Hydronic System - "Whoosh" Noise

hot_rod

Often when velocities exceed 5 fps you will start to hear flow, especially in copper tubes. If the valve is "shearing" off excessive an excessive flow rate slowly I'd bet that is what you are hearing.

A delta P circulator is one fix. Or a PAB valve if you want to stay with the circ you have.

Redrum

Paul and HR - A few posts back I recorded the "whoosh" if you care to listen. It's perfectly in sync with the closing of the valve. The recording sounds wimpy compared to what it can sound like, but the characteristic of the sound comes through.

I had been thinking that if I could wire, or program the hydrostat, to stop the pump during zone valve transitions, then restart, I would not have this problem. maybe it's time to buy a bunch of relays and an arduino or Rasberry Pi and build my own!
Jim

sunlight33

Don't do forced air, please.

hot_rod

Yeah, that recording doesn't do the sound justice
But we all know what shutting off a high flow of fluid sounds like, especially if it is a slow close.

As a ball valve "shears"off the flow it presents a sharp edge to the flow, so with proper, to improper, conditions you could develop velocity, possibly cavitation noise.

Really the simple fix is a delta P circ pump. Your system will run much smoother regardless which zones or combinations of zones are flowing. And it will save you electrical energy to boot.

Redrum

sunlight33 said:

Don't do forced air, please.

SL - I was just bluffin' I love my hydronics, especially the Buderus with the silent pump, no gurgles, just the pings of metal expansions, even heat, and the energy bills significantly lower... Until the "whoosh" that is....

I was serious when I said if there was a control that could shut down the pump if any ZV is to transition, then restart once transition is complete, then I would be back to completely silent.

hot_rod

I was serious when I said if there was a control that could shut down the pump if any ZV is to transition, then restart once transition is complete, then I would be back to completely silent.

But you have multiple zone valves, would you stop and restart the circ every time any or all valves cycled off? That seems like a band aid, treating a symptom, not the cause of the problem?

Redrum

I agree HR, but the 1-2 second interruption of flow, which includes more start/stop cycles on the pump, what can it hurt in the long run, when zones are not opening and closing rapidly...I know less starts of motor equals less energy....anyhow, just a thought. If a delta p pump would solve, great, but I thought someone had commented that the response slew might not prevent the noise...or did I dream that?

Anyhow, I do love technical problems and I tell myself this is fun, so tomorrow, new experiments and tests focusing on is more/less securing of the field near the boiler and see if that makes a difference. We'll see what tomorrow brings.

Thanks all
Jim

hot_rod

Good for you taking on the challenge, let us know how you make out.

If you can run down Jim Erhardt, he worked at RTI back in the 90's, and SlantFin, he may still with Watts now. Sharp fellow, he had a patent years ago, on a control to do exactly what you are asking, along with other hydronic patents.

I had one kicking around, if I can find it I will send it your way.

http://patents.justia.com/patent/4863100

Mark Eatherton

Jim is with Viega now. I think he is one of their hydronic trainers if I am not mistaken. I will send him a note on FB and tell him to check in here. He used to be with Buderus.

ME

Redrum

HG - after my last post last night, and after reading through a thread that some of you participated in in 2014 (specifically the last post):

http://forum.heatinghelp.com/discussion/148951/are-taco-zonesentry-valves-noisy

I had a thought about HR's recommendation of a purge and balance, and the mention of it in the thread by IS being an issue.

My system on the return has - ZV's -> T's -> 1 1/4 manifold -> Single PAB -> elbow -> Air Separator (with tank and vent) all within a 4' run.

I was thinking two things:
1) Is it a proximity issue?
2) Can I play with the balance part of the P&B?

Proximity - it was stated earlier, and in older threads that the air scoop and the tank should be on the supply side, on the suction side of the pump, is this still the consensus? Not only is my scoop and tank on the return side, it is after an elbow, no 18" of straight run, AND, it is immediately down stream of the valves that are pinching off the fast moving water. Can this be a suspect?

I have reattached my picture that I marked up a bit for convenience.

Balance - I went downstairs and adjusted the balance part of the P&B, from off, to, say, of the 90 degree rotation, 15 degrees at a time. When it is off, there is the zv sound, no whoosh, at 15 degrees from off, whoosh starts to come into play, then 30 and beyond, full whoosh, no change.

So, HG, I think I performed your test on the return side, later today I'll do it again on the supply side.

