Silencer for air pump

[The Bear]

Not really sure where best to post this.

I need to either buy or make something that can be used to silence an air pump. The pump pumps air into my pond to aerate it as it has negligible other moving water. I've just installed this as the old one was beyond economical repair. The pump has a manifold, one outlet goes to the air brick in the pond and the other outlet is cranked open about a third and it is this second outlet that is causing all the noise in the form of a loud hiss. I can silence the noise by closing this outlet but I can't do that for 2 reasons. Firstly if I do that too much air goes in the pond causing it to "boil". Secondly if the air brick starts to clog it gives the air somewhere to go preventing overheating and damage.

So I need to leave it open but silence it. The pond is 30 metres from the back door and I can hear it very clearly soon as I open the back door. I know with Camvac extractors people advocate hiding the outlet to muffle the noise but theres no where to do that with this.

Any ideas of how to silence it. Oh and it needs to be water proof

Help

Mark

 

[DrPhill]

I have no direct experience, but can you attach a bit of tube to the extra output? If so try leading this tube into a decorative pile of rocks (fist sized?). I bet that would attenuate the noise without too much risk of blockage.

Or point the tube at the wind chimes.

 

[Myfordman]

Feed the excess back into the air intake.

 

[Grahamshed]

Is the second lot of air coming directly from the air pump or do you have some tubing on it ? The main way we Camvac owners quieten them down is by having a tube on the exhaust. This provides the main benefit and hiding the outlet end somewhere sort of tops it off

 

[bugbear]

Something like a microphone sock?

BugBear

 

[SurreyHills]

How about a pump silencer, available in various thread sizes
sintered silencer

 

[doorframe]

Get a second air brick and supply it with your excess air. You can never have too much air going into the pond. And lots of smaller bubbles oxygenates better than a few big bubbles.

 

[MMUK]

Personally I'd fit a tap to the air stone line and use that to restrict flow and close off the other manifold tap. Any excess air produced will be dispersed through the built in exhaust silencer in the pump.

 

[The Bear]

Thanks for the answers guys

At the moment the manifold is more or less plugged into the pumps output and the manifold in turn has 2 taps/outlets. One goes to the air brick. The other has no tube and I think the first thing to do is get a tube on the and see if this reduces the noise on its own. After that I'll try your suggestions to muffle it further.

Myfordman - The outlet cant be fed back to the intake because of the cover over it that protects it from the elements.

Doorframe - I don't want a second air brick for aesthetic reasons, don't want it looking like a bubbling cauldron - sorry.

MMUK - The air brick airline has a tap. I'm not aware the pump exhausts air anywhere than through the main outlet. If I close the other tap and the brick starts to block the air has nowhere to go risking the pump overheating and burning out - but I may have misunderstood you?

Surrey Hills - Can you tell me how I use what you have linked to, is it just a case of putting it on the end of the line? Any idea how much reduction in noise I'm likely to get?

Thanks all for the suggestions, really appreciate your time. I'm still waiting for the neighbours to ask me if I've got a gas leak!

Mark

 

[SteveF]

would a pipe connected to a funnel quieten it a bit?

 

[Spindle]

Hi

Does the pump not have a means of regulating it's output? It seems all you are doing at the moment is bleeding off excess flow - it would be better if you could reduce the flow and dispense with the bleed.

Regards Mick

 

[The Bear]

Mick, no, all (in my price bracket) pond/cess pit aerators have a fixed output rate.
This is a slightly higher output than my old pump, which I had to buy to get the benefit of auto cut off, which I wanted as my old one eventually shook itself to pieces because there was nowhere for the air to go if the airbrick got restricted.

You could argue why have the bleed if i have the auto cut off now? I suppose the belt and braces effect, but i also still need to bleed some air as sending everything to the pond is too much disturbance to the water, I just need to reduce the noise.

Mark

 

[Steve Jones]

Mark

Don't close off the other manifold tap totally (as suggested above) as it creates pressure within the pump and puts too much wear on the diaphragm, you will be forever replacing the internals.

Been there done that on as they say on a Hi Blow HP80

HTH

Steve

 

[The Bear]

Steve, been there too, hence this set up. The second tap and bleed has to stay.

Mark