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-   -   UV or not to UV? (http://www.diychatroom.com/f17/uv-not-uv-77850/)

raff98 08-03-2010 06:04 PM

UV or not to UV?
 
Do they really work? I am going with 4" pleated air filter, I heard good things there. UV light, lots of contrasting views. Opinions?

Anybody have a UV light and think it helps?

Marty S. 08-03-2010 06:39 PM

They work very good. Put one in our house 6 years ago because my daughter painted all the windows shut. Not a big deal when it was hot but once it cooled off and the AC didn't run much we got mold growing on everything leather and the woodwork. No more mold after the UV light was installed. Every customer that has had one installed also really liked them.

Yoyizit 08-03-2010 07:45 PM

Quote:

Originally Posted by raff98 (Post 479973)
Do they really work?

Sounds like, "Yes". People are spending money to get patents on their UV sterilizing methods.

"
Ultra-violet radiation is well known to killing germs and viruses in the radiation range of 300-200 nanometers short wavelengths. Ultra-violet lamps have been used to eradicate germs, purifying air, water and surfaces. The intensity of the radiation and duration of exposure determines the potency of the ultra-violet radiation. The shorter the wavelength the stronger and quicker the kill factor. Ultra-violet light with wavelength shorter than 300 nanometer is extremely effective in killing microorganisms. The most effective sterilizing range of UV is within the C bandwidth [wavelength?] of 253.7 nm. This range is called germicidal UV bandwidth or UVC. "

Here's some prices for equipment possibly applicable to your situation
http://www.nextag.com/uv-light-air-purifier/shop-html

Questions to ask: what wavelength, what percent of microbes killed how quickly, what do replacement parts cost, how long do they typically last, any danger to eyes [very bright incand. puck lamps use UV filtering in their glass lenses]
?

Marty S. 08-03-2010 08:33 PM

Danger to eyes-yes. Must be installed in duct work and unplugged before opening to change bulb.
Bulbs need changed yearly. Cost depends what type of unit. The bulbs for mine are $35.
How long the balasts lasts I couldn't answer. Have many out there over 12 years old with no maintance other then changing bulbs.

Home Air Direct 08-03-2010 09:11 PM

Not only am I a customer of Hair for Men, I am also the owner of the company:)

Seriously, I have sold over 400 UV light systems in the past 3 years. In part because I have become a true believer. In the years 2005, 2006 & 2007, in late July of each year, I came down with serious bronchial issues. In 05 it was upper resp. stuff that took about 3 weeks to get through. In 06, it went insane again and this time instead of going to the bronchials, it went up into my meninges (skull area) and I was hospitalized for 2 days and the whole ordeal lasted 5 weeks. Then the mother of all infections hit the first week of July in 2007. This thing went nuclear and settled into my left lung as full blown pneumonia that included 3 days in the hospital and lasted over 7 weeks. i lost almost two months of my life.

After all of that I had my come to Jesus meeting and said: OK Idiot, you sell things that might help. Buy one for yourself! So, I put a UV Light and an Air Bear Filter into my Air Handler and "Knock on Wood", I have not been sick a day since:thumbup:

When choosing a UV product, be aware that there are multiple ways that UV treats conditions in air systems. Some light systems are intended to surface wash specific areas of your air handler and indoor coil. This the area that is most likely to have mold issues. Another approach is to sterilize the moving air. Both have their place in control.

Make sure that when you choose a light that you are getting a bulb that falls in the light spectrum at 254nm. This is the sweet spot for killing mold and bacteria.

Bulb life is specific. A 1 year bulb should be replaced after a full year or 9000 hours of service. The life of the ballasts is more dictated by the power inputs. Ballasts that only handle 24 volts are the most fragile and usually are warranted for 1-5 years depending on the manufacturer. Ballasts that 120/230 volt usually have 10 year to lifetime warranties.

I hope this helped.

jjrbus 08-04-2010 08:38 AM

I do not have a lot of spec's for you. But a close friend went to work for a company in NY that installs UV systems in commercial buildings. He made a believer out of me, it is almost a no brainier. If it does nothing else it will stop the growth of mold/ bacteria in the air handler which will save on cooling costs and cleaning the coils! Clean coils are happy coils:clap:
He does say that the placement of the light is critical, so do some research there.

http://www.vigilairsystems.com/

I'm not advertising for his company, he does not work there anymore. But a good source of info.
JIm

Earnie 08-04-2010 03:24 PM

Where is the correct location for a UV light?

For installation, do you just cut a circular hole in the plenum and attach the unit to the outside?

What is a good unit for a 3 ton Trane heat pump? Bulb wattage?

