Grizzly 400 & ActiveAqua 1/4hp Chiller

laborde

What climate do you live in? You said it's outdoors but is it under a covered patio?

I'm in Austin, Texas. This week, highs have been around 90, lows around 70, and humidity has been relatively high for here. The whole rig is setup against the house and is slightly protected from rain by the overhang of the roof, but rain here rarely comes straight down, so I need to treat it as an "uncovered" situation. The whole setup is on the NE side of the house so it rarely gets direct sun.

Does the AA 1/2 model actually have larger ID tubing to increase flow? That would be interesting to know.

I assume the constriction happens inside the heat exchanger. I don't think the filter creates any noticeable back-pressure, but I'll make a point of measuring that, too. My plan is to fill a 5 gallon bucket and time it, to measure flow. If you have a better way, please share, but I think this is the simplest way I can come up with that doesn't involve special equipment.

One of my flow test goals is to see if the ozone venturi I have will change the flow much. I bought one that is designed for hydroponics rather than aerating the jets in a hot tub, so I suspect it will allow more water flow, and I might be able to put it in line, after the chiller, and keep the filter inline before the chiller, as it should be.

I'm disappointed at the low flow through the chiller, but I'm considering creating a "mode" switch that will meet my needs. If I install a switch that opens an sprinkler system irrigation valve to bypass the chiller, and simultaneously powers off the chiller, I can get that robust flow going for my plunge time. Having the water flowing over you is a great way to increase the cold exposure effects, and I was really looking forward to that until my chiller squelched the flow. I set up the water return the same way you did, opposite where I sit in the Grizzly, for that reason. Once I am building a control system, might just make it a big red button that starts a timer, bypasses the chiller with the irrigation valve, and powers off the chiller temporarily. Then the engineer in me kicks in and wants to ad app control, so you could create different profiles: Flow, no flow, and different times for the timer. I get a little carried away with these things, as you can see with my sauna controller app.

wintermute

I leave my pump running even when I'm in the plunge and I definitely feel it not letting me build up a heat barrier. Keep in mind that while you sit in the plunge the water temperature will start rising. This will cause my chiller to turn on but if you bypass the chiller it won't be able to offset the temp increase. This might not be an issue for you.

The smaller filter housings do restrict the flow quite a bit I believe. Here is a guy that did some testing: https://www.youtube.com/watch?v=UPiR30vWGaI
That's why I went with a whole house filter housing in order to not restrict it as much. But that could be pointless if the chiller is what's restricting it the most!

For measuring flow I filled a bucket to a known amount of water and timed it. I did it about 5 times and averaged it.

laborde

wintermute

I have a whole house filter as well. Since my setup is outdoors, I'm more likely to track junk into it.

So I added this little screen that catches the big stuff. It works remarkably well and just kind of stays in place even when I shut the pump off. I'm really wondering whether the 20nm filtration is overkill, now.

laborde

wintermute

In my case I think the 20 micron is definitely overkill. I'm planning on replacing it with a less restrictive filter in the future. I can easily get in pretty clean every time with little risk of tracking debris in. Plus, it really does restrict the flow in my case:

Without Filter: ~540 GPH or ~9 GPM
With 20 micron filter: ~372 GPH or ~6 GPM

laborde

wintermute

You know what is funny about that flow test video in the link above? There was no filter in the housing! The only flow limiting factor was the geometry of the housing. And then the guy modified the housing based on that test.

If you added the same filter to each housing, I bet you a dollar they were all about the same. The filter is the constraining factor in that case. The engineers who designed those filter housings surely knew that. They rightly had zero interest in optimizing the flow rate of the empty filter housing, since the filter itself is what sets the flow rate.

But I digress… Would you have any interest in a bypass, where you could hit a button and bypass the filter and chiller, and turn off the chiller so no damage would occur? Would you want this behavior to be on a timer? Or a manual toggle switch? I'm wondering if I'm alone in this, or if I should craft something that is mass producible.

wintermute

laborde That's a really good point about the filter being the limiting factor. I wanted a bigger housing so I could get filters with more surface area.

For me, I don't see a use case where I would want to bypass the filter and chiller.

wintermute

Did you use silicon or anything when you installed your bulkhead? I just tightened mine, and I have noticed that there is a very slow small leak coming from mine on the outside of the tub. I have tightened it so tight I'm almost afraid to tighten it anymore. I think I might have to reinstall it with some silicon caulking under the rubber gasket.

laborde

wintermute

I thought about it. Used to always use Permatex on engine gaskets so it seemed natural. But I shoved it in the hole I just drilled to see how it fit, and there it stayed. I did tighten it with some giant channel locks until the gasket bulged.

Since my setup is outside, I'm not sure if I would be able to detect a slow leak. There's just so much condensation.

wintermute

laborde Ha, can relate. Mine loosened up over time, i might have screwed it on a bit too tight, the cooler indented a little bit, enough that I can feel it. So I redid it with some silicon.

wintermute

Hey @laborde did you make progress on this? Did you per chance do flow rate testing with the chiller? I'm so interested in that test.

laborde

wintermute I've been waiting for some kind of final word on ozone destroying the Grizzly coolers. The guys who sell the modplunge are saying they have done testing equivalent to running ozone for 10 years or something equally outlandish. When I asked about their methodology, they just ran a Jed into the tub 24/7 for a month. These things don't scale in linear fashion, so I don't have any faith in that test. Meanwhile, a guy in some of the Facebook groups has posted pics of cooler damage he thinks is from ozone. It seems to happen above the water line.

