Our 375 Gallon project

[Ken Sellick]

Excellent layout work. its nice to see someone take there time and plan things out. What is your electrical layout like?

[Hockeyben51]

THIS IS INSANE!!! I love how you are setting up and it leads me to ask what fish are going in there?

[JustOneMoreTank]

Hey LittleMax(Ben)...
I have a Black Rubber piece of tube as well. I had to use it when I modded my ASM G4 skimmer to be a Recirc style. It connects the intake from the skimmers body into the Sedra needlewheel pump. This will all be in the sump so I am not worried about the connection at all. I would question its watertightness if it was in an external situation.

[LittleBlueGT]

Originally posted by JustOneMoreTank
Hey LittleMax(Ben)...
I have a Black Rubber piece of tube as well. I had to use it when I modded my ASM G4 skimmer to be a Recirc style. It connects the intake from the skimmers body into the Sedra needlewheel pump. This will all be in the sump so I am not worried about the connection at all. I would question its watertightness if it was in an external situation.

How thick is the rubber? Mine was 1/4 thick, and it came with two heavy duty clamps.

[Marc Daniels]

I have a question regarding your foam background. I tried doing a foam background on a 72g bow-front. The foam was so bouyant that once I added water it pulled itself away fromn the back wall within a few days. How are you combating this problem?

Great tank. I'm planning to get a 300g from Miracle in Glass in the next year.

[JustOneMoreTank]

LittleMax... I just measured it. Was difficult to tell for sure but it seems much thinner than 1/4". I think that it is only 1/8" thick. Mine also did come with two heavy duty stainless steel clamps as well (which are not being used as this will be submerged). The diameter (as you can see in the picture) is just perfect to be stretched very very tightly over the outside of the standard 1" PVC elbow. The fit over the outside of the stock ASM Venturi pipe was not as perfect. It was not as tight. That is why I have the two Electrical ties (also know as Zip or Plastic ties).
I am not sure if the connection would be trusted 100% in an external configuration to be drip-free but mine will be located insump.
The rubber is very soft and pliable.
Hope this info helps you and anyone else.

[sidewinder770]

Sorry for the lack of replies. we've actually been hard at work on the tank this weekend and have gotten a lot accomplished. We got all the tanks finished for the sump cabinet, got almost all of the plumbing done in the sump cabinet and were able to wet test everything last night. Still have more to do but this was a big jump forward and it's looking more and more complete everyday. I'll try and take some more pics of it tonight.

Ken Sellick- My electrical is the next job to finish. I've run a seperate 60A dedicated circuit to a panel mounted on the end of the sump cabinet. Inside I have 4 15A breakers and 2 20A breakers. The 20A's are for the chiller tube and the A/C unit. The 15A are for everything else with a circuit going to the tank for lighting, and 3 circuits in the sump cabinet. I'll try to post some pics of that if you like.

Hockeyben51- Fish? Is that what this is for? I've been working on the setup for so long I almost forget about what's going in it. I don't have a speciic list of what going in it or anything but there will be a lot of SPS, some LPS and definately quite a few fish- just not sure what yet.

Marc Daniels- That's strange- what kind of foam were you using? We used the black 'handi-foam' for ponds and have not had any problem with it coming off. We've only used this on acyrlic tanks- is your glass? If it is I'm not going to be of much help as I've never tried but I would think it would hold just fine on glass.

[Marc Daniels]

Scott-

Yes, the bowfront was glass. I was using the Great Stuff foam. Great Stuff is made for insulating, and it may be a different consistency than what you're using.

Marc

[sidewinder770]

Marc Daniels- I've never tried the great stuff so I wouldn't be of much help there. I've heard of other people using it and I don't remember them having a problem with it but I'm not sure.

Well, last night was pretty exciting- we got the DIY/homemade/pieced together/not sure if it would even work chiller tube running. We still have to have the HVAC guy out to double check my temps and pressure and still need to adjust the flow correctly for superheat but so far it looks like it works like a champ and only draws about 5-6amps while it's running. Here are the test results which we hope will get better once it is really dialed in but we're pretty happy already-

Aproximate water volume in sump room tanks at time of test- 180 gallons

Ambient garage air temp at start of test- 100
Ambient garage air temp at end of test- 93

Water temp at beginning of test- 91.1
1/2 hour temp.....86.0
1 hour temp....... .82.6
1.5 hour temp......80.1
2 hour temp.........77.2
2.5 hour temp......74.6
3 hour temp.........72.3
3.5 hour temp......70.1
4 hour temp.........68.1
I turned the chiller off at 4 hours and 10 minutes at which time the water temp was 67.6.

We're pretty happy with that and hopefully it will get better once it is dialed in correctly.