It's funny, I am an electronic engineer, recently accepted a retirement settlement in June, and I now do a little consulting work part time. All those years on the bench, sitting over designs, prototypes, product that either didn't work or were flaky, I could methodically isolate sections, rerun the numbers, test, or substitute with known good or instrumentation, and slowly work toward the culprit.

I was thinking about you guys, the pros in hydronics, when I did what I did, I just had to unplug/plug, desolder/resolder, all on a cozy bench. You guys on the other hand have to take the heat down in someones house, drain systems, cut, hack, sweat, pro press, refill, repurge, etc.

My instinct is to solve this the way I am used to, but I really can't (try the pump here, no? Move the tank there, no?). My hats off to you guys.

Jim
Like I said, today I am going to play around with both loosening/eliminating clamps and supports, and adding more, to see if I can get any affect.

JeffM

Mark Eatherton said:

Jim is with Viega now. I think he is one of their hydronic trainers if I am not mistaken. I will send him a note on FB and tell him to check in here. He used to be with Buderus.
ME

Mark is correct. You can contact Jim via e-mail at jim.erhardt@viega.us

Mark Eatherton

Ideally, the expansion tank and scoop should be as close the the pump as possible, but what is more important, is for all pumps to pump away from the expansion tank connection, or what we call the point of no mechanically induced pressure change (PONMIPC). Your pump meets that criteria of pumping away.

Also, when separating the expansion tank and the pump with considerable piping as your system does, a slight pressure "droop" occurs, but it can't draw the water pressure low enough to cause air to be sucked into the system through the automatic air vent, especially in your case, because the boiler has such a low pressure drop factor to it on flow. If it were a high pressure drop boiler circuit, then yes, it can drop the pressure low enough to cause air to be induced, but that is a fairly rare phenomena that I wouldn't concern yourself with.

Honestly, I think it keeps coming back to the piping. Not enough pressure drop through the system to create reasonable flows. You have to create resistance on each circuit to get the flow and velocity down to a reasonable factor. If you do that, and base operation on a 20 degree differential, and the noise still exists, then it may be time to consider zone valve replacements, but as noted, any valve that is dealing with excessive flow, as your system is, can expect some noise on close off.

Many years ago, I had a commercial apartment complex that had a huge diaphragm expansion tank on it. When the pump would shut off due to high OSA temperatures, there was a huge SWOOOSHing noise coming from the expansion tank. Come to find out that there were numerous other expansion tanks out in the system, and the water pressure was equalizing between the other remote tanks (district heating system) and he main boiler room expansion tank on pump shut down. I doubt that it's the case with your system, but thought it worth mentioning...

ME

Paul48

According to Taco's documentation, the travel time, open or close is 5 seconds. Do you get the whoosh if you open a zone manually, then close it manually? Five seconds seems very slow, but I guess if you don't have a problem, it's just fine.

hot_rod

Lot of opinions out there on how to pipe a hydronic systems. Here are some generally held best practices. Assuming a load calc was performed and the boiler sized accurately.

As best you can define the piping circuits and select the circulator based on the actual system requirements. There are some forms to do that calculation or some simple software programs.

Pump away from the expansion tank so the system sees the increase in pressure from the circulators delta P (pressure), see the example below. This relationship can make air removal simple, or a challenge.

In some cases it is best or suggested you pump into a boiler, high pressure drop boilers, if so the expansion tank moves to that location. Tthe expansion tank does not need to be mounted on the air purger up top.

Install a quality air removal device at the hottest fluid location, at the boiler supply ideally. Many installers prefer a micro bubble type air separator, compared to the ramp type purger you have.

A manual or semi automatic air vent at the highest point in the system, possibly the upper floor baseboard piping.

Dirt separation is a good idea on all systems, you can get 2 or 3 in one devices that provide air, dirt, and magnetic separation.

Zone valves on the supply side, downstream from the circ pump can prevent unwanted ghost flows.

Service and purge valves in critical locations to speed service, if needed.

Pipe insulation is the gift that keeps giving, unless you want or need that piping heat loss near the boiler?

I don't know how deeply you want to get into re-piping a two year old install, or get in a finger pointing back and forth with the installer, the system does provide adequate and comfortable heat, it sounds like. The noise issue can be eliminated without a major repipe, it depends on how much you want to change, to improve some of the above.

Now that you are learning some of the finer points of hydronic design, you may lie awake at night until you make some adjustments.

