Why aren't there LED UV Sterilizers

[dangros]

Is there a reason there are no LED based UV filters?
Changing out bulbs sucks in 2016

 

[jjwukasch]

There is this...

http://www.fish-street.com/yee_2w_led_dc_uv_sterilizer

 

[dangros]

Oh I could just do my whole tank with that one!

 

[Big E]

This is taken from an EPA UV guide I have in my files----


2.2.1 Nature of UV Light


UV light is the region of the electromagnetic spectrum that lies between X-rays and
visible light (Figure 2.1). The UV spectrum is divided into four regions: vacuum UV [100 to 200
nanometers (nm)]; UV-C (200 to 280 nm); UV-B (280 to 315 nm); and UV-A (315 to 400 nm)
(Meulemans 1986). UV disinfection primarily occurs due to the germicidal action of UV-B and
UV-C light on microorganisms. The germicidal action of UV-A light is small relative to UV-B
light and UV-C light; therefore, very long exposure times are necessary for UV-A light to be
effective as a disinfectant. Although light in the vacuum UV range can disinfect microorganisms
(Munakata et al. 1991), vacuum UV light is impractical for water disinfection applications
because it rapidly dissipates in water over very short distances. For the purposes of this manual,
the practical germicidal wavelength for UV light is defined as the range between 200 and 300
nm.
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I don't think there any LEDs produced that can hit these levels or even come close to the consistency/performance of the bulbs.

I would think an independent LED manufacturer would have to develop and produce a specific led for this application. It's probably not a very cost effective or money making endeavor right now.

 

[cb684]

This is taken from an EPA UV guide I have in my files----


2.2.1 Nature of UV Light


UV light is the region of the electromagnetic spectrum that lies between X-rays and
visible light (Figure 2.1). The UV spectrum is divided into four regions: vacuum UV [100 to 200
nanometers (nm)]; UV-C (200 to 280 nm); UV-B (280 to 315 nm); and UV-A (315 to 400 nm)
(Meulemans 1986). UV disinfection primarily occurs due to the germicidal action of UV-B and
UV-C light on microorganisms. The germicidal action of UV-A light is small relative to UV-B
light and UV-C light; therefore, very long exposure times are necessary for UV-A light to be
effective as a disinfectant. Although light in the vacuum UV range can disinfect microorganisms
(Munakata et al. 1991), vacuum UV light is impractical for water disinfection applications
because it rapidly dissipates in water over very short distances. For the purposes of this manual,
the practical germicidal wavelength for UV light is defined as the range between 200 and 300
nm.
----------------------------------------------------------------

I don't think there any LEDs produced that can hit these levels or even come close to the consistency/performance of the bulbs.

I would think an independent LED manufacturer would have to develop and produce a specific led for this application. It's probably not a very cost effective or money making endeavor right now.

http://www.hexatechinc.com/uv-c-led.html

I believe it is a matter of time.

Edit: http://www.lasercomponents.com/uk/product/uvb-uvc-leds-200-315-nm/

2nd Edit
If not already exists, it is close...
http://www.s-et.com/water-sterilization-using-uv-leds.pdf

 

[dangros]

I emailed the last one to see if they have anything for our application. I doubt it but it's free to ask

 

[Big E]

That's interesting, thanks for the links. I guess we'll see what transpires in the next 3-5 years & if anything shows up for the hobby level.

 

[cb684]

I found some from Alibaba.com, so it is out there. But the ones I saw were really big and apparently for freshwater (ponds).

 

[mcarroll]

All of the big benefits for LED in freshwater and saltwater lighting is based on the awesome efficacy of the blue LED.

All white LEDs are blue LEDs covered with phosphor.

Other colors of LEDs don't necessarily have the 50,000 hour rated life of the blue LED. I'm sure things have changed some since the last time I read up on it, but UV LEDs were in this category. They also don't have the volume that the blue LED has, so the unit price is higher.

Once you raise the unit price and cut the efficacy, switching to LED doesn't make quite as much sense or at least it's not an automatic decision.

 

[Ryengoth]

To get the same 265nm shortwave UV that a mercury plasma produces, from an LED, is going to take a lot of power from a UV-C LED array. I looked into making a prototype GHA torching stick using 265nm LEDs and the price tag alone on 1 segment board turned me off to the idea of even starting it considering how cheap most reefers are on hardware, despite how much they'll spend on specimens. It would take 3 or 4 segments at $600 a pop to produce enough of a ray of UV-A to kill enough organics in a relatively slow water stream to make it useful. Also, keep in mind that UV-C and anything below like 300nm is going to oxidize(destroy) any kind of long-term lens except for highly polished industrial sapphire.

 

[enaly]

Here is a UVC LED for aquarium on the market.

ENALY OZONATORS

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