Anyway- still have lots of work to do in the sump cabinet but here's a few updated pics while I was testing the chiller last night-

[NOLACLS]

Now that IS one hell of a setup man....bravo

All you people with equipment rooms really make me sick I have to stuff my stand....

[Fliger]

Wow Scott, that looks great. But one question, how did you get your ambiant garage temp down to 93? That must have been at 3:00 a.m. ;-)

[AcroSteve]

Re: Chiller

I have the same type of DIY chiller on my system and have a permanant temp reading at the suction side of the compressor. Meaning, I did not remove it after setting the chiller up. This is visible from my sump room. This is a great comfort to have this reading available to insure I am not overloading the chiller.

I try to keep my suction temp in the 50's as I understand if it is above 65 for very long, compressor damage can result.

[cseeton]

AcroSteve, grant it, I don't know the details or design of your DIY chiller system, but I don't see any problems with running suction temps even into the 80s - it would just mean that you have a very good heat exchanger (or it would indicate that your system is leaking and has a low refrigerant charge, although a suction pressure would be a better indicator there).

Low suction temps indicate that you may have a poor efficiency heat exchanger, an oversized system, fouling due to calcium buildup, or ice formation on the water side.

[sidewinder770]

Originally posted by NOLACLS
All you people with equipment rooms really make me sick I have to stuff my stand....

It will definately make it easier in the end but it's also a lot more work setting it up. Knowing the type of setup we wanted ruled out placing everything under the stand from the start. I must admit though- I have seen some impressive cramming of equipment into stands.

Fliger- Thank the monsoon for the temp drop at 8pm .

AcroSteve & cseeton- I messed around with the chiller last night and here is what I ended up with for temps- let me know what you think (these temps are taken from a temp guage strapped to the pipe). Chiller input temp (right after the TXV) is about 39.6-40.4. suction temp about 4 inches after the chiller- 53.4-54.6. I was suprised how much I had to dial the flow of the water back to get it that low- a very rough guess but I would say in the 800-1000gph range....but I could be way off on that. I could go lower but I think that may be about right? I am also able to get a little more temp variation between those 2 readings by adjusting the TXV a little (It has an external adjustment screw). I still need to put the gate valve on the water output instead of a ball valve so I can fine tune it a bit more but I should be able to get about 38 on the input and 54 on the suction. What kind of temps are you guys getting? Should I be concerned with temps at any other point? Unfortunately I don't have a set of gauges to hook up to the low and high pressure ports but the unit itself seems to be running nice and quiet. The way it was setup the first night the chiller input temp was about 52 degrees and the suction temp about 64 so I think it will cool even faster now and be better for the compressor. The suction line (where it goes into the condensing unit) is cool and sweating- I would say about mid 50's- does that sound about right? The pressure line coming from the condensing unit is warm- not hot but I would say 110-120. The ambient temp outside at the time was about 102. I'm just learning the whole HVAC thing so any advise anyone could give would be great.

[cseeton]

Let's see... An evaporator temp measurement of about 40 is ok, and your superheat of about 15 degrees is a little high. Try raising your evaporator temp to about 50 and play with the TXV to keep at 15 degree temperature rise. This will allows allow your minisplit to run a little more efficiently and will increase its capacity.

There is no need to dial back your water flow. Let it stream through there and increase the LMTD (fancy way of calculating temperature difference). There is no need to have "cold" water leaving the chiller tube, water has such a high heat capacity that the heat is removed without such a big temperature difference. Obviously though it needs to be lower than your desired temp but give it a little time, your system is large and will take few minutes.

Don't worry about the compressor, it will be fine if your AC guy put the correct TXV inline (they are sized for system and work well, try not to play too much with it). The suction line should be insulated and not dripping while your liquid line (the line from the condensing unit) will be about 5-10 degrees above the outside air temp.

Oh, I just read the rest of the post.... try and get back to the original settings of 52F chiller input and 64 exit. That is a good setting and falls with what I said above...

[AcroSteve]

This thread was a great help to me.
http://www.reefcentral.com/forums/sh...on+temp+damage

In regards to higher suction temps, I took the advice of someone that made a lot of sense to me at the time. Check out robthorn's post on page 9 at 06/24/2003 09:09 AM.

There are several good pages of technical stuff around there too.

Check this thread too.
http://www.reefcentral.com/forums/sh...hlight=chiller


The way I see it is, you are overloading your compressor and shortening it's life by subjecting it to greater internal temperatures. Your way may work for a few years, mine may work for 10+. It is hard to tell, but I am playing it safe. I think I am running about 600 gph or less.