This weekend, I'll probably go ahead and disassemble, do flow tests, and reassemble with the venturi in place, but I'll probably not run ozone until I have more data.

Meanwhile, I have been using grocery store peroxide. Where do you get the strong stuff? I should probably pick up the 35% like you're using.

wintermute

laborde I got the 35% H2O2 from http://bulkperoxide.com/ . There is also purehealthdiscounts.net and a few others I forgot. Thus far, I am perfectly content using just hydrogen peroxide at ₁₀₀ ppm. That probably has a lot to do with me only getting in the tub after a shower.

I haven't seen anyone post ozone damage to the grizzly yet. If you're talking about the picture of all the tiny holes in the plastic I believe it came like that from the factory. If you saw something else, drop a link please!

I'm looking forward to your flow tests!

laborde

Thanks. I need to do some math, but it might be cheaper to use grocery store peroxide in greater quantity, since it is so cheap.

I've seen a couple of "tiny hole" pics. One guy insists that they weren't there when he got it, that they appeared only above the water line, and only after 3 weeks of ozone use.

Another guy posted similar pics and said his came that way. He had tiny holes both inside and outside the cooler.

So far, I put about 8oz grocery store peroxide in a couple weeks ago, and my month old water is clear and there's no slime on the walls. Like you, I shower before I plunge. I'm adding an outdoor shower right next to the Grizzly, so I can come from my barrel sauna directly, without going inside.

laborde

Looks like the stuff from the grocery is cheaper, but not by much.

35% peroxide at $65/gallon

$65 / (128oz x 35%) = 1.45 per oz of pure peroxide

$0.64 16oz HEB 3% peroxide

$0.64/ (16oz x 3%) = $1.33 per oz of pure peroxide

wintermute

laborde Good call on the outdoor shower!

It doesn't make sense to me that ozone could cause those tiny holes. I would bet they were caused by a problem during manufacturing. I've seen many ozone degraded plastic and rubber components and usually it becomes brittle and starts cracking. Tiny hole person claimed it happened so fast, so time will tell in the next couple months after they start shipping with ozone generators.

Good call on doing the math for the H2O2. I currently added 1 oz of 35% H2O2 to get to 100ppm. That would be equivalent to ₁₁.7oz of 3% If I did the math right. So not much of an inconvenience.

Ecupirate

laborde not to butt into your conversation but I just bought a gallon of H202 from bulk peroxide. Use code welcomefam at checkout. It basically paid for my shipping cost.

laborde

I did some flow testing last weekend. I measured the time to fill a 5 gallon bucket. In each case I ran the components listed, but through a 3/4" hose, back into the Grizzly. I'd let it run until the flow was steady, then move the hose to flow into the bucket. I was a little surprised by the findings:

Pump + empty filter housing = 47s

Pump + filter = 47s

Pump + filter + chiller = 57s

(5gal/47s) x 3600s/hr = 383 gallons per hour

(5gal/57s) x 3600s/hr = 316 gallons per hour

So, why was I surprised?

1. Absent the chiller, I really expected the filter to be the main limiter of flow, but it was not. The freshly-rinsed month-old filter had literally no effect on the flow. I thought about removing/testing other components (like the Grizzly drain plug with hose adapter) but I had time constraints and moved on.

2. I thought adding the chiller reduced the flow much more than it really did. It only dropped ~20%.

3. This testing means to me that if I were to add ozone (unlikely at this point) I would add the venturi in parallel with the chiller rather than the filter. That would (a) bypass the tightest pinch point with a parallel path to create more suction in the venturi, and (b) increase the net flow. However, I had no slime or indications I need better sanitation. Grocery store peroxide every couple weeks seems to be more than enough in this cold, hermetically sealed system.

I also identified a leak (just like @wintermute) at the bulkhead connection. I wiped a little silicone on both sides of the gasket and took care of that.

surfdog08

laborde @wintermute so what size micron filter did you end up going with? Was 20 micron still too restrictive?

laborde

So, here's v0.2. I tidied up some of the plumbing, put a mat under the chiller, added some steps with storage inside, and an outdoor shower.

wintermute

laborde Thanks for doing some tests! What is interesting is that for me testing with my filter and chiller but no filter in the housing I get 8-9 GPM which is much higher than you get even without the chiller. But you also have much more friction from fittings than I do.

I like your setup, that is a really cool idea to have an outdoor shower.

When you say you added silicon to your bulkhead gasket, did you use sealant or grease?

etessier

laborde Nice looking setup. How do you drain this? … is the inlet above the water line?

surfdog08

laborde I see from your pics that you used the pre-manufactured grizzly drain as your outlet vs. drilling a new one (as Andrew Connor did in his DIY). Is there any benefit to doing it your way? I was thinking if I drilled a new outlet hole above then I could still use the grizzly drain to drain water from my cooler to outside since it will be inside my garage. How do you drain if you are using that?

laborde

wintermute I'm starting to appreciate that the plumbing is limiting flow quite a bit. I still think the chiller is the main limiter, though, and there's not much I'm willing to do about that. I could introduce a bypass valve to increase the net flow, but I'm not convinced it is worth the trouble.

I used silicon sealant on the gasket. Worked like a charm!