Paul48

I think he is trying to eliminate "maybe" as his possible solution, and I don't blame him. Maybe, because Taco has seen this problem many time, they should consider changing something with this zone valve. Perhaps a faster valve action would alleviate the noise.

Mark Eatherton

Paul48 said:

I do Mark...........If I read you correctly, you are saying the noise is being created by velocity change at the closing zone valve? Doesn't that also indicate a pressure change at that point, and is there a way to cushion that? Just thin'in

Paul, there would be a quick change in pressure, but you'd need a pressure gage upstream of the valve to see it and it would dissipate real fast.

I just listened to his audio file and it is exactly what I have been saying all along. Flow being sheared off. I am not certain that even applying a DT pump would make a difference due to the lack of back pressure from the use of all the 1" pipe. Those pumps are a steep curved pump, and even sitting on their haunches would push a lot of fluid... A Pressure active bypass might help, but who likes driving with one foot on the brake and the other holding the accelerator to the floor board...

Choke flow to a 20 degree differential and if its still noisy, go back to a different style/type of ball valve.

ME

hot_rod

Paul48 said:

I think he is trying to eliminate "maybe" as his possible solution, and I don't blame him. Maybe, because Taco has seen this problem many time, they should consider changing something with this zone valve. Perhaps a faster valve action would alleviate the noise.

The fine line is a faster closing valve can induce water hammer. Most spring return valves like HW, etc are 5-10 second close.

Redrum

Paul48 said:

According to Taco's documentation, the travel time, open or close is 5 seconds. Do you get the whoosh if you open a zone manually, then close it manually? Five seconds seems very slow, but I guess if you don't have a problem, it's just fine.

Wow, when you are totally intent on solving a problem, it sure does help to peek from under the blinders some time. Thanks Paul (and everyone of course) for the great thoughts and ideas. Paul, a great thought to manually actuate the valves. I was so focused on not cutting the electronics of the ZV out of the equation, I forgot to realize that manually you can vary the speed of closing that you can't through the stat.

Here's todays findings:
1) I have attached two audio files in the zip - back porch zone open, basement zone closing, manually, both fast and slow (slower than the electronic actuation time). The findings are that the whoosh is still there, but it is a whoooooshhh as you close slowly, and a "ZOOP" if you close it fast, almost a hammer.

The most interesting part is this - when I closed it slowly and got to the loudest part of the whoooo... and stopped at that position, the loud "ooooooooooo..." would just continue, until I completed the turn.

Note is sounds like I live on a creek, it's raining hard here, and the ground water is flowing into the sump hole

2) I tried to do the same thing with the ball valve past the pump, and the P&B shutoff, and I could not get the whoosh, but did get a little innocuous noise, like you would with a faucet.

3) Another "ah-ha" observation. Remember upstairs, downstairs, and the basement are normal sized loops, and the "porch" is a 1/2" short run to a panel radiator:
http://www.ecomfort.com/Ecostyle-B-24.24-ECO/p24160.html

The panel radiator was just added in December when I finished the porch remodel. I had always heard the whoosh prior to then here and there, but it seemed to get real bad when he had real cold temps in January. I thought it was just going from our balmy December to sub zero January. Perhaps what was happening is the panel radiator was running alot. It seems to me that these panel radiators heat a space slower than a baseboard, which I would assume means the ZV is open longer, but perhaps not as much heat loss. I reasoned that without any scientific evidence, which is dangerous.....Anyhow....

I had always been testing with basement and porch because they were closest to boiler (change stat and run to boiler, where is a kid when you need one?). I decided to try creating whoosh with all zones and found (at least today) that if the porch is running, and you close any of the other zones - loudest whooosh! But, if the porch is not in play, there is a whoosh, but probably what mark characterizes as "nature of the beast" and livable.

So, the system doesn't like closing a 1"- 3/4" long run zone while the 1/2" short run is open, but it doesn't mind closing one big when the other big is open.

Does this sound like I should have a separate balance valve for each zone, or an adjustable bypass for the panel radiator? I have seen them used for panels, but I always thought that you used them to balance parallel panel circuits,

Sorry this is a long response, I can tend to run on a bit.
Jim

Redrum

Paul48 said:

According to Taco's documentation, the travel time, open or close is 5 seconds. Do you get the whoosh if you open a zone manually, then close it manually? Five seconds seems very slow, but I guess if you don't have a problem, it's just fine.