By changing my flow through my chiller, I can make my suction temp anywhere from below freezing, to whatever the tank temp is. Right now, my suction temp is aroung 55 degrees and I feel I have a very efficient chiller.

I took my suction temp readings by zip-tieing the remote probe from an indoor/outdoor thermomter to the suction line right before the compressor, and under the insulation. This is still in place today. I did not leave any gage in place.

My system has an orfice, not a TXV, so I cannot give you any real experience with adjusting it. Other than to say, the TXV is better. Get a gate valve before you spend much time adjusting things

You should consult a local HVAC tech with gages to properly set the refrigerant level. The will check the temperature at the compressor suction, and the high and low pressures. These are the minimum requred to calculate what is called "Super Heat". This value should be less than 10.


But.. before you do much else, do yourself a favor and take a few hours to read those two threads.

[elephen]

Looking good man. I'm tagging along, cant wait to see it filled up with water!!!

[cseeton]

Acrosteve,

I would love to discuss your 65 degree problem in more detail since I think someone gave you some unclear advice on a temperature, but I do not want to tie up this tread. There are some very good tips in your first link, but for people reading this - if you want to do a DIY chiller - hire a licensed professional. You need an EPA license to work with refrigerants. This will prevent you from not correctly charging your system and possibly have it fail prematurely, sizing one of the components to cause system failure, or - worse - injuring someone due to it being overcharged to pressures near the burst of the metal lines or the compressor shell.

Chris

[sidewinder770]

Don't worry about tying up my thread- post away all you like. I'm sure other people would like to hear the discussion about this as well. I appreciate both of you posting your knowledge and appreciate your time.

AcroSteve- I have read those two posts a few times- I probably wouldn't have even attempted this set-up if I had not read those threads as they contain some very useful information. I was doing a little different of a setup so I wanted to make sure I was on the right track- the other threads didn't use 1/2 of a mini split or a TXV so I wasn't sure if things would be different because of that. For anyone trying to do this setup I would definately check out those 2 threads.

Anyway- I got the gate valve on yesterday and probably wont fire up the chiller again till I get some saltwater in the system. I have a few smaller projects to get done here and there in the sump room and need to start on the canopy / lighting but I am currently still waiting on the skimmer which will probably be 2+ weeks from being finished still.

I'll post more pics as I get more done.....I am just ready to have water in this already and can't wait for the skimmer to get here!

[cseeton]

I still maintain that anyone trying to DIY a chiller tube, needs to hire a professional to correctly charge the system. But, I also know that there are alot of people that will not yield my advice and do it themselves anyway.....

Since I do not want to be the one that "cseeton on reefcentral told me how to do this...", and you do it wrong and the system breaks. I will refer those interested to this online trade article:
How to Charge an Air Conditioner

I do not want to toot my own horn, but I am getting my PhD in refrigerant/lubricant properties, i.e. compressor lubrication. And I will tell you right now that the temperature fo the refrigerant entering the compressor being too high is not a concern. The concern is why is the temperature too high... Usually, high suction temps occur because the system is undercharged (has a low suction pressure, high superheat) or the evaporator is a high efficiency design (normal suction pressure and correct superheat). Now you can see that there are two different reasons (one bad, one good) for inlet temperatures and without knowing the correct suction pressure (and therefore, superheat) there is no way to know what is happening. You will never see a HVAC tech without his gauges (and if you do, get another one) to determine the superheat and operation of the system.

As far as the suction gas "cooling" the compressor... there is not enough energy left in the stream to provide much of a cooling benefit to the compressor (it is a gas with virtually no capacity). The compression process generates a great deal of heat on its own and the compressors are designed to have this heat carried away in the discharge line or have a fan cool the compressor shell.

For those still really wanting to their own DIY chiller, a TXV is the way to go. Yes, these cost a little more, but they really help the DIY person because they take one thing out of your hands... These systems are charged for subcooling since the TXV modulates the superheat. In addition, if you live in climates where the temperature drops below about 65F, then you will need to get a head pressure controller and a crankcase heater. These devices are not too expensive and will allow for year round operation of your chiller. The head pressure controller (electrical version with a 10K thermistor) and crankcase heaters are also electrical so they can be added to currently operated systems without disturbing the refrigerant lines.

So, my recommendation is to purchase all the pieces for your system - condensing unit, or window AC, TXV, chiller tube, and for those inclined, refrigerant tubing (keep it clean!!). IF you feel comfortable putting it together then go ahead, but don't make the final connections to the condensing unit. Hire a HVAC tech to make a call. He will make the final connections, pull a vacuum on the system and either release the refrigerant from the condensing unit or charge the system. At that time, if you are uncomfortable with electricity the tech can also connect the head pressure controller and crankcase heater. Be absolutely certain that you keep water out of all components if there is a time lag between the tech getting there and when you piece together your components. The number two killer of AC systems is water - right behind overcharging. Keep an eye on your system for a while, if you see your compressor "sweating" or frosting, call your tech because your system is likely overcharged or frozen and will need adjustment.

