UVc LEDs??

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JR.
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UVc LEDs??

Post by JR. » Wed Mar 21, 2018 1:46 pm

I have been messing with UVc light to disrupt unwanted microbes.

I have recently become aware that they make UVc LEDs.... this seems really cool (while only 5% of energy is converted to UV light) still promising.

I did a search and the only LED modules I could find in distribution were crazy expensive $50-$150 ea. I did find some in the $20s but still too much.

I did purchase a UVc CFL with an edison base that is easier than having to come up with a starter for the typical UVC fluorescent. They claim 7K hours which will be better than I generally experience from small fluorescents.

There are tons of cheap LED black lights and finger nail curing lamps, but these are not in the sweet spot (200-300nM) wavelength for trashing biotics.

JR

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mediatechnology
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Re: UVc LEDs??

Post by mediatechnology » Wed Mar 21, 2018 3:36 pm

We put our outdoor plants in the basement over the winter and I use florescent grow lights.
I was harvesting cherry tomatoes in December.

I realize that LED UVc and grow lights are not the same thing but when I priced the TOGLED T8 LED grow lights they were also about $50 a tube.
That may be the going price for specialty wavelength LEDs.

At least for the next 4-6 months.
Then they'll be half that. :lol:

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JR.
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Re: UVc LEDs??

Post by JR. » Wed Mar 21, 2018 3:59 pm

Yup, I'm too early, so price too expensive... I was finding UVc LED chips for $50-150... while black light or finger nail epoxy curing LEDs are dirt cheap. I got a couple UVc CFL lamps (<300nM wavelength) with edison base on order so that will keep me busy for now.

I am rethinking my mold spore killing strategy. I had a small 6W UVc fluorescent tube (with transformer) mounted deep inside my hepa filter, but the mold spores were already filtered out of the air flow by then.... New plan is simple box fan with 16W CFL mounted in the airstream... I will need to shroud the light, and avoid the UVc light since it is bad for human eyeballs.

If I ever step up to a real heat pump heat/cool system, I can mount UVc inside the air box. My cheap in wall unit should run another several years, so no hurry for now.

JR

PS: There is a decent medical market for UVc infection mitigation so prices should come down sooner or later.

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JR.
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Re: UVc LEDs??

Post by JR. » Mon Mar 26, 2018 1:05 pm

The hepa air filter advice suggests replacing the paper filter every 3 years. Since my air cleaners were still using the original filters, I finally replaced them... :roll: The inside of the paper filters were still pure white, but the outer surface was decidedly gray. :o The paper filter has an additional odor/dust filter wrapped around the outside, and it gets loaded up with dust every few weeks, so I clean that with my vacuum cleaner. Vacuum uses hepa level dust filter bags too, so bad stuff gets trapped and removed one way or the other (mold spores are larger than hepa level so easily trapped
in hepa filters).

--------

My 15W CFL bulbs showed up today so I mounted one into a cheap box fan. Not sure what I expect this to do but I will start using it in rooms when I am not using them (bed room during day, main room at night). This would have done more good several years ago, when I still had black mold everywhere. As mold dies off, it shoots out more spores in a desperate survival response, so I expect I have seen the worst of that a few years ago.

Years of elbow grease, low humidity, and hepa air filters have done a lot of good and I can breath easy.

JR

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mediatechnology
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Re: UVc LEDs??

Post by mediatechnology » Mon Mar 26, 2018 4:07 pm

Do you have carpet?
I've pulled it up in every home I've owned.
In the slab floor home we had I slept better the first night.
The air freshness difference was amazing.

Nothing ever comes out of carpet. Nothing.
Every little bit of silt collects underneath and stays there.
In a 20x20 room with carpet that's been down for 10 years you'll easily get a 5 gallon bucket of dirt from underneath the padding.

In 2/3 of the home I had hardwoods underneath and they were OK.
In the slab home, until we replaced the floors, we lived on concrete.
Most areas got tile.
We moved before I was able to stain the living room.
Stained concrete can be really pretty.

You're on pier and beam?

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JR.
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Re: UVc LEDs??

Post by JR. » Mon Mar 26, 2018 5:37 pm

mediatechnology wrote:
Mon Mar 26, 2018 4:07 pm
Do you have carpet?
I've pulled it up in every home I've owned.
In the slab floor home we had I slept better the first night.
The air freshness difference was amazing.
I removed the carpet from my bathroom that was totally trashed by mold from a leaky toilet... mold likes water. I replaced that carpet with a wood floor a bunch of years ago.
Nothing ever comes out of carpet. Nothing.
Every little bit of silt collects underneath and stays there.
In a 20x20 room with carpet that's been down for 10 years you'll easily get a 5 gallon bucket of dirt from underneath the padding.
I have a beater brush vacuum with a dirt finder LED and it's remarkable how long it takes for the LED to turn green sometimes. :roll:

My carpets in the large living area were replaced about 20 years ago when my roof leaked.

I removed the redneck indoor-outdoor carpeted kitchen floor and replaced that with linoleum (vinyl?).

When I got serious about cleaning I literally broke the handle off my old carpet shampooer from fatigue. I replaced it with a serious (better) Bissell big green shampooer that doesn't suck, actually it sucks real good. :lol: I souped it up by blocking 2/3 of the suction intake slit, so it pulls with 3x the suction force of stock and it picks up dirt that much better. In fact it never stops finding dirt, :oops: so after a while I get tired and stop shampooing for the day.

I am inclined to agree, my carpet will never be completely pristine again. In fact I use some anti-bacterial shampoo that keeps it from coming alive and smelling bad from the dampness introduced when shampooing.

