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- Hacker News
- This assumes a fixed jet injection/intake vector... It's a floppy assumption at best, shaky at worst.by Eridanus2
- I was in a Costco one, and the men's room urinal was a trough, a strainless steel trough! I thought it was 'cool'.
What they need to do with urinal design is to make one that can catch the wide-spray of someone who sports a PA.
I worked as a temp once in a stae government building. It didn't have enough bathrooms. The toilets were of the type that drained/fastened to the wall instead of the floor. One day, someone big sat down and broke it. There was an angry announcement on the rarely-used building-wide speaker. Nobody owned-up to it.
by stevetron - I've seen plenty of stainless steel trough urinals in the pubs and clubs in the UK, and I'm now aware this sentence reads a bit funny.by sph
- I really like the inverted version, where it's almost guaranteed to splash yourself as a deterrent.by ahoka
- > The “urine-no,” a hostile antiurination surfaceby qingcharles
- There are historical examples of this in some alleys in central London (https://www.exploringgb.co.uk/blog/9th-century-urine-deflect...).
I remember being unpleasantly surprised by one after a particularly heavy New Year's as a student.
by henryoz - I'm honestly passionate about this topic. For a while, around the time that urinals started to appear without water, I dealt with some serious splashback issues. I forget when I started aiming for the back of the urinal. I'm assuming that's the deflection angle the paper discusses. At one point I realized, I was sometimes getting some pretty bad splashback. Perhaps because I stood close to the urinal. So I asked a colleague. He said he aims for the hole, and was confused why anyone would piss on the back of the urinal. I started doing that -- problem solved. I am for a direct hit, every time. The problem is that some urinals have a protector over the hole to prevent really smart people and children from putting paper towels in there. That thing is dome shaped, and multiplexes the stream like a lawn sprinker.
All of this, would not be necessary, if there were water at the bottom of the urinal.
by readme - Even if a urinal doesn't splash, there's usually (always?) a decent amount of fine droplets that eject out from the stream since the flow is rather turbulent. On top of that, the fleshy opening is never completely stable.
What we really need is laminar flow!
by ravenstine - A custom 3D-printed user-matched disposable nozzle, perhaps? One could carry a handful in his pocket and don before the act.by gattr
- Laminar flow from the man?
I've seen youtubers achieve laminar flow by filling garden hoses with aligned drinking straws. Perhaps... there's an idea here...?
by Rendello - No amount of engineering can solve the problem that no matter how much you jiggle, you shake, or you dance, the very last drop always falls in your pants.by geekamongus
- Solution to that problem would deserve a real Noble, not just an iG-one.by wafflemaker
- I stopped having that problem when I started taking a single square of toilet paper, folding it into a quarter square and using it to dab the tip a few times to get the last bit of liquid out. There's enough space to dab a few times with a different spot on the paper and folding it makes it thick enough to not have liquid go all the way thru. Since I started doing that I don't get the post restroom drip. Not really useful for a urinal, but it does work.by buck746
- Sometimes i am using an urinal and i feel like no engineers were involved in the design. Glad to see someone is actually approaching this with proper science.
There is more to it than the splashback tho. Sometimes it seems that the surfaces that already have splashes on them are not angled properly to lead the water to the drain. This seems to create need to have sharp edge/lip rather than round one, which might be tricky to make resilient in porcelain. But the rounded lip certainly allows for droplet flow towards the user rather than the drain hole.
by harvie - Really old urinals don't splash back.
The engineers have spent the last 50yr trying to reduce water usage and material usage without making the product "noticeably" worse. Of course you add up 50yr of "it's 99% as good on our test, nobody will notice" and you get some degradation.
- My pet peeve about urinals has to do with the way the separating walls are usually installed. It's systematically too low, as if their goal was to prevent splashing between each station instead of their role of visual privacy.by abyssin
- Ig nobel prizes were just a few days ago:
https://improbable.com/ig/winners/#ig2026
Edit: The splash free urinal was the winner for physics!