[cseeton]

Oh, if you are using a window AC as you condensing unit. Do not cut the tubing. Let The HVAC tech do that for two reasons, first it is illegal to vent refrigerant (the tech will reclaim it) and, second so that water will not absorb into the lubricant during the time it is open to the atmosphere. Just bring the tubes from the chiller tube to the unit. Water will also freeze inside the system and clog the expansion device (cap tube, or TXV) so it is very important that the system stay sealed until the final connections are ready to be made.

[AcroSteve]

Good information!

If we could discuss this a little more, It might help us understand it a little better. I will simplify a little bit, so as to avoid over-analyzing it.

Regarding the load on the compressor;
Let's consider that our tank water temp will be constant. I say this because for all practical purposes, and in most cases, we are working with a temp range of one degree or less. Therefore, the only way to change the load on the compressor, is by adjusting the water flow through the heat exchanger.

In my situation, I charged my system to a certain superheat value using a load that was not precicely known. I estimate it was about 600 gph, but I have no way of being sure. I do not have my notes so I cannot quote any specifics, but my high side was around 250, and the low side was around 65. As I mentioned before, I kept the sution temp in the 50's.

I have a fan cutout switch that is currently set at 200psi with a span of 70psi. I did not incorporate any heaters or head pressure controller. It has worked fine for 2 winters now, but I do cover about 80% of the condensor area in the winter.

Enough of my rambling. now a few questions for you cseeton.

Given that my compressor is a 5200btu window unit(and the source of my capillary tube) and I am using a 1/3 hp chiller barrell, should I re-connect my gages and check and or re-set my pressures and superheat? How much load should I place on my compressor for the most effecient operation? What suction temperature would you "shoot for". Would you choose different setpoints for the fan cut-out switch

Additionally, my chiller is fed from my return pump, so any increase in the flow through my chiller will come at the expense of flow to my tank. Therefore, I would be better off with the least amount of flow though my chiller that will still get the job done.

With my current level of charge and chiller water flow, my chiller is dropping the water temp of my 250 gallon system 0.5 degrees in about 15 minutes. Should I even be concerned with it? Still, answers to my previous questions will help myself and others in the future.

What made you pick this for your PhD anyway?

[AcroSteve]

Originally posted by AcroSteve
I do not have my notes so I cannot quote any specifics, but my high side was around 250, and the low side was around 65.

ha!

I swear I did not read the article you linked to 1st.


Thanks for the link btw.

[cseeton]

What made you pick this for your PhD anyway?

Boy, I wish I knew... It just kind of drew me in.... I worked for a number of years before I came back to school and I guess a quote from my old boss got me started. "image this, here we have a system that uses industrial grade solvents, mixed together with a lubricant, dirt, water, and other unspeakables... It is really a small chemical processing plant. We are limited to only to an initial oil charge, while with every other piece of industrial equipment we can filter or change the oil,. AND, we expect this system to operate for a minimum of 10 years without failure in the cold of winter and the extreme of summer. Now, if we don't get it right, or even have a hiccup, the consumer will pound on the door and demand that it is fixed now and compensate him for the losses. How is that for a tough challenge...."

Anyway, on to your question. If I remember right, in your attached thread you said that you are using a R22 system. A high side pressure of 250 corresponds to a condensing temp of about 115F (if you used a gauge set, you can read the corresponding temp from the scale corresponding to your refrigerant - green in my case). Now, a suction pressure of 65psig corresponds to a temp of about 38F and if your suction temp was in the 50s, your superheat was between 15-20 degrees. But since you measure it at the suction instead of the evaporator exit, the superheat is probably a little lower. That is ok.

Should you reconnect your gauges and try again? NO. Your system does not sound like it is far off the mark. I would try to flow as much through your chiller as you are comfortable with, the more the better. Just do not drop your flow so low as to let frost form on the exit line from the chiller tube...

Your fan cutout switch operates the same as a head pressure control, it just uses pressure as the parameter instead of temperature. These are usually a cheap alternative to the electrical control, but you have to set it up when the system is not charged. If the system is charged, I recommend the electrical control since a service call will easily cost the difference.

High suction temps are not a problem, low suction temps are a big problem. There is no maximum temperature for the suction inlet; it just depends on the system, the load on the system and it could be an indication of low charge. Find high quality gauges and use them.

[AcroSteve]

Thanks for the explanation