Pump for glycol line chiller

[mattdee1]

I've built a "long draw" draft system to get beer from a keezer in the basement up to taps in my living room. I bought a trunk line from Micromatic and would like to cool the beer lines using a propylene glycol loop through the trunk line.

The attached diagram shows how it is set up. The glycol reservoir is in a separate freezer from the kegs, to enable me to get the glycol much colder than beer serving temp.

To move the glycol, I ordered a 800GPH submersible pond pump that had a claimed 10ft lifting ability. I knew this was marginal but I wanted to keep the pump power as low as possible to prevent excessive heating of the glycol reservoir. In retrospect, it was very dumb to pick a pump this small because it's not strong enough to push glycol through the whole loop. I tried priming the lines by pushing glycol through them under CO2 pressure and that worked for a while, but this pump is obviously not the right tool for this job so I want to get something else.

The glycol lines are 3/8", the total run length is about 15 feet, with a vertical lift of 8-9 feet.

Anybody have experience with a similar setup to recommend a good pump? How many watts can I get away with from a submersible pump in the glycol reservoir (5 gal)? I'm open to the idea of an external pump as well.

 

[mattdee1]

Bump

 

[mongoose33]

Here's the one SPIKE sells, which can be found elsewhere too:

https://spikebrewing.com/collections/conical-accessories/products/cooling-pump-1

I run mine through their temp control coil; the lines to the coil are 6 feet (times two, or 12 feet total), and the coil itself is probably....maybe 8 or 10 feet total? So call it something like 20+ feet of line.

I'm feeding that off a Penguin, and the lines have a head of about...oh, 3.5 feet or so. I'm also running them through a connector that restricts flow a little. Now, that's less than the 8-9 feet of head you're talking about, but it's really a pretty decent little pump.

*****

Different pump, but I use one to push cleaning solution through my keezer lines. What I found was that if I left it in a bucket on the floor, it had to overcome 3 feet of head in addition to the line resistance from 5 taps. It couldn't do it until I raised the bucket up on a chair to reduce the head. Remember, this isn't the SPIKE pump.

If your drawing is to scale and I understand it, it looks like you have your glycol reservoir in a separate freezer or refrigerator, a smaller one, sitting on the floor. You might try to raise that up on a cabinet, saw horses, whatever, to reduce the head on it. I don't know for sure that the SPIKE pump would work at 9 feet, but if you could pick the glycol reservoir up 4 or 5 feet, I would expect it to work.

You could try that with your existing pump and see if it makes a difference; if it does, then perhaps making it permanent and looking nice would be the next idea. You could even try this with a 5-gallon bucket of cold glycol solution, lifted up high enough to overcome most of that head. You'd know right away if it would work, and then you could begin the effort to make it permanent.

Just a thought....

 

[mattdee1]

@mongoose33 - thanks for the detailed reply.

Correct, the glycol reservoir is a bucket in a separate junker freezer that sits beside the keg refrigeration unit. I've already got the bucket sitting on a milk crate inside that freezer to lift it up a bit, but I suppose I could do a quick trial at a higher elevation and if that works then just put the entire freezer on some kind of riser. Unfortunately, it's not a mini fridge so it will be cumbersome.

That pump looks interesting, and they did mention that they tried 15 different ones before settling on that one, which is the type of knowledge I was looking for. Obviously that pump is not guaranteed to work in my setup, but it's something to look at.

Spike seems to be a re-seller that is packaging a pump that they found elsewhere into their system. Do you know if there is a generic name/supplier for that pump that I could find on, e.g. Amazon? I'm asking because I'm in Canada and every time I try to order stuff from a US supplier I end up getting hit with asinine shipping charges. If I can find it on Amazon.ca then I can get around that.

Thanks again, cheers

 

[Vale71]

I'm guessing they get it from China, like everything else...

https://www.aliexpress.com/item/328...chweb0_0,searchweb201602_3,searchweb201603_60

You need to find a pump that has a high pressure head with a low flow rate. Most small pumps are set up exactly the opposite, high flow rate and low pressure head.

 

[Tartan1]

I purchased 2 of these with speed control. Although a different end use I do use 3/8 tubing and the line lengths are about 8' ea in/out in my jacketed fermentor. With my setup it helps smooth out the on off cycles of the compressor, and better regulates temps in my fermentor by adjusting the flow rate to find the sweet spot.The added bonus I barely hear the pumps when running.
https://www.ebay.ca/itm/NEW-24VDC-M...591643?hash=item2ababd415b:g:UV0AAOSwy1ZdHEis

 

[mattdee1]

Thanks for the replies, all. I must say, when I was planning this project, I assumed that the glycol pump would be something I could figure out in 10 minutes of browsing Amazon, but that was not the case at all. It ended up being a very time-consuming exercise in sifting through all kinds of incomplete, confusing, and sometimes conflicting information and user reviews.