Also, forgot to mention Paul, I took the valve closing audio and put it into an audio editor, from 'click to click' (assume start and close of actuation), it's about 4 seconds, the physical valve move (observed) is about 3, and the whoosh is about 1.5. meaningless info I know, but what the heck.

Redrum

Just read HG's post - went down and ran a test, all 3 pump speeds and the noise is definitely best on "low" and noticeably more obnoxious on "Hi"

one other thing, shouldn't the end switch close, and therefore the pump run when you manually activate the ZV? Mine doesn't

Paul48

The end switch is a dry contact. If the t-stat isn't closed, there's no 24v to pass.

Paul48

@hot rod

I disagree....Snap action valves like solenoid valves can cause hammer. It is difficult to get a ball valve to cause hammer. Even when folks have problems with hammer caused by their washing machine, it can usually be traced to improperly secured piping. My two cents

Redrum

Paul48 said:

The end switch is a dry contact. If the t-stat isn't closed, there's no 24v to pass.

Hi Paul - I can see where the Tstat completes the 24vac to the W/Y and C terminals of the ZV (to energized the solenoid), but I had always thought "dry contact" is just that, a contact, not a power source. Since the end switch is connected to the TW and TR terminals of the beckett aquastat, I had assumed that the ZV dry contact (normally open) would complete the aquastat's 24vac in the aquastat when closed.

That's why I thought you should be able to manually operate the ZV, and have the end switch close, and the controller start the pump. Based on what you are saying, the thermostat is passing power to the coil of the ZV (internal to the valve), which is then energizing one side of the zone switch, which once closed, tells the AS to start the pump. Weird.

I only ask because I have not traced out the wiring that the installers did, and am hoping by not doing so I am not overlooking something, that's all.

Paul48

That's one of those things...there's a bunch of different ways to accomplish the same thing. You'd have to sort out how it was wired. My description was "out-of-whack", but exactly how they wired it is unknown.

Harvey Ramer

How much are you willing to spend to get rid of the sound?

Here are a couple easy things that can be done that will make it livable.

First, throttle back the flow on the discharge of the pump till you get a 20° d-t across the system with all zones open. This should be done with the water temp at the max design temp, and the house at normal temperature. Use the lowest speed on the pump that is able to achieve this.

If that does not alleviate the noise to your satisfaction, install a 1' piece of pex pipe within the copper supply and return runouts. That will act as a sound attenuator to the rest of the house. It is usually the piping material that transfers sound throughout a building rather than the water. Sound travels at 15,180 (ft/s) through copper, 20,000 (ft/s) through steel and a puny 5,091 (ft/s) through 140° water. It should be noted that water acoustics increase proportional to temperature, although they don't get close to solids.

Redrum

Hi Harvey, This issue has existed since the system was installed, so the company I paid the $$ to is on the hook, but I haven't been banging down their door. I am trying (with all of your gracious help and because it's a challenge) to point them to what needs to be fixed.

I am not sure what a runout is, and I think in earlier posts some of the guys thought you would basically have to stop the water to get rid of the sound.

Hi all; A whole lot of great and very interesting things have been suggested, alot of work has been done, and experience shared by all (thank you), and obviously they point to several possible culprits because you guys, the pros, are not standing next to it. If you were, you could stay for dinner

I think it's important to re-calibrate on what is and isn't happening:
1) Pump has to be already running
2) Zone closing causes the whoosh (two zones have to be on, otherwise pump would stop)
3) Zone opening does not cause the issue, or, it is at a very livable level
4) Whoosh is worse at highest pump speed
5) Important! Whoosh is significantly worse when the porch zone (1/2" cu, panel radiator) remains running when one of the bigger 1" zones closes. If it's a 1" remains running when a 1" closes, whoosh is very soft, livable. So, you could say the only problem sound is with 1/2" to panel running while any 1" closes.
6) I honestly don't think this is a specific turbulence in one pipe issue, as the intensity and character of the whoosh remains the same despite different 1" zones closing.
7) this is not an any time any ZV moves thing. It's specific to above.

Fluid physics is right around when I decided electrical was easier to understand, so I have no clue what I am talking about here, but it seems like the system gets unhappy and tells me via a whoosh when it is happily flowing through long 1" pipe, along with a little through a short 1/2" pipe, then, the 1" path gets pinched and all it has is the 1/2". On the other hand, if two or three long 1" routes are flowing and one is shut off, it's no big deal, not as dramatic of a challenge to the system.