My carpet is night and day cleaner now than it was before big green several years ago, but I could keep cleaning it perpetually. My pattern is to spend summer weekends doing yard work, and (cold and dry) winter weekends shampooing. Last winter only allowed a few weekends of serious cleaning so I got the carpets back only to last year's clean level but there is always more to dirt to get up. Of course there's always next winter. :D
In 2/3 of the home I had hardwoods underneath and they were OK.
In the slab home, until we replaced the floors, we lived on concrete.
Most areas got tile.
We moved before I was able to stain the living room.
Stained concrete can be really pretty.

You're on pier and beam?
I guess.... brick/cinder block foundation... empty crawl space, particle board flooring under carpets.

House is not worth redoing the carpets or floors... I did the wood floor in my bathroom and that one small room was enough of a PIA.

I literally had lung congestion from breathing the mold several years ago...it was bad enough I even had trouble sleeping at one point (noise from me wheezing kept me awake), but now no problemo.... 8-) Of course I replaced my bed mattress and cleaned up mold from literally everywhere. Even the insides of my windows were covered with a film of mold. Kind of disgusting (mold loves water so condensation on the single pane glass was hospitable to mold colonization).

Now the low indoor humidity (<50%) and my redneck storm windows fixed that.

JR

PS: I am noticing ozone smell with my new CFL UVc lamp... they claim ozone is only made by shorter wavelength (<200 nM) than than my 250nM UVc lamp, but I don't know how pure that lamp output is so may be making small amounts of ozone... a little ozone is OK. FWIW my old 6W CFL lamps make ozone smell too. Dedicated ozone lamps target 185nM or so. I expect the wavelength has something to do with energizing oxygen molecules to break up O2 and form O3

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Re: UVc LEDs??

Post by mediatechnology » Mon Mar 26, 2018 9:55 pm

My first house was built in 1954 with pier and beam construction and it developed a mold/mildew problem in winter with extreme condensation on and below the windows.
One winter we had perpetual rain and became like living in a terrarium.

I decided that I'd had enough and turned the heat up to something like 85 or 90°F just to burn off moisture.
Running the heat made humidity worse - the complete opposite of what you'd expect.

I knew that the house wasn't originally air conditioned and had been retrofitted for central air.
When they do that they sometimes reverse the flow to make the floor supply vents the return. In this house they had.
The return ducting was underneath the sub-floor.

Somehow, after thinking about it a few minutes I figured out that the heater was sucking in wet basement air.
(I think with a flashlight I could see one of the return boxes rusted out through the vent grate.)
So I went up in the attic and pulled off the side of the plenum so the heater was sucking in attic air.
Not very efficient for heat but it was dryer air.

Within minutes of running the heater drawing attic air the house had completely dried out.
Later that season I abandoned the old return system and did a central return in the hallway.

After applying about 10 gallons of Kilz and repainting the entire house I pulled up the carpet to reveal beautiful Oak hardwood floors in near pristine shape. I had lots of little staples to pull but it was worth it.

And I started sleeping and breathing better immediately.

After that episode it became hardwood, tile or concrete. I banned carpet.

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JR.
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Re: UVc LEDs??... humidity/water

Post by JR. » Tue Mar 27, 2018 10:30 am

This is why I own 3 dehumidifiers (2 serious ones, and one cute peltier based one). I alternate running a dehumidifier in the rooms I am not occupying, so right now I have a dehumidifier running in my bedroom (and my new UVc blaster). The ozone smell is not as bad as I feared, and a little ozone could be OK.

Depending upon the weather I pull several quarts a day of water from my household air daily. I could easily irrigate a small greenhouse from my interior humidity. I don't keep any house plants because that would just add more moisture. Note: when the air conditioner is working hard, the dehumidifiers collect less moisture.

I have hi/lo humidity loggers in bedroom and living area to monitor humidity that I maintain in 40-50% range. This range suppresses mold growth but I have decades of old growth I still haven't completely uncovered and cleaned yet, from before my strict humidity control, but I have cleaned a lot of it over last several years. House is quite livable now, at least for me... Most of the old growth mold has been put in suspension by low humidity, but could bounce back quickly.

My property is on low ground so I often have standing water in my rain ditches. Days after every serious rainfall I still have water flowing in my ditches. After hurricane Katrina I used a small dozer and backhoe in my yard rearranging dirt to connect my back rain ditches, to my front rain ditch. They flow into two different outlets and the front system pulls down faster and lower. A gentle valley in my side yard routes back ditch overflow to the front exit pipe (reducing flooding in neighborhoods east of me.... they're welcome). Additionally I buried a 4" diameter drain pipe under my side yard, connecting back system to front, pulling down a few inches lower. Before these improvements my far back yard would resemble a lake, staying flooded for days after every rain. Now the water runs off relatively quickly.

I have a sump pump in my crawl space under my house to remove water after heavy rains (pulling air at the moment).

JR

PS: I am always working angles and considered pulling warm attic air for winter months, and cooler under house crawl space air for summer months. I was going to mount an in wall heat pump in my kitchen wall grabbing pre-heated/cooled air from my attached laundry room, with air moving fans alternately pulling/exhausting to attic or crawl space (both accessible from laundry room). I never did this and the laundry room would probably be even more hellishly unpleasant than it is now. Realistically I should probably just place a couple ton heat pump compressor on a slab behind my house.

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Re: UVc LEDs??

Post by JR. » Fri Mar 30, 2018 10:41 am

A perhaps interesting observation, that makes sense upon reflection. I notice when first powered on, the UVc CFL bulb glows yellow/orange for a fraction of second, until the UVc light starts up... Like any fluorescent lamp it needs to be started.

Of course I try not to stare directly at UVc lamps, duh....

JR

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