I got my system in yesterday in a semi-permanent fashion. By that I mean the bank still need to come down a bit but I am allowing it to settle one more winter before final grade so for now, I installed the system with the airlines running up and over the bank on top of the ground.

The pump is located at the house, I run 100 feet of 1 inch to the lower outside bank edge which is maybe 2 feet lower than the pump location and there I have my manifold branching off into three 1/2 inch lines. These lines go up and over the bank out to the diffusers. The system is running great at about 9PSI but I have a couple of concerns.

One is that after running just 24 hours, I can hear the air passing through water in the line at the low spot of the 1 inch line as well as just after the manifold valves. You can hear the air making a gurgling noise as it passes by water in the line. I haven't heard of anyone in their posts making a moisture trap like you would on airlines used to paint, etc.. but that seems to be what I need to do here. Anyone with similar experience? The days right now have been hot and humid. The pump (Gast) runs very hot as you know and I am sure the cooling effect of the line is pulling out the moisture and leaving it in the low spot.

My other concern is what effect if any UV will have on the pipes running up and over the bank until next year when I can bury most of it.

Appreciate any help!
Dan

This is the one inch line going to the pond bank - the manifold is about a foot up the bank.

That seems like a lot of water after just 24 hours. The manifold is a foot up the side of the bank, and you hear water gurgling there also?

I don't know if it is normal or not, but if I pull my lines off at the pump while under pressure, some water spray will shoot out the pipes from the back pressure.

A larger pipe will actually likely have more of a problem with water gathering in low places than a smaller one because the velocity of air travel within the line will be much slower at the same CFM for the larger pipe.

I don't know if it is really a problem as long as it is not freezing weather. In freezing weather the line could freeze shut. But otherwise I would think the gurgling would only create a minimal resistance to the air flow. But I don't really know that for sure.

Why not put a tee into the lowest point on your 1" line and add a ball valve which you can open to bleed off accumulated moisture whenever you want?

Yes I can hear it.



That is a major issue for my location. I want to run one of them through the winter and a frozen line will definitely be an issue.



I thought of this and it's easy enough to do now but it isn't going to help in the winter when the drain freezes.

When cold weather arrives you could try unhooking the line at the compressor and adding some RV antifreeze. Unlike alcohol it's non-toxic, easy to obtain, and will not attack plastic and/or rubber lines.

Well it happened - lines freezing already.

I am running this on a timer only at night. About 11PM-8AM.

Now we are having some freezing nights (not even a hard freeze yet) and I have discovered my lines are freezing closed putting back pressure on the pump and no aeration.

I changed the main line to 1/2inch running now underground inside the one inch to the bank (100ft away), it then exits the one inch and runs up the bank (exposed) to the manifold which currently is setting on the ground. I am thinking of mounting the manifold vertically that may eliminate the manifold collecting moisture but I don't know how to stop it from settling into the main line coming up the bank.

I ran the airline from the house for the main reason of not running electric to the pond and also not wanting the pump out on the bank of the pond. I am now thinking I may have to build a house for it and mount the manifold directly off the pump into the water so as not to have any region that can collect moisture (no low spots).

I am currently running 3 diffusers but will go to one in the winter so I keep a small area open and the rest can freeze over for skating.

Looking for ideas and thoughts - anyone encounter this before and have a solution?

How about installing a 1/2 x 1/2 x 1" Tee in your airline at the lowest point. On the 1" side of the Tee, install a simple 1" 24v irrigation valve (~$15) and run the 24v wiring inside the 1" poly line to your Gast pump location where you can install a simple 4-zone Orbit indoor/outdoor irrigation controller (~$39). Have your irrigation valve closed when your Gast pump is running and open afterwards for draining condensation. You could even cycle it open/closed multiple times over a 24-hour period if necessary.

The trouble I think with the vent valve is that the lowest point is underground inside the 1 inch pipe.

It was mentioned to put in antifreeze which wouldn't actually solve it but would a little bit mix with the water already in the line to keep it from freezing? I doubt the winter months will be adding more moisture to the line - I think it was the humid days of summer that caused it.

90+% isopropyl alcohol is used to unfreeze lines, and it also absorbs water. That's what is recommended by the aerator mfg's.

Unhook the line, pour a cup into the line, hook it back up.

Or get the freeze proof devices that Koenders sells. It automatically dumps iso into the line when pressure increases.

I guess I am a little bit old school on stuff like this. I hate to keep fixing things over and over. IMHO If I have spots in the air line that are freezing up it is because I have "traps" or low points for the moisture to collect. Eliminate the low spots and provide a continuous grade on the air lines. To quote 10X "These lines go up and over the bank out to the diffusers." Cut the lines thru the bank to keep the downward grade and eliminate the "traps" to fix the problem instead of continually fighting it year after year?

