Pump Gurus needed

[Daimyo68]

OK pump guru’s, here’s one for ya.

System was installed several years ago during the home construction with the previous owner. He moved onto another maintenance guy, who installed another tank after the first one “popped”, and when they installed the new tank, they removed the chiller from the system. (Don’t ask why, I don’t know the answer).

The system runs 80-81 on an almost constant basis, deal with several issue caused by the temps, so I want to put a chiller back on the system. (I have already checked all sources for heat generation, etc etc).

Anyways, the original installer had the bright idea to run 1” pipes the way you see them in the diagram, outside to the chiller. Chiller outside, great idea, pipes ran the way they are…, in the walls… crack cocaine? Shrooms? It was during construction, they could have easily been run low in the walls…

The system has 2, Current DC return pumps, but will not push the head pressure that is present with the plumbing the original installer installed. Being I have several pumps laying around, I have tried Mag drives up to a 24, other AC and DC pumps and the latest attempt was with a Jebao DCP-18000 (I have this for moving SW from my mixing Tank).

I can get water to, and through the chiller, but it cannot make the push back up. There are no blockages as I can push water through each pipe without issue

FWIW: I believe there are a total of 10, 90’ elbows (just assuming since I cannot access any of the plumbing except the ends of the pipes where they terminate), 2 ball valves at the chiller (Just installed them where the pipes were capped outside the home).

My thought is that I am going to have to go with a Reeflo pump with the capability of overcoming an incredibly high head pressure.

Open to suggestions, I just don’t want to drop hundreds on a solution hoping it works.

 

[aaronpentz]

You only have a little bit of head pressure in that system. Having 2 downhill runs will cancel out the 2 uphill runs. Problem you're having is getting it started

This will not however remove the friction loss from the plumbing itself or the fittings. Once you got all the air purged out of the system you should be fine. Hard part is designing for that. Must always keep the ends under water to not allow any air to get back in.

Best is to use a appropriate pressure rated pump or change the plumbing. You can get creative by finding a way to suck the air out of the loop to get the plumbing filled with water to be able to use a smaller pump


Use the plumbing calculator to see what pump you would need for the correct flow rate through the chiller as that matters as well.

Sent from my SM-G955U using Tapatalk

 

[kharmaguru]

Is there any way to elevate the chiller? Another option is a second inline pump at the chiller.

 

[wtac]

Use a pressure rated pump like BlueLine/PanWorld/Iwaki (Japanese motor) to run the chiller.

They use a bit more power but I prefer the magnetically coupled driven impeller vs direct drive for high pressure applications with small diameter piping as not a great idea to reduce the output diameter unless at the end of the piping run.

Based on the chiller size, volume of the system, temperature "pull down" you desire, factoring in flow friction loss, etc, to determine the flow rate the chiller requires. from there, you can determine the pump model.

HTH

Also, water in the lines will make pushing it out to start difficult in the beginning.

 

[Sk8r]

I use an Iwaki to drive water about that distance upstairs, and it has NEVER failed except once slowed in efficiency when a tiny snail managed to fit itself into the nearly equally tiny notch in the metal impeller cylinder. It was one of those bizarre events, and it was cured very simply, just a few screws to get in, and a few screws tightened back to get it running. Alas, the snail was no longer functional. This pump has run since 2007 with no other problems. It's the Japanese motor ---attach your own plug to the wire.

 

[Daimyo68]

Thanks for all the replies.

I attacked it again today, with what aaronpentz mentioned about getting it started, as it was the same thought that was in my head, because it obviously worked at one point, I just needed to find a way to overcome the last bit of the plumbing and get it filled with water instead of air.

What I first did was to hook up pumps to both lines, pushing. I then, using on/off switches, pushed water back and forth alternating between the 2 pumps. Got some air out.

I then, reversed one pump (on the return side from the chiller into the sump, pulling from the line) I know, not intended to work that way) and got a few more bubbles, then nothing but micro bubbles here and there. I knew I got more air purged but it still wasn't moving volume through the plumbing thanks to the air pocket being at the top of the loop.

Well I decided to take a walk away for a bit.. came back 30 minutes later the sump was filled with micro bubbles, pushing intermittent instances of water. I sat and waited maybe 10 more minutes and it cleared right up, the last of the air had purged out, and I was getting full solid flow from the supply pump and the "suction" pump.

Turned off the "suction" pump and all is running fine now.

So in the end, I believe it was more patience taking authority over knowledge. I knew it had to work, I just needed to let physics takes its course.

I'm using a submersible DC pump, dialed down to roughly 60% power. The siphoning action of the plumbing when it drops down to the chiller as well as to the sump kept the flow pretty high, so no need to run it at 100%. If I was to estimate, I would say I am moving 500-600gph (chiller is rated at 480-1500gph)

Aquarium cooled down within a couple hours.

Thanks again all