St Louis, Missouri
Originally Posted by alohaair
Please Help Me
I have a "UV aire UV-18" on one side of my heat pump Coil "A" frame coil. It comes on when the fan comes on and turns off when the fan turns off (it wired into the fan). Right now I need a new bulb is it worth replacing?
It is mounted above the "A" frame so only one side of the Coil "A" frame see light. Should I have one on the other side or should it have been mounted on the bottom of the A frame (down stream)?
Anything producing more than 55microwatts/1meter CAN kill/sterilize organisms while moving in the airstream. Westinghouse confirmed that....its just that most UV lights are crap. A UV lamp producing UVV rays can produce ozone...a LOW amount of ozone usually less than 10 PPB when measured at the registers...they arent high output ozone generators.
Originally Posted by Irascible
Let me rephrase that old post by saying that it's about a fifth of a second of exposure, depending. You're not going to sterilize much of anything in a fifth of a second.
What they have is testing that isn't applicable to a real world application with their test data. 1500 cfm with the data they have on line is about 250 fpm. Thats half of the design airspeed across an evap coil.
Originally Posted by Gross
And another misnomer is UV lights produce ozone. By design they can, but when using the proper glass and keeping the wave length above 254 nm there is zero production of ozone. According to the gurus at Penn State in indoor air quality. Using their numbers in a 500 fpm airstream it takes ruffly 72 seconds with 10,000 uv micro watts to totally destroy 1 spore of aspergillus. How the light companies fudge the numbers is that they are counting on multiple passes thru the lights.
As an irradiation device on the coil they are a perfect fit for biologic reduction on a coil, or for upper air UV in TB and Legionaires control. As for an IAQ reduction device do the math. There is simply not enough residences time in an HVAC airstream. I believe I have already posted those numbers in this or another post.
An lastly not all uv lamps are manufactured the same. We dropped a top manufacture of lamps for lack of consistancy in the lamps we purchase to iluminate our catalyst systems many years back. We have purchased more than 12,000 lamps this year alone for our PCO systems up to 5 foot in length. Our shop tests the UVC output of every shipment we recieve. Since we use it as an energy source to activate our Catalyst Racks.
The premise of ventilation is that the OA is clean or of sufficient quality to be used for dilution. Traditional ventilation is somewhat being threatened by the fact that the EPA is changing the requirements for outdoor air quality which is creating non-attainment zones in what is now becoming a significant portion of the country. That means that buildings in those areas will need to clean up the OA before they bring it into the building.
Genesis Air Inc.
The uvc light should be placed on the downstream side of the cooling coil. Putting it in the duct makes it try to function in "blow by" mode and is at best 70% effective. Also there are alot of different uvc lights out there some of which do not cause ozone. Also a bulb will only last between 9 and 12 months before it loses it effectiveness.
That completely depends on what youre trying to do with the lamp. UVC bulbs wont produce ozone, UVV lamps will. if youre simply trying to kill VOCs and airborne bacteria, germs and viruses (assuming you have a lamp powerful enough) it doesnt matter too much where you put a uvc only bulb. as for them only lasting 9-12 months....thats low quality lamps...get something that has a higher micro wattage rating...ours are 180 at 1 foot. You lose about 30-40 % of that every year due to solarization of the bulb...since most lamps aren't worth a crap anyway(hence they start at 60mw) and they need to be above 55mw to do anything in a moving airstream...they are ineffective rather quickly in killing stuff in the air stream... When youre trying to do that, look for a longer piece of duct(return drops are good) because they will give any baddies a longer dwell time and thus a higher killing rate.
Originally Posted by cnay20
10000 mw at what distance? 10000mw at 1 meter would cook a bison
Originally Posted by genesis
I was not a fan of UV lights until I installed this new APCO into my own house. I sure won't sell them to anyone unless I feel they do what they are suppose to do. I had a slight dog smell in my home due to having 4 dogs and now with this light its great. I sell lots of them now and all my customers are happy as can be and can actually smell the difference. Triatomic Environmental is the builder of this local product but most all supply houses carry them or call out a local contractor and have them install an APCO for you. Best thing is its made in America. Right down here in south Florida
We are thinking about installing a Respicaire UV light for a customer with mold issues @ the evap coil. Does anyone have experience with this particular brand? Opinions are welcome!
Almost any uv light will take care of the evap alone... Won't do much for the airstream with out decent power
Originally Posted by arae0122
hi guys, we work extensively with second wind and after reading this thread and another one I forwarded him the link and this is the response I got from tom wilson the president of second wind. I personally love their products and have one in my home. I notice a difference and will probably never have a home without one again. I have it installed in the cold are return down leg and have an aprilaire media filter intalled and have never noticed any holes or deterioration.