I guess I didn't understand the technique - I took this to mean - "shut down for the winter and put in antifreeze". Not "put it in to absorb the water and keep running the system". I will pour some in and see if that cures it.

I will also look into the freeze control system.

Thanks!

If I cut through the bank at the level that the line is, I will be in about 7-8 feet of water. I don't know of any way to cut through the bank with the lines and maintain the integrity of the bank while doing so. Maybe there is a technique for it but I can picture a damn breaking or a leak forming by running it through. Wouldn't that give the water a nice straight path to leak? They cut a "key" around the perimeter when they made the pond to eliminate any direct path for the water.

Hope you understand I am just throwing out possible options. I always look to find a permanent fix for things. Here is another option for you....run an electric wire thru the existing airline pipe to the top of the bank and put the pump there. You have a 1 inch pipe already which is plenty big enough. You would need a way to house the pump but that is cheap. Run a little bit bigger wire and you now have an outlet for electric at the pond should you ever want one. That is what I did at my place.

I did give that some thought Bill - one of the reasons for running the one inch "conduit". I ran a pull line along with the 1/2in airline just in case I ever want to run anything else out there but the way the bank is, a house for the pump would not be very aesthetically pleasing but may be something in the future when they come back and re-work a few areas for grade so I haven't entirely ruled it out - but not going to happen this year.

freeze control unit

One more thing - with the line running on top of the ground like that, it is vulnerable to rodents chewing on it. Squirrels are bad for doing that around here.

Thanks for the info on rodents. The main line is buried now from the house to the pond but is exposed at the bank where it comes out of the ground to the manifold and into the water. Never thought about squirrels chewing it.

I've had them walk out on the ice during winter and chew on the duck decoys that are marking the summer diffusers in the pond.

FYI if you can not find or have access to Isopropyl alcohol, wood alcohol will work as a substitute.

Thought an update would be in order.

I bought the Koenders system as they said although it is designed for windmill systems it should also be OK for mine. This morning I proved that wrong.

Looked out at daybreak and I had aeration (temp dropped to 28 in the night). About an hour later - I looked and NO aeration. I ran to the pump to see what was happening (it is located inside an attached shed) and the gallon of alcohol was gone from the jug, the pump sounded sickly, and the pressure wasn't reading. I quickly shut off the pump and when it vented - it spit alcohol right out of the muffler! I removed the airline and ran the pump - it had no head pressure for a bit them started spitting alcohol and eventually cleared itself. I then hooked the line back up and went to the pond and opened a fitting - almost no pressure for a bit and then out came alcohol.

After some time, I got all of the diffusers to work again.

Your first thought will be that I had it hooked up wrong - this is not the case - it is plumbed in properly. I do not believe this is going to work for my setup.

I guess I should have just built a house at the pond and ran wire out there for the pump and I believe that is what I will do next. I want to run one of the diffusers all winter so I have to solve the freezing issue asap.

I can see where water in the lines would be a big issue.

The standard recommendation is to make sure all air lines run down hill into the pond so there are no low spots for water to accumulate.

Yeah right. Good luck with that one. Maybe if the pump house if right near waters edge. But at least with my level of skill running a trenching machine and not wanting to get a laser level out and hand level the bottom of the trench, good luck in getting a line that is installed perfectly enough so there are no low spots that will hold water. Putting it below the frost line would cure the freezing problem, but just looks like running an air compressor through the winter is problematic and would require some babysitting.

Isopropyl Alcohol is best, RV antifreeze is OK, but it takes more. Compressed air creates a LOT of water condensation. You may try adding an inexpensive, automatic water separator on the output near the Gast pump. If possible, run a loop line to let the air cool and condense the moisture before it enters the separator/ejector.

example... https://www.youtube.com/watch?v=A8JwN0l-_pA

Is a switch to a piston type compressor feasible for your application? They don't run nearly as hot as your rotary, and shouldn't create as much moisture. be advised that if alcohol enters the comp. or comes into contact with rubber or plastic parts, degradation may occur.

Also, alcohol is hygroscopic, meaning it has an affinity for moisture. Yes, it functions as an antifreeze, but it also attracts moisture.

OK - didn't take long to move the pump to bank and run directly into the manifold - everything is heading down into the water now. With the heat of the pump, I expect all to be OK as far as freezing now. I put a plastic cover over it and left one side open for the manifold. I figure I can change it back in the summer - just one more prepping job when winter comes each year.

Now for the new problem - I think it is anyway.

I am currently running 3 diffusers and plan to use just the shallowest one thru the winter. I just closed off the other two for a quick check and hear my pump clearly go from an "idle" to definitely building back pressure with only one diffuser in use.