An electrical analogy is that the 1/2" is of high resistance, but in parallel with 1 or more 1" which are low resistance, not allot of current (water) flows through the 1/2" as most of it flows through the 1"'s. But, when you quickly take the 1" out, the power (current * resistance) has a quick spike before settling down. This wouldn't happen with two 1" in parallel because both are of fairly low resistance.

So, and I am just going to throw this out there - maybe pipe 3/4" to near the panel then T off to an adjustable bypass some at the panel? It seems like I want the 1/2 to look more like the 1" to the system.

another throw out, separate pump for the 1/2"? It could be tiny.

I don't know alot about panel radiators, but it seems like the heat exchange is less than baseboard, especially with 1/2" vs. 1", but, the temp drop in the water is less. So, what I am saying, is it looks like the panels zone is on longer, pump runs longer, but no more gas is used. Because of this, this zone is bound to be on longer and this situation to happen more often, irritating me more often, so I need to fix it.

I think I am babbling through my fingers. Sorry.

In conclusion, I think with the pump on low, if a 1" is open when another closes, it's as mark says, the nature of the beast, and is probably livable. But, if the 1/2" is the only guy open when a 1" closes, that's the problem

Cheers
Jim

SWEI

Hatterasguy said:

In case anybody was interested in turning a 15-58 or a 007 into a Taco 003:

http://www.tme.eu/en/Document/040bd36f60401826d84e85f734203bd0/Nimbus.pdf

I recently installed this product and am running it at 45%. It is far superior than attempting to throttle the circuit with a butterfly valve. Without the board, there was an incessant low level "rush" noise when the 007 was held back with the valve.

Now, with the valve fully open and the circulator slowed significantly, it's just about silent.

We've been using those for several years to facilitate ΔT control of boiler pumps. http://controlresources.com/ac-fan-control-ac-motor-control-smartfan-nimbus/ is the NJ-based manufacturer. You sacrifice both turndown and efficiency when compared with an ECM circ, but until the pump manufacturers give us some additional hydraulic options and external control inputs for small ECM circs, they're good enough.

Mark Eatherton

Why not just slap a light dimmer on it. I used to use those light dimmers on the radiant windows when I was doing some experimentation. They DON'T like purely resistive loads.

They get REAL hot and the efficiency does suck. Most of the power goes to heat when they are turned down.

ME

Gordy

I was thinking a variable speed control for a,power tool such as a router.

Paul48

Use a Taco ZVC w/priority. Give your 1/2" loop priority, and it will only run by itself, then switch to any other once it's satisfied.

Harvey Ramer

Actually, the solution is simple.
You say the only time the noise is unacceptable is when the 1/2" line is open and another 1" line closes. The 1/2" line feeds a panel rad. Pretty much all panel rads have TRV'S available. Put one of those on the rad and do away with the thermostat and zone valve for that room. Or just disconnect them and leave the zone valve in the open position.

The room will stay comfortable, trust me on that.

Your problem will go away.

Paul48

Too simple I guess.....I don't get it.

SWEI

Mark Eatherton said:

Why not just slap a light dimmer on it.

The Nimbus is a 'smart' phase cut dimmer optimized for single phase induction motors driving centrifugal fans or pumps and controlled by a 0-10V or4-20 mA input (or a temp sensor, or a pressure sensor.) It runs the motor at 100% for a couple of seconds to overcome the startup inertia and then allows turndown to a specified low limit to prevent the motor from stalling.

Redrum

Harvey Ramer said:

Actually, the solution is simple.

You say the only time the noise is unacceptable is when the 1/2" line is open and another 1" line closes. The 1/2" line feeds a panel rad. Pretty much all panel rads have TRV'S available. Put one of those on the rad and do away with the thermostat and zone valve for that room. Or just disconnect them and leave the zone valve in the open position.



The room will stay comfortable, trust me on that.



Your problem will go away.

Hi Harvey, during the initial install, I had considered using the TRV, but since the room was gutted, I decided a new ZV and stat was worth the $200, the ability to go to a digital control on a wall, instead of dialing a thingy on the side of the panel.

I like your thought, but it wouldn't help anything (unless I am missing something). With the pipe loop always open if the TRV wants heat, it's still water flowing through the 1/2", and when a 1" zone opens, then closes, whoosh.