“stick lights” as they were called in the first thread are those that are low powered systems like our 24V series which serve the purpose of cleaning the surfaces of A/C coils. Their UV output is low and power draw is low also as the coil is bathed 24/7 in UV light, which even at low levels is sufficient for surface disinfection. The Carrier device mentioned in the thread is industry defined as a “stick light”. These work great when properly used and help with efficiency and preventing surface mold and mildew from growing on the coil.
A unit like the Second Wind 1000KCS operates at a higher UV output than those systems as it runs a higher powered ballast creating a higher intensity of light to create a field in the ductwork. Our 2000 models is even higher. These intensities provide contaminants with more than just a “tan” as one of the writers put it. The dosage of UV light begins when the pathogen is first exposed to the UV, and until it leaves. UV lamp intensity is rated at a distance of 36” (that’s a 72” total range) that nasties are being bombarded by germicidal light.
There are many variables to make calculating the UV dose of a contaminant difficult. For this calculation, we expect the return duct to be at a velocity of 3ft per second. Using only the UV rating distance of 36”, the contaminant would be dosed for 2 seconds.
A kill time for a contaminant is shown here as an example:
Infectious Hepatitis requires 5800 microwatts seconds/cm squared to achieve a 90% kill rate
Second Wind 1000KCS lamps each produce 374 microwatts/sq cm at 12” distance. As virus gets closer, intensity increases then decreases as the target moves away from the lamp.
Total number of seconds for 90% kill = 5800/(374*2) = 7.75 seconds
In a home, if air circulates at approx 4 changes per hour, the virus would be 90% killed in less than 1 hour
Second example (2000 series, High Output lamps) with same pathogen:
2000 series lamps produce 1440 microwatts/sq cm
Total number of seconds for 90% kill = 5800/(1440*2) = 2 seconds
In same flow rate, the virus would be 90% killed in first pass of airflow –HARDLY A TAN, it would be DEAD
The 1000KCS system produces the singlet oxygen that you can smell, knowing it is operating as you note in your testimonial. The singlet oxygen has a life of a couple of seconds where it is attempting to attach itself to carbon based contaminants to further assist their breakdown after it leaves the direct UV contact. Homes with young children or elderly residents or acute breathing problems should not use the 1000KCS. Many of our competitors make similar products to this 20 year technology of Second Wind.
The 2000 system is one that we sell most often, as it does not produce singlet oxygen but a side effect of that is that you cannot smell its operation as you note in your testimonial. The odor control from this process is created by the titanium catalyst placed near the lamps. When the UV light hits the catalyst in the presence of airflow and humidity we create hydroxyl radicals which are more aggressive than singlet oxygen or ozone, but have an even shorter lifespan. This process attacks off-gasses and odors much quicker and breaks them down. This product is safer for all residents young and old.
Attached is 3rd party test data from a university in Ontario, Canada that shows how quickly our model 2000 broke down intense presence of different model contaminants (E.coli and toluene). The summary at the beginning of the document expresses that this unit will break down microbes and dramatically reduce VOC’s (off-gases and odors). These tests were conducted in sealed environments that were completely contaminated with the model (imagine putting a Second Wind device in an enclosed box and sealed air system that passed by the UV lamps). The time for complete eradication of the nasty is shown. Our current experiments with this same university will be introducing household levels of contamination showing their breakdown.
In reply to the preceding post:
Sterilizing the coil might be needed in humid climates. It’s certainly not needed here (a dry climate) in a typical residential application. Regardless of the climate, AFAIK there is no data that shows the true rate of coil contamination or the rate of clinical problems that result from said contamination.
Assuming a three foot per second velocity for the return highly unrealistic. Three times that is more typical and very likely renders the machine ineffectual.
Hepatitis as the example bug? It might have been better to pick a bug that’s actually airborne. I suspect fluid, food and fecal bound bugs like the various strains of hepatitis are more easily killed by UV than a bug whose design allows it to survive the bright and dry conditions inherent to being airborne.
Ignoring the other two bad assumptions for the moment, you’ll never get a 90% kill rate because you won’t circulate all the air four times. Mixing just isn’t that good in most homes and is often terrible.
Producing highly reactive oxygen, that lasts for up to an hour according to Wiki, sounds like a good way to damage my cells. Get enough of it and the big C may eventually follow. Anything with a warning for the elderly and young should give pause to the rest of us. Just because I can survive a night of heavy drinking that would kill an old timer doesn’t mean it’s good for me in the long run. Just because a heavy concentration of free radicals doesn’t irritate me today doesn’t mean that’s good for me in the long run either.
In short, (barring new information) coil bound bugs (if they exist in a way that matters) might be killed till the thing wears out. The airborne bugs get a tan. And I (might) get cancer (if I actually spent the money maintaining the thing, which no homeowner I’ve met does).
Last edited by Irascible; 09-03-2012 at 06:12 PM.
Reason: added clarity