I once joked that these do more for science than Nobel prizes. Now I don't think it's a joke: "wacky but interesting" awards are more important for the advancement of science than "everyone agrees this these people should be even more famous" awards.
by dguest - I wonder whether a “Ig Nobel Price Winner” sticker would provide marketing benefits for an urinal.by microtherion
- Meet the Ig Nobel Prize Winners - https://news.ycombinator.com/item?id=49576611 - Sept 2026 (42 comments)by dang
- I remember being annoyed by splash back in sixth grade. I mocked up an alternative design (essentially, a urinal that tilted away from you), and emailed some friends. They never responded, and I never followed up.
Looking back I feel sad - that's the kind of curiosity to nurture in a kid. But peers are rarely the best group, it would've been better to tell my parents or the right kind of teacher. My friends also could've said something: " I don't know what to do about this but you should tell ms blah blah blah", in a serious way not mocking way.
I'm glad someone else has finally looked at this sticky situation
by xivzgrev - I mean you're sad about a hypothetical. Why not consider the alternative where even your parents and teachers will probably not care because who wants to hear about a splash free uniral design from a kid in sixth grade. Like if some kid walked up to me with that, I would ignore them too sorry.by altmanaltman
- You would have been an excellent splash sputter scientist.
> I'm glad someone else has finally looked at this sticky situation
Wait ... your splash variants are sticky???
by shevy-java - Global sustainability and accessibility seems a bit grandiose lol. It’s just a urinal after all. That being said, it’s been 4 years since Waterloo first determined this and it’s still unavailable to purchase. I’ve been patiently waiting for one to install in my shop but it seems like it’s not all that important for the globe if it’s still unavailable 4 years later.by d-e-r-e-k
- There are a lot of reasons why something could get picked up, and sustainability is very low on the list. The manufacturers don't care; they get paid the same regardless of the amount of splashback. Most businesses won't care unless it significantly reduces maintenance overhead, and that's only going to happen if splashed urine is the determining factor in how frequently a bathroom gets cleaned. (As opposed to paper towels littering the floor, supplies running out, or the various disgusting things that happen in stalls.) Even if it were the determining factor, there would likely be pushback when people realize that better urinals lead to less frequent cleanings, and I wouldn't want to be the one having to justify the switch to people. And of course, if you already have a urinal, nobody's eager to buy a new one, and nobody's eager to discuss this particular topic.
The way I would see this happening is if users insist on it. And we likely won't until we experience one of these in real life, which makes it a chicken and egg problem.
There's also the argument that splash mats are a cheaper and even superior approach. That argument is unconvincing to me, because the ones I have experienced have been mostly ineffective, but it sounds like others' experience has been better. Maybe here in the US we just don't have very good ones? As a country, we've always been pretty bad at anything that seems gross. (Not that it's all that different in the rest of the West.) We have this naive faith in the ability of dry toilet paper to clean that which it can not, and disgust at alternative approaches that actually work. But that's a different topic. (Specifically, solids not liquids!)
by sfink - Same attitude that prevents the urinal manufacturers from switching I reckon
- I would love to see some Nautilus style urinals because--as a self-interested adult--splashback also hits me if the angle is bad enough. Sometimes I even use the stalls to avoid those porcelain tricksters entirely.by zdc1
- There are performant urinals in the market and have been for many years.
Talk to a local mechanical engineer who does plumbing design for recommendations that are available in your market and their probable cost.
If you are getting noticeable splashback, you have a very poorly designed urinal. The kind that gets architects angry calls from clients.
——
I used to work in architecture.
by brudgers - Things we take for granted, like washing hands, were pivotal in reducing illness in hospitals.
If 50% of the population walk out of a public bathroom without tracking urine on their feet or anything else that touched the floor and custodians have 99% less bodily fluids to deal with, that seems like positive progress. Maybe it will move the needle in ways that are unexpected.
by jonhohle - Design through physics and differential equations.
This paper is Ig® Nobel Physics Prize Winner 2026 https://improbable.com/ig/winners/
by u1hcw9nx - The recent introduction, in the UK at least, of splash-back reducing urinal … mats (?) has basically solved the problem in my opinion. They’re a disposable (but not single use…) plastic freshening insert with loads of short rubber strands, closely packed.
You can pee on one of these mats and the stream almost aerates itself on impact and you get basically no splashback, I guess with a similar mechanism to how an aerating tap produces a stream of water that doesn’t splash off whatever it hits.
by danw1979