venturi noise

[st18901]

Is there anyway to quiet the venturi ?
When they're fully open, they're really loud. Remember, this is my HS "very classic" spa, so maybe this has been addressed in the twenty odd years since.

If so - Terminator, Spaman, Drewster, anyone who might be knowledgable - what are some tricks?

[Spatech_tuo]

Terminator, Spaman, Drewster- what are some tricks?

I can't think of how you could alter them so I'll leave it to the experts.

[NJDave]

It's funny, back in the day, we called them "Silent Air Controls". But, there was nothing silent about them. They do whistle when the controls are open and will stop when they close. Yes, things have changed since you purchased your Hot Springs Classic 20 years ago, heck I think Terminator was attending Hot Tub High School, back in 1985,when your spa hit your back yard. Now he is relaxing Texas backyards one at a time. Just having fun Term. Some air controls had a rubber check valve, that can break down and allow more air to pass, hence causing the whistle. Some air controls have a plastic ball, acting as a check, to prevent water from pushing up through the control, sometimes they stick in the down position. Other older air controls had a spongy black or grey material, to cut down on the whistle, as they get older the material breaks down. Not a lot you can do to quiet down a control, short of repalcing it. You could always turn up the tunes and bleed it out. Goodluck. Dave.

[drewstar]

Thanks for the compliement  of "expert" but please don't confuse me as an expert: Just a enthusasitc user who is also still trying figure out quite abit.  

I am not familliar with the venturi systems on the hot tubs, and the last time I worked with phenamatics was about 20 years ago on some laser test beds.

Venturis are inherently noisey. You may want to take at look at  what i am assuming must be a manifold-ish intake and ensure it's not cracked and everythig is seated correctly. as well as any hoses if they are craked or brittle. As  Dave said pehraps some type of   foam, but I would also cautiuos about with the pressure.

If the noise you are hearing is more  of a banging rather than a loud intake,  could it be a symptom of pump cavitation?  (air bubbles against an impellor blade?)

Make no doubt about it, I am  wild  a -s-s  guessing here....

[st18901]

I don't think there's anything wrong with the venturi system. It quiets down when I close them. It just amazes me how loud they can get.
I'm thinking of trying to sound proof the filter/weir area and even add a top flap weir so that the opening is minimized. It gets a lot quieter when I put my arm in across the front of the opening.

Heck, I was even wondering what it would be like if I ran hoses off the venturi intakes and away from the tub.  (though after all that restoration work, I don't want the spa to start to look like something out of Terry Gilliam's "Brazil".

[drewstar]

I don't think there's anything wrong with the venturi system. It quiets down when I close them. It just amazes me how loud they can get.
I'm thinking of trying to sound proof the filter/weir area and even add a top flap weir so that the opening is minimized. It gets a lot quieter when I put my arm in across the front of the opening.

Heck, I was even wondering what it would be like if I ran hoses off the venturi intakes and away from the tub.  (though after all that restoration work, I don't want the spa to start to look like something out of Terry Gilliam's "Brazil".

I was thinking that might have some effect too, but  wouldn't you see a drop in pressure if you made the hoses too long?

[Soakin]

...Terminator, Spaman, Drewster, anyone who might be knowledgable - what are some tricks?

No offense intended to your "experts" but... .   Since TUO and NJDave have already weighed in, you might want to consider a PM to Chas, Pkud and Stuart.  They aren't posting as much as they used to, but they always seem willing (and able to lend a hand.

[Spatech_tuo]

No offense intended to your "experts" but... .   Since TUO and NJDave have already weighed in, you might want to consider a PM to Chas, Pkud and Stuart.  They aren't posting as much as they used to, but they always seem willing (and able to lend a hand.

Upon further review, are they "loud" as in they are struggling to get enough air to supply the jets? Sometimes they will almost "whistle" due to the fact that they just can't get enough air through the supply line (the check valve can be restrictive). If that's the case you may want to "T" off at the supply (with a check valve) to allow a greater volume of air to be drawn. It all depends on whether the noise is at the inlet to the air valve or at the jets themselves. Just a thought.

[drewstar]

No offense intended to your "experts" but... .

Don't confuse "posts a lot" as equal to "Expert".

It just means I have a big mouth and a lot of free time.

[Spatech_tuo]

It just means I have a big mouth and a lot of free time.

Don't kid yourself, that is a lost art!

[st18901]

Upon further review, are they "loud" as in they are struggling to get enough air to supply the jets? Sometimes they will almost "whistle" due to the fact that they just can't get enough air through the supply line (the check valve can be restrictive).

No, they aren't whistling... they sound like jet engines. I think it's just the nature of them and the fact that the filter area is like a trumpet in the direction of the water makes it a very, um, pointed sound.

I'm toying with the idea of making a filter front and bringing the front down to th water. With a couple air holes, there should be no problem of air constriction, and then the sound would be baffled back.  Additionally, I'm looking into water proof, sound proofing material that with which I could line the inside of the filter area.

Meanwhile, I AM enjoying the tub, every night, noise or no.  

[st18901]

I'm adding this only so that it might be found by some other person in the future with a similar problem... I don't think i'm solving anyone's problems here but my own.

I solved my venturi noise problem!
Out of a regular household sponge, I cut some new "air filters", which I put over the venturi vent. It quieted the noise right down with no decrease in air to the water. I'm guessing that these existed long ago and rotted out. I'm not sure how they will behave when wet, but it's a cheap fix - so - no biggie. Also, I used a pink sponge so that if/when it begins to break down, I'll plainly see the bits in the water.

Now, the tub has really quieted down. My next mission is to quiet the motor noise by reducing vibration in any way possible.

[NJDave]

Hi st18901,
I'm glad the sponges worked for you, that was the spongy grey or black material that I was speaking about. Your old sponges probably just wore away or fell apart. That is why they became louder. Your air controls are old, that is why they have the sponges and not the ball check valve or rubber check, like more recent styles. Thanks, for sharing your fix, hopefully it will help someone in the future with older air venturis. Dave.

[drewstar]

That's great. I hope the sponges hold up for you.  I am intrigued by your proejcts, so I hope you keep posting.

What are the plans for the motor? Mount rubber pads under the mounts?

[Spatech_tuo]

Great spa detective work. After seeing the work you did on your spa it is truly "sponge worthy".