I ended up buying a Seaflo diaphragm pump, which I received last week and hooked up over the weekend. The spec sheet lists all kinds of uses for it but clearly the main reason for this pump's existence is to service the RV market - i.e., as a pump to provide water pressure to a large RV with a water tank. As such, it runs on 12VDC, so I also had to pick up a 120VAC - 12VDC power supply to run it.

It wasn't cheap, but so far I'm really happy with the purchase. This thing weighs about 5lbs and just feels solid as hell, has a nice heft to it, a nice big motor, integrated rubber mounts to damp out vibrations, and the pump head is exchangeable so if it wears out I can get a replacement. It's not submersible, so it sits outside of the freezer that chills the glycol reservoir. I like this setup because, unlike a submersible pump, it keeps the pump's waste heat out of the glycol reservoir. It's self-priming and capable of running dry, which makes it a breeze to get going once it's all plumbed up.

The pump's lift is not specified in its marketing materials for some reason, but the high-pressure / low-flow characteristic someone mentioned earlier is nicely met with this pump. It will provide up to 55psi pressure before it cuts out, but it flows only about 3 GPM.

Once I sorted out some line-kinking issues the pump was able to pressurize my glycol loop without breaking a sweat, and it's amazingly quiet - barely louder than the keg freezer itself. It's not intended to run continuously, but it shouldn't often have to run for more than a few minutes at a time because I've got it running on a STC-1000 temperature controller with the probe inserted in the trunk line. I still need to dial things in, but my plan is to find a sweet spot where the glycol freezer and pump are doing the lightest duty cycle possible such that foam and serving temp on first pours are acceptable. When I have guests over riding the taps, the cold beer continuously flowing through the insulated trunk line should almost take care of itself.

 

[crazyjake19]

Thanks for the replies, all. I must say, when I was planning this project, I assumed that the glycol pump would be something I could figure out in 10 minutes of browsing Amazon, but that was not the case at all. It ended up being a very time-consuming exercise in sifting through all kinds of incomplete, confusing, and sometimes conflicting information and user reviews.

I ended up buying a Seaflo diaphragm pump, which I received last week and hooked up over the weekend. The spec sheet lists all kinds of uses for it but clearly the main reason for this pump's existence is to service the RV market - i.e., as a pump to provide water pressure to a large RV with a water tank. As such, it runs on 12VDC, so I also had to pick up a 120VAC - 12VDC power supply to run it.

It wasn't cheap, but so far I'm really happy with the purchase. This thing weighs about 5lbs and just feels solid as hell, has a nice heft to it, a nice big motor, integrated rubber mounts to damp out vibrations, and the pump head is exchangeable so if it wears out I can get a replacement. It's not submersible, so it sits outside of the freezer that chills the glycol reservoir. I like this setup because, unlike a submersible pump, it keeps the pump's waste heat out of the glycol reservoir. It's self-priming and capable of running dry, which makes it a breeze to get going once it's all plumbed up.

The pump's lift is not specified in its marketing materials for some reason, but the high-pressure / low-flow characteristic someone mentioned earlier is nicely met with this pump. It will provide up to 55psi pressure before it cuts out, but it flows only about 3 GPM.

Once I sorted out some line-kinking issues the pump was able to pressurize my glycol loop without breaking a sweat, and it's amazingly quiet - barely louder than the keg freezer itself. It's not intended to run continuously, but it shouldn't often have to run for more than a few minutes at a time because I've got it running on a STC-1000 temperature controller with the probe inserted in the trunk line. I still need to dial things in, but my plan is to find a sweet spot where the glycol freezer and pump are doing the lightest duty cycle possible such that foam and serving temp on first pours are acceptable. When I have guests over riding the taps, the cold beer continuously flowing through the insulated trunk line should almost take care of itself.

Thanks for the update! I'm still working out the kinks (literally and figuratively) with my pump setup. I have a 120v pump that sits in the reservoir inside my keezer, but the pump being submerged eventually heats the glycol too much, so now I'm toying with ways to cycle the pump on and on with a timer or through the keezer temp controller by running only when the keezer is on. I like your idea of putting a temp probe inside the trunk line to run the glycol pump. I may have to change my setup to an external pump like the Seaflo, because my glycol reservoir is, at best, no lower in temp than my beer. And I already have several power supplies that would work with a 12v pump.

 

[mattdee1]

Thanks for the update! I'm still working out the kinks (literally and figuratively) with my pump setup. I have a 120v pump that sits in the reservoir inside my keezer, but the pump being submerged eventually heats the glycol too much, so now I'm toying with ways to cycle the pump on and on with a timer or through the keezer temp controller by running only when the keezer is on. I like your idea of putting a temp probe inside the trunk line to run the glycol pump. I may have to change my setup to an external pump like the Seaflo, because my glycol reservoir is, at best, no lower in temp than my beer. And I already have several power supplies that would work with a 12v pump.

