So water is coming out white from my faucet as it normally happens after service interruptions. No drama, it is just little air bubbles that go up and away in no time. The kids just love watching it.
Got me thinking, though. There is an aerator in my faucet (as in every other faucet that I am aware of). Shouldn’t I be seeing the same bubbles every day? Or coming from the other side, shouldn’t the aerator mix and do away with these bubbles?
What’s the difference? I have a hunch that it has to do with the size of the bubbles but I cannot get past that to where it all clicks together. Anyone?
if there is air in the pipes it will come out in spurts and interrupt the stream and have bubbles in the stream. these are large pockets of air in the water flow.
the aerator splits the stream at the faucet exit and mixes it with air from the room.
Not what I am asking. I know about the hammering of large bubbles and the humming noise and all that.
I am asking about when the water comes out white with tiny bubbles. Why isn’t the aerator either always creating that effect or cancelling it when present?.
I’m pretty sure that “white water” is caused by dissolved air in the water. When the water system is worked on, some air gets trapped. When the water is turned on at the main, the air gets dissolved in the water, and is released when the pressure is reduced (when you turn on the tap). The Aerator on your faucet does something completely different - it just mixes (entrains) air in the water so that the water doesn’t come out in a solid stream.
when you have air in your plumbing it would get pushed out evenly going up vertically, in horizontal runs the water would run ahead of the air somewhat and create pockets of air in the water stream. towards the end of purging the pipe these pockets of air can get to be small.
the aerator breaks the stream into tiny streams and drops which the room air goes between. it affects the world on your side of the faucet. actually not true, it also acts as a strainer capturing solid particles in the water. it is good to clean out occasionally to keep full flow and to take off when purging the pipes of air because that action can put solids into the stream.
Yes. The air bubbles your aerator makes are much larger than the air bubbles that form from the air dissolved in your water. The larger bubbles rise to the surface more quickly.
How is the water pressure at that tap compared to the rest of the house? Is it just the cold water, just the hot water or both? Have you tried taking the aerator off and seeing what happens?
When water flows past a constriction under excessive pressure, cavitation can result. I suspect that is your case.
I think you’re asking why you don’t see the same consistency of bubbles, and shouldn’t the aerator consistently aerate?
If I’m reading your q correctly, I think it has to do with the flow and speed. I think aerators have gaps above the screen near the top of the cylinder. When water is flowing quickly, air is pulled in through these gaps by Bernoulli effect. The screen then disperses the air into small bubbles.
Running the faucet at different pressures will affect how much air is pulled into the aerator for aerating. Different faucets will have different flow rates (and different aerators), and even the same faucet at the same setting will have different flow rates based on line pressure fluctuations.
So you’ll notice that low flow rates will have no aeration (low flow will have a low Bernoulli effect).
So I am gathering that these tiny bubbles didn’t come to my tap in the form of bubbles but as dissolved air in the water that came out of solution (?) when they went from the high pressure at the pipe to the lower atmospheric pressure. Right?
When it happens it happens in all the house. You notice it more in the kitchen because that’s where you normally fill containers with it instead of seeing it run as you do in the bathroom sink or the shower, I presume.
glilly, that makes sense. When I open the water just a little bit it does come as a “solid” stream not aerated.
The bubbles don’t come from dissolved air coming out of solution. It’s just air being pulled in from the sides about an 1/8 inch above the screen, then dispersed into smaller bubbles by the screen.
I woudn’t know about where the bubbles come from, but (as a plumber) I have installed hundreds of boilers; when you fill (or refill) a 200 liter boiler with cold water (water is distributed here at 3 to 7 bars) the flow at the tap is “foamy” for several hours, then goes back to normal. I have had this “first draft” off a new heater tested (for a client with babies) in case this would be some rinsing or other residue in the boiler, with negative result ( the control was identical). I have since supposed that it was air trapped in the water during the filling process.