Speed of bath draining

[Harry Bloomfield]

All impressions, rather than timed.....

I've often wondered if sinks and baths might drain faster, were it not for the fact that once the plug is removed, the water begins to swirl, as it progresses down the plug hole - drawing in air, and sometimes even more air via the overflow....

Whether by luck, or design, our bath has always been reasonably quick to drain, but always accompanied by lots of swirling, and air sucked in at the overflow - when fitted with a normal, bath sized plug. I recently needed to swap the plug, so decided to fit a pop-up type. The pop-up, at a guess restrict the outlet area to around 50%, so I anticipated it might double the time it takes to drain the bath. In fact it appears to drain (at least initially) somewhat quicker than it did before. The water no longer swirls as it nears the plug hole, the suction of air via the overflow and glucking has stopped. Only once the level in the bath has reduced to the final inch or two, do it appear to drain slower.

My conclusion - Obviously, the swirling, flings the water out and away from the plug hole, slowing the flow.

 

[Odds]

You have way too much time on your hands.

Get a stopwatch.

 

[freddiemercurystwin]

Perhaps the slight alteration has turned it into Siphonic Drainage? Google it - it's a thing.

 

[Odds]

Siphonic Drainage - is that where you lose the will to live when you time the bathwater pouring away?

 

[Harry Bloomfield]

Perhaps the slight alteration has turned it into Siphonic Drainage? Google it - it's a thing.

Thanks, that was trying to explain, without knowing the words.

 

[Harry Bloomfield]

You have way too much time on your hands.

Get a stopwatch.

Just something I've always possessed - an enquiring mind. I may get around to actually timing it, over the next two baths..

 

[Odds]

I'm a gog with anticipation.

 

[Trazor]

Just something I've always possessed - an enquiring mind. I may get around to actually timing it, over the next two baths..

Come on , we can't wait 6 months.

 

[Harry Bloomfield]

Perhaps the slight alteration has turned it into Siphonic Drainage? Google it - it's a thing.

Mmm, an interesting theory and something I've wondered about for a while - the swirl or whirlpool effect slowing the drainage down. An idea I used to think might work, was baffles around the plug hole, to defeat the swirl effect. The way the pop-up seems to work, is by restricting the air being drawn in down the middle of the flow, increasing the vacuum effect, and the speed of the flow, despite restricting the overall cross-section.

I would be concerned about using siphonic drainage technics on gutters, because, the narrowed openings, increase the risks of blockages, from the likes of leaf debris.

On a different note - when washing and rinsing wine bottles, before I refill.... I find the washing and rinsing works much better with just a small amount of water in them, which is swirled round, than a larger fill of water. The final rinse, works best with an inch in the bottom, spun, then inverted to continue spinning as it drains.

 

[Deleted member 294929]

Just cleaned my bath trap out.

With 3 girls and 2 dogs I have to do this 3-4 times a year.

 

[securespark]

I find a bottle of water empties quicker if you give it a swirl first.

Edit:
Sorry, Harry...I did not notice your earlier post!

 

[Harry Bloomfield]

I find a bottle of water empties quicker if you give it a swirl first.

Yep, the swirl causes the liquid to flow down the outside, and air to rise to replace it in centre. Just tipping a bottle up, causes it to cluck - some water out, some air in, stop go.

 

[motorbiking]

Just cleaned my bath trap out.

With 3 girls and 2 dogs I have to do this 3-4 times a year.

When seeing me pull half a tonne of long blonde hair out of the trap, the other half said "is there anything I can do?" Shave your head, was my reply.

 

[THFC]

Just something I've always possessed - an enquiring mind. I may get around to actually timing it, over the next two baths..

You must be an absolute hoot at parties

 

[blup]

All impressions, rather than timed.....

I've often wondered if sinks and baths might drain faster, were it not for the fact that once the plug is removed, the water begins to swirl, as it progresses down the plug hole - drawing in air, and sometimes even more air via the overflow....

Whether by luck, or design, our bath has always been reasonably quick to drain, but always accompanied by lots of swirling, and air sucked in at the overflow - when fitted with a normal, bath sized plug. I recently needed to swap the plug, so decided to fit a pop-up type. The pop-up, at a guess restrict the outlet area to around 50%, so I anticipated it might double the time it takes to drain the bath. In fact it appears to drain (at least initially) somewhat quicker than it did before. The water no longer swirls as it nears the plug hole, the suction of air via the overflow and glucking has stopped. Only once the level in the bath has reduced to the final inch or two, do it appear to drain slower.

My conclusion - Obviously, the swirling, flings the water out and away from the plug hole, slowing the flow.

Have fitted a pop up wate on a bath and drains very quickly but anti siphon trap and good straight short pipe run helps as well