I'm coming back here a bit late, but I've been busy and haven't been on here in a while.

I've made a few updates on my setup. I'm still very happy with the Seaflo pump, but I've changed some things around since my last message.

I mentioned before that I had the pump running on a temperature controller in the trunk line. I found a pretty bothersome flaw in this setup. What happened was I had the trunk temperature set lower than the system could achieve/maintain, so eventually through the night it got to a point where the pump was running continuously. When this happened, the pump constantly working on the fluid - for what I'm assuming was a few hours straight - had the effect of heating the glycol up, making the problem worse. When I checked it in the morning, the glycol reservoir's temperature was all the way up around 50F, and the pump was almost hot to the touch. Not good!

This made me realize I can't rely on the trunk line temperature being below a certain value to ensure that the pump gets regular breaks in operation. This opens up any number of possible failures. If the glycol freezer fails - for example - this would mean the pump would run non-stop until I checked on it.

So I decided I need to run the pump on a fixed duty cycle. I picked up this cool little timer circuit:

https://www.amazon.ca/gp/product/B074V863MR/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

It lets you dial in an "on time" and an "off time" independently. So, I set it up for roughly 30 seconds on, 15 minutes off. This means the pump is running only about 3% of the time. I still have the temperature controller probe in the trunk line, and the whole system will still shut off if the temperature in the trunk line falls below the set value. This is great for times when there are guests over and lots of pints are being pulled, keeping the trunk line fresh and cool on its own. Then, as soon as it sits for a while and warms up, the pump on/off cycle starts up again.

In your setup, I'd strongly recommend getting a non-submersible pump. If you're going to try to use the keezer itself to chill the coolant, you're going to need every efficiency you can get. Definitely make sure the coolant reservoir conducts heat well. I started with a plastic bucket, then moved to a spare keg, which helped me achieve a 4-5 degree improvement in steady state reservoir temperature.

 

[jamesC]

Bumping up an old thread.

Looking to setup a long draw too, the keezer is on the same level, but we're a distance away.
I calculated the length of the python is about 65ft, with the python going up to the ceiling 10ft high, across the false ceiling, then coming back down.

I'm wondering why you would require a high pressure head with low flow. I thought you would want a high pressure head and HIGH flow, so that it can draw more heat away by recirculating the cold glycol faster.

Anybody to enlighten?

Thank you in advance!

I'm guessing they get it from China, like everything else...

9.39US $ 21% OFF|200L/H DC 12V Water Pump Solar Power Hot Circulation Brushless Motor Aquarium Pond Submersible Pumps|Pumps| - AliExpress

You need to find a pump that has a high pressure head with a low flow rate. Most small pumps are set up exactly the opposite, high flow rate and low pressure head.

Thanks for the replies, all. I must say, when I was planning this project, I assumed that the glycol pump would be something I could figure out in 10 minutes of browsing Amazon, but that was not the case at all. It ended up being a very time-consuming exercise in sifting through all kinds of incomplete, confusing, and sometimes conflicting information and user reviews.

I ended up buying a Seaflo diaphragm pump, which I received last week and hooked up over the weekend. The spec sheet lists all kinds of uses for it but clearly the main reason for this pump's existence is to service the RV market - i.e., as a pump to provide water pressure to a large RV with a water tank. As such, it runs on 12VDC, so I also had to pick up a 120VAC - 12VDC power supply to run it.

It wasn't cheap, but so far I'm really happy with the purchase. This thing weighs about 5lbs and just feels solid as hell, has a nice heft to it, a nice big motor, integrated rubber mounts to damp out vibrations, and the pump head is exchangeable so if it wears out I can get a replacement. It's not submersible, so it sits outside of the freezer that chills the glycol reservoir. I like this setup because, unlike a submersible pump, it keeps the pump's waste heat out of the glycol reservoir. It's self-priming and capable of running dry, which makes it a breeze to get going once it's all plumbed up.

The pump's lift is not specified in its marketing materials for some reason, but the high-pressure / low-flow characteristic someone mentioned earlier is nicely met with this pump. It will provide up to 55psi pressure before it cuts out, but it flows only about 3 GPM.

Once I sorted out some line-kinking issues the pump was able to pressurize my glycol loop without breaking a sweat, and it's amazingly quiet - barely louder than the keg freezer itself. It's not intended to run continuously, but it shouldn't often have to run for more than a few minutes at a time because I've got it running on a STC-1000 temperature controller with the probe inserted in the trunk line. I still need to dial things in, but my plan is to find a sweet spot where the glycol freezer and pump are doing the lightest duty cycle possible such that foam and serving temp on first pours are acceptable. When I have guests over riding the taps, the cold beer continuously flowing through the insulated trunk line should almost take care of itself.