I see that some are 120 volt and others 208 volt. What is best for Residential use?

Does the bulb stay On all the time or does it cycle with the air handler?

This thread has educated me on something I had no knowledge of. Interesting that no HVAC contractor has ever mention it either, and I have went through many.

Home Air Direct 08-04-2010 05:25 PM

Quote:

Originally Posted by Earnie (Post 480396)
Where is the correct location for a UV light?

For installation, do you just cut a circular hole in the plenum and attach the unit to the outside?

What is a good unit for a 3 ton Trane heat pump? Bulb wattage?

I see that some are 120 volt and others 208 volt. What is best for Residential use?

Does the bulb stay On all the time or does it cycle with the air handler?

The best location is on both sides of an A Coil. One light can be used as well. on either side depending on what is in the line of sight.

You can mount the light through the air handler cabinet, but the best installation is internally with a magnet mount above the coil and through the end plate of the Coil.

120 volt is usually the best if you are planning on pulling from standard household current.

It is really best for these light so be on all the time. They are designed for this and the ones that are in the air handler are working even when the unit it not running. Turning these on and off is really not good for the lamps.

Hope this helps. If you would like, feel free to contact me and I will be happy to forward you an installation manual so that you can see the various configurations.

sktn77a 08-04-2010 09:57 PM

UV lights work well to keep mold from growing on the coil (when they are positioned at the coil). They are probably worthless in killing mold and other bacteria in air flowing over them in other areas of the ductwork at normal HVAC velocities. If the mold is static (such as on an AC coil or in a sterilization chamber), the UV light will kill it. If it is moving, there won't be sufficient exposure at typical duct air velocities (~600fpm).

yuri 08-04-2010 10:26 PM

Not necessarily true. The Lennox Pure Air system installs in the return air duct. Has 2 UV bulbs and can handle 2000 cfm on a 5 ton unit. Read all about it:http://www.lennox.com/products/indoo...y-systems/PCO/

Fairly expensive unit but people with asthma etc absolutely LOVE IT. Cuts down on the amount of inhalers/meds they have to use. Add on UV lights to keep a A coil mold free are a different story. The light has to bathe the coil properly.http://www.lennox.com/products/indoo...ty-systems/UV/

Home Air Direct 08-04-2010 10:30 PM

Quote:

Originally Posted by sktn77a (Post 480612)
UV lights work well to keep mold from growing on the coil (when they are positioned at the coil). They are probably worthless in killing mold and other bacteria in air flowing over them in other areas of the ductwork at normal HVAC velocities. If the mold is static (such as on an AC coil or in a sterilization chamber), the UV light will kill it. If it is moving, there won't be sufficient exposure at typical duct air velocities (~600fpm).

I agree that the highest kill rates are in the coil area. Stick lights are very specific in their use. Many of my customer have wanted to place the sticks in the duct system, but I advise against it for the exact reasons above.

If you notice the designs of the higher end duct mounted systems (Sanuvox for example), they have a turbulator box that slows the air passing through it down in order to increase contact time. The idea is not to kill on a first pass, but to get multiple opportunities to kill bacteria over time.

yuri 08-04-2010 10:36 PM

I am sure there are others besides Lennox that work well. You just have to do the proper research and get reviews from some scientific labs and not just trust brochures or salespeople. The catalyst in the Lennox is a honeycomb shape and that is probably designed to spin the air and increase contact time. All depends on the science and engineering they put into the unit. Most people use a ECM motor and continuos running fan at 400-700 cfm with these high end units and the multiple passing of the air does the trick.

Home Air Direct 08-04-2010 10:40 PM

Good point Yuri. The type of units that he is referring to, the combo, UV / Electronic / Media filters are great. They address in one unit, three different systems. Cost and maintenance is the trade off.

Now that I am a reformed reformer, it never ceases to amaze me that people will pay $8 for a ham sandwich at Panera, but they won't throw a few C notes in to get clean healthy air. Crazy world:huh:

yuri 08-04-2010 10:43 PM

Exactly. If it cuts down on the medications (which incidentally you get immune to) a filtration system is priceless. One of my customers has severe chemical sensitivity. Cannot go to work because of deodorant/after shave/perfume of co-workers. LOVES the PCO but it also costs $375 for a yearly maintenance kit. MERV16 5' filter, 2 UV bulbs and a catalyst.

Earnie 08-05-2010 08:15 AM

Other than Sanuvox, can anyone recommend other manufacturers?

Sure I can search but that doesn't tell me if what I find are good units. Would also tell me the quality of the unit my HVAC contractor might want to sell me.


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