3 hp JBJ chiller and back.
All in all, it's pushing about 6' vertical and 32' horizontal.
3/4" plumbing, mostly hard pvc with some flexible tubing.
45 degree elbows are used for a few 90 degree bends except for the elbows at the chiller.

Now, the problem is that with 6' of vertical head height, the specs of the mag 12 say it should be pushing over 700 gph. Yet I'm only getting about 150gph being returned to the sump. I had picked up the chiller used and for now I had to use 1/2" elbow fittings on it so I know that is a restriction, but would buying new 3/4" elbow fittings from JBJ increase the flow all that much?
This chiller requires around 450 gph of flow as a minimum and I'm no where near that.

The mag 12 requires the use of 1.5" outlet plumbing to get any flow out of it in the first place. The flow curve says one thing, but the friction losses say something different. It is not surprising that you are only getting 150gph out of that pump. The mag drive pumps are the last pumps I would use to run a chiller, if not for the lousy design and decpetive outlet size (covered in the instructions,) then for the heat they generate, adding to the load on the chiller.

You are spending the money to run a chiller, which I vigorously support the use of (to pull water temps down to a more reasonable temp like 75°F,) you should spend the money on a decent pump to run it. A DC pump would be preferable (less heat just for one reason.) Playing with the plumbing using the mag 12 isn't going to accomplish much.

 

[d2mini]

Chiller Plumbing Restriction

Uncle, see my previous post. I actually am using a dc pump. I was just testing out the mag 12. But I get basically the same result with both. Which dc pump would you recommend I try? Thanks!

 

[slief]

Uncle, see my previous post. I actually am using a dc pump. I was just testing out the mag 12. But I get basically the same result with both. Which dc pump would you recommend I try? Thanks!

Most DC pumps don't handle head pressure much better than the Mag. In fact, I think that Speedwave has a lower head pressure rating than the MagDrive.

At present, my chiller is T'd off my Reeflo Hammerhead return pump. I'm feeding it with around 700-900GPH. It returns back to my sump. Prior to that before my sump overhaul, I was feeding it with an Iwaki MD100RLT that would return through my previous Beckett Skimmer. At one point many years ago, I was feeding it with a Little Giant 4MD. Having said that, my chiller has not turned on in 3 over years since bumping my max temp to 82.

For your setup, I'd "T" into your Reeflo return pump or run it off your manifold using that pump. You'd eliminate a pump, save power and reduce a tiny bit of heat transfer. Put a gate valve after the T on the chiller side and another on the tank side so you can balance and create just enough back pressure for the chiller loop without sacrificing much if any flow to the tank. That pump is a beast and probably has several hundred gallons an hour available just because of back pressure. As such, I doubt you would even notice the diversion.

Also, adding some serious ventilation and airflow to your light setup/canopy if you haven't already done so will help reduce the heat transfer from the halides and T5's. My lighting is completely enclosed in a soffit above the tank. I've got a high CFM 10" industrial Rotron fan that ducts air from the the soffit to outside the house. When I was running halides, it kept the halides fixtures cool to the touch and eliminated most if not all of the heat transfer. My soffit did and still does stay at house temps.

You absolutely need a new chiller though. Your ambient temp is too high for the 1/3 in my opinion. That chiller will be working non stop and will likely run 14 or more hours a day to keep it at 78* That kind of duty isn't good!

 

[uncleof6]

Uncle, see my previous post. I actually am using a dc pump. I was just testing out the mag 12. But I get basically the same result with both. Which dc pump would you recommend I try? Thanks!

What size is the outlet? If it is 1", running it through 3/4" is going to choke it out as well. You mentioned 1/2" I believe, that is worse.

What I stated about the mag drive is very valid, and supported by Danner. It is not about comparing flow charts. (Though they don't make it very obvious.)

I am running several chillers here, and I generally use small pumps with them. I have a DC 3000 on one of them, and don't have flow issues, that I am aware of. I have not put a flow meter on it so... but I turned it down a bit...several notches. I run all the chillers on loops to and from the sump. I use the return pump for returning water to the tank. I run large pumps, but I don't run them larger than I need to, for the sake of multitasking them.