Redrum

The cross sectional area of the 1/2" pipe is (about) 0.8 (sq inches), for the 1" pipe its 3.14. Ignoring the factor of length, when a 1" and 1/2" are running, it's about 4 together. When the 1" closes, the transition caused the area to be reduced by 5 X.

It is during this transition, with the taco ZV, that we whoosh.

That seems like alot, but is it? I'm not sure. Low pressure, Low velocity....

I keep thinking -

If I have 1" running and partially, then fully, even pausing in the middle, close either isolation valve, either quickly or slowly, dead heading the pump. Nothing. Maybe a tiny hammer, can't remember

When Paul had the great idea to manually activate the valve, using the valve is the key, not only did a get a whoosh when doing that using the same timing as the zv would, I got a fast wsh! doing it fast, and most interestingly - when I paused in the middle, and the worst of the noise ("OOOOOOO"), the noise remained. Like when you let air out a balloon and find that perfect spot that makes your dog leave the room. If I left it there, it would continue.

Why? Why wouldn't the system find the new equilibrium, and the noise taper away (like it would if I ran it to close), unless there is a physical characteristic of the valve closure mechanism, or, it is spring loaded and it oscillates?

When you squeak a balloon, you are forcing alot of air through a tiny opening, forcing the compliant mouth of the opening to oscillate. That is why you can squeak for as long as you have air.

The key is what is happening when water is running though a valve that is not open and not closed. There HAS to be an oscillation in order for a sound to continue in my test. Either the closure devices is oscillating, or, water turbulence is being created (water in rapids are noisy)

But, when I did the same thing with the iso valves, nothing. The true test would have been if I had a P&B on each zone, but I don't. If I did, I could have played "is it the valve?"

Just a few morning thoughts. I think you guys who had suspected the valve, along with that previous post I provided a link to, might have been on to something. I think I'll call taco today
Cheers all;
Jim

Harvey Ramer

I don't have the time for a full explanation right now, but if you want your problem solved in short order use the TRV and disconnect that thermostat and leave the zone valve open (panel rad circuit).

You've already had some of the smartest people from Taco commenting on this thread. There is little to be gained from calling the manufacturer in this instance, I suppose.

hot_rod

Redrum said:

The cross sectional area of the 1/2" pipe is (about) 0.8 (sq inches), for the 1" pipe its 3.14. Ignoring the factor of length, when a 1" and 1/2" are running, it's about 4 together. When the 1" closes, the transition caused the area to be reduced by 5 X.

It is during this transition, with the taco ZV, that we whoosh.

That seems like alot, but is it? I'm not sure. Low pressure, Low velocity....

I keep thinking -

If I have 1" running and partially, then fully, even pausing in the middle, close either isolation valve, either quickly or slowly, dead heading the pump. Nothing. Maybe a tiny hammer, can't remember

When Paul had the great idea to manually activate the valve, using the valve is the key, not only did a get a whoosh when doing that using the same timing as the zv would, I got a fast wsh! doing it fast, and most interestingly - when I paused in the middle, and the worst of the noise ("OOOOOOO"), the noise remained. Like when you let air out a balloon and find that perfect spot that makes your dog leave the room. If I left it there, it would continue.

Why? Why wouldn't the system find the new equilibrium, and the noise taper away (like it would if I ran it to close), unless there is a physical characteristic of the valve closure mechanism, or, it is spring loaded and it oscillates?

When you squeak a balloon, you are forcing alot of air through a tiny opening, forcing the compliant mouth of the opening to oscillate. That is why you can squeak for as long as you have air.

The key is what is happening when water is running though a valve that is not open and not closed. There HAS to be an oscillation in order for a sound to continue in my test. Either the closure devices is oscillating, or, water turbulence is being created (water in rapids are noisy)

But, when I did the same thing with the iso valves, nothing. The true test would have been if I had a P&B on each zone, but I don't. If I did, I could have played "is it the valve?"

Just a few morning thoughts. I think you guys who had suspected the valve, along with that previous post I provided a link to, might have been on to something. I think I'll call taco today
Cheers all;
Jim

Taco has done a good job designing a high flow, high shutoff ZV with that design. With any, or all valves there are trade offs. A typical ball in a partially or 80% off position presents two edges to the flow. I suppose under certain flow conditions you could cause turbulence and cavitation as you suspect. Also to turn a ball takes some torque so a gear train is required. As a ball valve gets some mineral build up they get harder to turn so a gear train needs to be engineered with that torque requirement in mind. The gear train can also cause some noise. At the end of the day I think you get a lot of value for the price of that valve, if you need those benefits.

