OK, so I’d been on the road a few days. Time to get the ‘road grime’ off, so I hit the shower for a ‘quick wash’.
I’d been doing “Efficiency Showers” in Orlando as first thing in the morning, time is dear. Similarly, after a load of ‘Push’ on the road, you just want an ‘Efficiency Shower’ to get the dirt off as you REALLY just want sleep…
So I took a long shower.
The Low Flow Problem
In Orlando, I’d gotten used to the ‘regular flow’ (or ‘high flow’) showers. Nice. Fast. Without the slow adjustment of showers at progressively more restrictive places as I crossed the country (being I was ‘all drive, no stop’) I had a ‘reentry shock’ here in Kalifornia. The Low Flow Shower Head, mandated by local laws.
So I soaped up, and began to rinse. And rinse. And rinse.
Plenty of time to contemplate “Why?”. Why was it taking so long?
I think it is the reality of physical chemistry.
A Body of Soap
A person has a fixed surface area. It has a fixed amount of dirt and oils on it for any given shower event. This requires a fixed (though you can use excess) amount of soap and water to get the hydrophobic ends of the soap molecules dissolved into the oil film layer. The lower the flow rate, the longer it takes to get enough soap and water on. I’d not noticed the added time from the low flow on the ‘soap up’ all that much, probably as it’s the first step and fairly fast any way. You only need enough water to dissolve some soap off the bar and spread it around. A little slower, but even 1 gallon is enough, so we’re in the fractional minutes range for any flow rate over 1 gpm.
Rinsing is another matter. Now you must make an emulsion out of that oil/soap film and disperse it into an excess of water. That takes more water and a fair amount of turbulence. The formation of an emulsion takes the hydrophilic ends of the soap and gets them entangled in a small water droplet, that then physically pulls the soap and the oil film attached to the other end off of your skin. That takes more pressure, flow, time, and water.
I rinsed. And rinsed. And rinsed.
Eventually I was clean. But the length of time needed was far longer than in the high flow showers I’d been taking.
Now I’ve not had time to ‘do the math’. There may yet be some actual ‘water savings’ in the process. BUT… It is at the cost of human time. My time is far more valuable than a gallon or three of water. I also have to wonder just how much the low flow also means ‘less clean’. I do feel like I never did quite get all the soap film off. Like I gave up too soon.
I’m fairly sure that the Low Flow idea is sold based on a direct volume / time comparison. It needs a “volume to get the same amount of clean” comparison instead; and an adjustment for “$ worth of labor / time wasted” per cleaning. Basically, the math of the present justification is wrong.
A simple “what do I feel about it” says that the bias in the Low Flow mandate in California is way too far the wrong way. Next time I’m out of state I think I’m going to pick up a Florida Shower Head ( or maybe a Nevada if they are normal sized…)
In the end, I think that physical chemistry mandates that at some point you end up spending more time for the same benefit, but not saving any water. IMHO, that point is at about 2 x the mandated water flow rate in California.