MIMF

Ever since I moved to northeastern California where the wind blows hard and Bernoulli's principle acts on my toilets, I've been meaning to do this. A storm came in today, so I finally did it. I used to have a nice anemometer, but the dog ate it. Now I have another which is not so nice, and used it to (not very accurately) calibrate this. Highest speed today was only about 50mph - I've clocked up to 114mph in the past causing some minor damage.
The gauge was hard to read, so I added some organic yellow dye to help out.

I........ that......... yeah.

I'm just glad you didn't decide to add ballast to the system.

Already Peter you've made my weekend!

b.t.w. "wind" in Dutch means besides "wind" also "fart" so I can think of multiple situations where it can come in handy...

I'm not quite clear why the winds are causing your toilet water level to lower. Is it that the wind across the plumbing vent pipe causes a vacuum in the vent, drawing the water from the trap??

Bryan Bear wrote:I'm just glad you didn't decide to add ballast to the system.

Might help calm some of the sloshing.

Hans Bezemer wrote:
b.t.w. "wind" in Dutch means besides "wind" also "fart" so I can think of multiple situations where it can come in handy...

Yes Hans, here in the US we "break wind" also, though it would have to be quite a significant flatus to drive water from the toilet bowl.

Bill Raymond wrote:I'm not quite clear why the winds are causing your toilet water level to lower. Is it that the wind across the plumbing vent pipe causes a vacuum in the vent, drawing the water from the trap??

Correct - Bernoulli's principle. And if the wind is high enough, it pulls some of the water out of the trap and into the sewer pipe, so the level stays low until the next time it is replenished.
http://www.leancrew.com/all-this/2011/0 ... ur-toilet/

So if the winds gets strong enough you'd end up with an atomized spray out the vent stack? Talk about HVLP, remind me to stay in when that happens.

David, I doubt very much that the the vacuum created by the wind is strong enough to pull the water completely up the vent stack and create any spray. More likely, the water is pulled from the trap and drops into the waste line. There is probably more spray in the bathroom when flushing the toilet than there is from the vent. Best to put the seat down before flushing!

Since we're talking seriously now, I've seen this happen, but thought it was an inside vs. outside air pressure thing.

David King wrote:So if the winds gets strong enough you'd end up with an atomized spray out the vent stack? Talk about HVLP, remind me to stay in when that happens.

I think if there were a wind that strong, there would no longer be a vent stack or a toilet present.

Toilet humor! Gotta love it!

Jason, it IS an inside/outside pressure differential that causes this: The Bernoulli effect of the wind across the vent stack lowers the pressure in the stack, while the inside pressure remains constant, causing the water to be pulled from the trap and drained down the waste line.

Right, I guess if you think of it like a straw: when you suck on it, you're lowering the pressure in your mouth, while atmospheric pressure on the surface of the beverage is now higher. How 'bout that. Science is cool.

I've seen a lot of things in my years here on the MIMF. This is a new one! Ha ha.

Yeah, Mark, this is an odd one. We have some pretty strong winds here in the foothills outside of Red Bluff CA, too, but have never experienced changes in water level in the toilets.

Bill Raymond wrote:Yeah, Mark, this is an odd one. We have some pretty strong winds here in the foothills outside of Red Bluff CA, too, but have never experienced changes in water level in the toilets.

Bill, I live about 80 miles (as the wind blows) due east of you (Janesville) on the west side of a hill. The wind apparently picks up a little velocity from your house to mine as it goes over the mountains. My water is from a well, so a stained mineral ring forms in the toilet pretty quickly at the normal air/water interface, and it can be pretty apparent when the level changes.

Peter, I never had well water until we moved up here. It's a refreshing change from city water, but it does leave a bad ring of mineral deposits. If I could, I'd like to use the rainwater that we collect from the roofs of the garage, shop and house for washing and in the toilets, but it would require an impossible re-plumbing job. I'm planning to use rainwater in the evaporative coolers though, and at least we aren't emptying the well for the plants anymore.

I photographed this device recently, designed for high wind/ tornado warnings.

Peter should contact the maker of that tornado gauge. One of the byproducts of producing such instruments is the very same as Peter's organic yellow dye.