You can engineer, or over engineer:) any product till you are blue in the face, as you probably know.

Search around for highly engineered ball valve designs, for more severe operating conditions, and you will see some of the methods used to eliminate what you have identified.

A characterized ball valve design eliminates some of the noise potential and gives the valve better rangibility when used for balancing or varying flow as a flow regulating valve. Most of the PICCV pressure independent characterized control valves will use some sort of these designs.

For this type of zone valve in typical hydronic applications it should not need a "uber" engineered and more expensive ball design to be silent. But maybe?

Redrum

I am sure you guys will roll your eyes when you see I have posted. I'm getting there myself, but I ran a couple tests and thought I would share the results.

1) Currently whoosh only happens when two zones are running, and a zone is closing, and is exacerbated by pump speed and the smaller zone is the one not closing.

The whoosh never occured when one zone only was open, then closed. Because the pump turned off. I added 10 seconds of off delay to the circ menu in the beckett, and turned zone on, then off. Whoosh! Because the pump was running.

I then repeated this but left the zone open, and closed the isolation valve valve near the pump, and also the P&B near the scoop. No whoosh.

One type of valve (or location) whoosh, the others do not.

Conclusion - it may not be the valve itself, but it is something specific to the ZV, when it closes with the pump running.

2) Again, using Paul's suggestion of manually closing the valve, I was able to actuate it part way for the continual "woooooo" and walk around with a screwdriver to my ear. You could hear the turbulence everywhere, but I "think" it is more intense in the zone that is being closed.

I did notice that the basement zone, which is not really secured very well ('cause it was one of many previous homeowner hacks, and I don't use it much) seemed to be the noisiest, so I think I'll lash it down.

You guys have all had great ideas, and I love the technical background from HR, I truly do being a science geek myself, but to me it comes back to shutting the pump off during zone transitions, and, are any of the controllers out there capable of this?

, even dropping the speed momentarily...

Jim

Redrum

Harvey Ramer said:

I don't have the time for a full explanation right now, but if you want your problem solved in short order use the TRV and disconnect that thermostat and leave the zone valve open (panel rad circuit).

Hi Harvey; - you are the pro, and I am not, so I am sure you are right, but...

I had always thought that TRV's are used with panels in parallel where the trv slowly closes off the panels that don't need to heat, while allowing others to continue to heat, to balance the heat in the room (e.g. more heat in front of windows, less in areas where the sun is shining in).

In order to keep my zone open, and use a trv to choke off the water when the room comes to temp, I would need something to start the pump if it was the only zone needing heat. Also, if it pumped continuously, when it did choke the water off, it would have to bypass somehow. I had thought that in these applications that (somehow) the boiler senses the temperature comming back through a bypass to be near equal to going out, and then shuts off the pump. But, my experience in this area is only through reading.

Finally, the panel zone would still be open when the TRV is open, and when I turned off another zone, I think I would have the whoosh.

I think your suggestion would be appropriate if the panel was in parallel to say the first floor zone, where the panel just warms a cold spot, but it's not the case, the panel is in a small sun room that could be shut off from the main floor.

If I still don't get it, I'm sorry.

Jim

hot_rod

You guys have all had great ideas, and I love the technical background from HR, I truly do being a science geek myself, but to me it comes back to shutting the pump off during zone transitions, and, are any of the controllers out there capable of this?

, even dropping the speed momentarily...

I don't know of such a controller.

Keep in mind the research and data logging we have done shows about 5000 cycles per year for a zone valve in a predominate heating climate. So you are looking at a lot of un-necessary cycling of that circulator in your system.

Knowing some actual cycle data helps a manufacturer engineer a product. So if we shoot for a 20 year component life on a zone valve, for example you would engineer parts to at least 100,000 cycles life..

With that info you go to the motor, or switch manufacturer,for example and have them build to that spec. We put the product on a cycle testing bench and run it to failure.

Not too surprising we found some ZVs from China that cannot make 5000 cycles without failure!

In a perfect world the progressive hydronic designer and installer looks for little or any cycling of components. We are getting very close to that with high turndown mod coins, V/S circulators, ODR and weather predicting t-stats, etc.

Limiting cycling not only extends product life, lessens fuel use, but also provides ultimate comfort. We attempt to match heat input to building loss, exactly.

From how I see it your solution is maybe going in the other direction??