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jack4566 · 09-11-2020, 22:26

Looking at water systems it looks like people use filters or chemical dilution for clean drinking water. But UVC LEDs are getting cheaper so does anyone make an LED based UVC sanitizer?

If not, would this be a product you would buy? I have the means of production to make a product like this.
Say it was a 1in round though tank device that runs of 12VDC for a few minutes every hour.

sailormed · 10-11-2020, 01:31

There are other contaminants then bacteria, would your device eliminate those as well? Or do you still need a filter to eliminate those.
Second question, what is the energy balance of the devigce?

**tkeithlu** · 10-11-2020, 04:40

I would guess that it's a pretty small market, good as it sounds. It may be limited to people who suspect that their water source is contaminated and don't drop a little bleach into the tank to take care of that possibility. Eight drops per gallon will clean up any physically clear water. A filter takes out the other stuff. If in doubt we just use the water maker, which does a better job than our home municipality.

How would you make sure that the light is under the water?

**a64pilot** · 10-11-2020, 05:26

won’t work, water absorbs UV in a very short distance, so it would take many light sources.
You could in theory disinfect an empty tank though, still need a source on either side of any baffles though.

jeanathon · 10-11-2020, 05:37

Another problem would be that it would degrade plastic based tanks.

Singularity · 10-11-2020, 05:43

One can buy a UV ~sanitizer that zaps water flowing in effectively small tubing before the tap, but what's the point of ignoring all the old tried/true/cheap ways of doing things.

sailorboy1 · 10-11-2020, 06:00

The problem is that does nothing for growth in the tanks and piping

**GordMay** · 10-11-2020, 06:12

A UV water purifier does NOT remove particles, nor remove bad tastes and odors from water, so, you’ll still require some sort of pre-filtration (5-10 micron), to remove particulates (turbidity), to prevent pathogenic microorganisms from hiding behind loose particles.
Also, what a64pilot said.

Mplight · 10-11-2020, 10:46

Actually there are LED UV-C disinfection systems used for water systems, typically for large scale disinfection- think municipalities. They operate at 275 nm typically, but other wave lengths are available with different spices such as Low pressure mercury vapor
And Excimer technologies. they are relatively large systems and there are specific doses needed to disinfect water system for Viruses and Bacteria. Also, as mentioned above UV-C (UV-A and UV-B) do degrade plastics and other materials.

AndyEss · 10-11-2020, 11:34

I like your idea, but then again, I built LED based UV systems for a different application.
I think I would make it a point of use device, say the cold water spigot in the galley. You would have to keep the price (and energy use) point pretty low to compete with the “just add bleach” and carbon block filtration competition. My boat came with a non-LED UV sterilizer in the water system, but I have yet to wire in the relay to sync it to the fresh water pressure pump. The original system was either on or off, which is an energy waster or doesn’t get used. I’ll probably get around to replacing the mercury bulb UV source one of these days with the UV LED’s I have as surplus from my other projects.
Intestinal bugs are never fun, so a belt and suspenders approach is reasonable to me.

caffel · 10-11-2020, 11:43

I have experimented recently w UVC lights (tubes) and several are 12v DC.
Mount one of these within a shiny tube along with a glass tube that carries the potable water and you have a germ killer that's about 3" dia and a foot long requiring about an amp of power. Put a conventional water filter on the intake side of it and recirculate to the tanks and you have a very good broad based solution for under $75. Alternatively, take the UVC tube itself and build it into the removable tank cover.
UVC rays are bad for your eyes and skin but not so much for plastic or plumbing fittings.
https://www.amazon.com/CNZ-Watts-Ger.../dp/B007CM5FPO

AndyEss · 10-11-2020, 11:49

Quote:

Originally Posted by caffel

I have experimented recently w UVC lights (tubes) and several are 12v DC.
Mount one of these within a shiny tube along with a glass tube that carries the potable water and you have a germ killer that's about 3" dia and a foot long requiring about an amp of power. Put a conventional water filter on the intake side of it and recirculate to the tanks and you have a very good broad based solution for under $75. Alternatively, take the UVC tube itself and build it into the removable tank cover.
UVC rays are bad for your eyes and skin but not so much for plastic or plumbing fittings.
https://www.amazon.com/CNZ-Watts-Ger.../dp/B007CM5FPO

You need to make sure your glass tube that carries the potable water is UV transparent. I remember that borosilicate glass is UV transparent. I bet most clear plastic tubing blocks UV (which means you achieve nothing) and also will degrade and leak eventually.

sv_pelagia · 10-11-2020, 12:03

check out
https://waterfixercompany.com/

Cheechako · 10-11-2020, 12:10

I have had a UV undersink unit. The water just flows through them and the light kills stuff.
The UV bulbs are somewhat expensive. They require power. The water ends up hot when you turn the tap on, so not something you feel like drinking. If they made these LED based I suppose that would be a big step up. But does LED light actually kill bacteria?

I went to an undersink RO unit for drinking/cooking water, no pump, no electricity required, just works off water pressure. Really doesn't take much room and they are cheap. But flow is slow for general use. For drinking and cooking it's fine.