Is this an issue? Should I do something to vent some pressure when I go to one diffuser? If so, what is the best method? I can just pull a line off and use the manifold valve to bleed it if that is acceptable?

10x, higher pump pressure means much more pump wear. You can use your pressure gauge and simply dump some air to reduce flow/pressure to the single diffuser.

I am sure you accounted for this but, just in case, does your plastic cover provide for good ventilation to the compressor? They can over heat, even in winter, without good ventilation.

Thanks for the info - yes, the side that is open is plenty large for ventilation but thanks for the heads up - I will monitor closely for a while.

I will just open one of the other valves with the line removed to dump air when I change to using one diffuser this winter. Just wanted to know if that was an acceptable way of relieving the pressure.

That's how I did it last year and it worked fine. Just make sure you cover the end of the airline you disconnect to keep stuff from getting in there.

It works fine, but the constant hiss of escaping air is maddening. To a mechanic, anyway.

Accumulating back pressure when using just one diffuser indicates the diffuser does not have enough holes to allow all the air to escape. Enlarge the diffuser for next winter's operation. Why waste the air when it could be creating a larger ice free area in the pond?

It's even more maddening to a dimwit like myself that these compressor companies keep churning out canned electric motors that you can't do a darn thing with to vary the output to meet conditions. Oh, I could rant on this for hours!!

Could you possibly use a medium to coarse bubble diffuser for winter? That could possibly let more air out to clear ice, and just open a winter valve?

Awesome thought! Had not occurred to me. If my well pump can run at whatever speed it takes to maintain pressure, why can't my aerator pump. Let me know when you start looking for investors man. I'm in!

I would imagine those off the shelf motors are relatively cheap, but I do like the idea of variable control. Wonder if the compressor efficiency (from an air-producing standpoint) would decline as rpm dropped? ( more time for leakage as rpm decreases)Seems like it might be more of an issue for rotary compressors vs. piston, but then again as the cups and valves wore I would expect a loss there also.

Sometimes higher rpm can compensate for worn components. For a time, anyway.

Affinity Laws.
I recently bought a little 1/3hp Marathon 3 phase motor to adapt to one of my pumps. This sucker will hold zero speed with full torque from one of my PowerFlex 525 drives, and zing to whatever you want it to do within it's threshold. I don't think I can truly explain how awesome some of this stuff is.

I agree. The variable speed would definitely require a fixed displacement pump to make sense. Theoretically, when subjected to a constant load (back pressure), pump life for a fixed displacement pump is determined primarily by number of cycles. When parts start to wear, the motor would need to run faster to compensate for the loss in efficiency. The speed control input would either need to be pressure or flow.

This is one of the few speed controls that will work with some of the single phase compressors: Dart 55AC

I was going to order one last spring for my 75R compressor, but never got around to it.

There are some VFD's available, but price is outrageous, and you'll fry these PSC motors from Gast.

Not necessarily. Rotary vane compressors are quite popular in factories for supplying required air flow at a constant pressure.

Look at the graphs for the Gast rotary vane and you'll see what happens when you change the speed.

Sorry. Poor choice of words on my part. I should have said positive displacement not fixed displacement. A variable or fixed should work as long as it is a positive displacement type of pump.

JKB,

I agree a vane pump would work. They are also a positive displacement pump. Pumps that I think would not work as well are centrifugal pumps for example.

Rotary vane compressors are kinda sorta like a positive displacement compressor, but not true in nature as a piston compressor would be.

The affinity laws would not apply to either of these, but they would on a centrifugal water pump and air moving devices like fans and blowers. Ring compressors (Regenerative Blowers) are a different animal as well.

Nice thing if you get a decent VFD to run your pumps and compressors with, you don't need sensors for pressure or flow. SVC (Sensorless Vector Control) has made some pretty impressive improvements over the years.

What I mean by a canned motor is one specifically made for each of these compressors and will not fit much else. Privy and exclusive to the manufacturer.

Now, what I would like to see is these people adapting NEMA (off the shelf) motors so we all have options.

I think I mentioned the small motor rule that took effect this spring, but these guy's squeaked by that so you'll all have to live with it. It was actually a screw up on the gub part, but think private dollars to the right people played a major role

If a person uses a moisture separator, it would be important to remember the separator itself would need to be protected from freezing somehow.

If a person could add a relatively large air tank after the compressor and before the air line with the air running through the top of the tank (so the air has a chance to cool and condense before entering the air line) with a drain on the bottom (that could be drained in above freezing temperature times) it might help. Another form of moisture separator but would not hurt to freeze in the bottom of a rounded bottom tank (horizontal type tank like a tire air bomb) as long as the water level was not over half full. Some alcohol could be added to the tank to prevent freezing. That is what truckers do to the air brake lines and air tanks in freezing weather to prevent their air brake type brakes from freezing up.