UV Lights

[bowhunter21]

I am thinking of putting a UV light on my furnace, I am just wondering if anyone knows if they actually work and if it is worth my time and money to put it in? Any info would be greatly appreciated.
Thanks in advance

[Irascible]

-A UV light can sterilize a nearby stationary surface. Most residential systems don't need that because they dry out during the off cycle. The baddies can't grow without sustained moisture.
-A UV light can't sterilize the moving air stream in an HVAC system. The baddies get less than a second of exposure as they whiz by the light.
-A UV light can and will require yearly replacement to maintain its output of UV light. The pretty blue hue is obviously not UV. The hue will stay. The UV will not. Your contractor thanks you in advance for the revenue stream.
-A UV light can also break down any plastic and other petroleum based components nearby. Luckily few people ever deal with that because they don't bother changing the lamps on a yearly basis.
-Some UV lights can also put off fancy sounding free radicals that supposedly seek and destroy baddies. They also seek and destroy lung tissue. Think ozone machines - once promoted by some as healthful, now regarded for the pollution makers that they are.

[genesis]

-A UV light can sterilize a nearby stationary surface. Most residential systems don't need that because they dry out during the off cycle. The baddies can't grow without sustained moisture.
-A UV light can't sterilize the moving air stream in an HVAC system. The baddies get less than a second of exposure as they whiz by the light.
-A UV light can and will require yearly replacement to maintain its output of UV light. The pretty blue hue is obviously not UV. The hue will stay. The UV will not. Your contractor thanks you in advance for the revenue stream.
-A UV light can also break down any plastic and other petroleum based components nearby. Luckily few people ever deal with that because they don't bother changing the lamps on a yearly basis.
-Some UV lights can also put off fancy sounding free radicals that supposedly seek and destroy baddies. They also seek and destroy lung tissue. Think ozone machines - once promoted by some as healthful, now regarded for the pollution makers that they are.

Irascible your my hero
Your dead on about 99.9% UVGI lighting will deduce and deactivate a small percentage of biologics in the air by them selfs. But it takes so many multiple pass they are not all way feasible unless laid out correctly in an air stream. And most residential situations they wont spend the funds to do it correctly or there is no real space in the duct system that is safe to put that many lamps with out destroying all of the flex connections and duct board plenums.
Wait till March our product line is being release by Trane. All I need is 6 inches of duct space at the coil box.

[Irascible]

Hmm...

That will be interesting to see. You and breathe easy are about the only two on this forum that I've seen engage in real scientific discussion on IAQ. (That's not to say there aren't others.) I can't wait to look skeptically at your/Trane's new product. I look skeptically at all new IAQ products because I'm sure you'll agree that the residential IAQ market is dominated by snake oil.

[genesis]

Hmm...

That will be interesting to see. You and breathe easy are about the only two on this forum that I've seen engage in real scientific discussion on IAQ. (That's not to say there aren't others.) I can't wait to look skeptically at your/Trane's new product. I look skeptically at all new IAQ products because I'm sure you'll agree that the residential IAQ market is dominated by snake oil.

Well I hope you take a good look at it and any questions,data,testing is available to the contractors and end users. This is a product line developed by HVAC technicians and contractors and engineers then brought to market by them. I hope we are a little more in tune to what is really happening in the world.
http://www.genesisair.com/PCPStandardInstallJpg.htm

[breathe easy]

Thanks, Irascible.

Your UV light answer pretty much sums it up for me on the typical residential UV light installation. One bulb in the airstream is good for giving mold spores a nice suntan as they pass by.

However, I have seen some encouraging data on commercial UV systems with longer, multiple bulbs (4 to 6 in a duct). So, done correctly, UV lights can work. I think the same holds true for PCO. Done right, it can work effectively. Genesis just about has me convinced that they are doing it right.

[genesis]

Thanks, Irascible.

Your UV light answer pretty much sums it up for me on the typical residential UV light installation. One bulb in the airstream is good for giving mold spores a nice suntan as they pass by.

However, I have seen some encouraging data on commercial UV systems with longer, multiple bulbs (4 to 6 in a duct). So, done correctly, UV lights can work. I think the same holds true for PCO. Done right, it can work effectively. Genesis just about has me convinced that they are doing it right.

Dealing with that one right now. We are reproducing the UCB test on PCO at RTI. With a few exceptions like proper PCO. No ozone producing lamps. And a lab a little better than the double-wide mobile home they used.

[dougvhvac]

I am thinking of putting a UV light on my furnace, I am just wondering if anyone knows if they actually work and if it is worth my time and money to put it in? Any info would be greatly appreciated.
Thanks in advance

Bowhunter - you did not say why you were considering a UV install. Although my esteemed colleagues have reservations regarding UV efficacy I'm sold on the value. Previously I was very skeptical. In my home I have 2 units and they have made a difference, but it is in combination with great filtration also.

What sold me was an experience with a customer (not my install) that had UV retrofit and it greatly improved his son's severe asthma. When the bulb burned out, his son got worse - prompting a service call that we responded to. Checking out the other company's install base (we acquired them) many folks had similar stories. My wife is an RN - in the hospital UV is used in many ways to sterilize instruments. The pool industry (and tropical fish guys) use passing exposure to kill nasties with success.

Just wanted to offer a different perspective; if there's a 'need' it may be a useful addition to your system. I'll never have a home without it.

[colt45]

We use single Carrier branded uv lights on the return side on the evaporator and it does really well with mold growth on coil, South GA has a lot of humidity and the lights really work.

[ptbrunet]

My 1.5 year old HVAC system started exhibiting a very bad DSS (Dirty Socks Syndrome) smell when I turned it on during the Christmas break. I would like to buy the most economical and cost effective UVC light, considering the long term 10 year cost of the initial purchase and replacement bulbs.

I have 2 Amana (Goodman) HVAC units, one each for each floor (1000 sq ft per floor). Each unit is dual stage (2 tons, 3 tons). The CFM for one unit is 715 and 644 for the other.

I want to install the light between the two slabs of the acoil. (That's downstream in my case but there isn't any room upstream; the furnace butts right up to the acoil enclosure.)

I am considering the American Ultraviolet Eliminator RPT which has a high output 12K hour bulb. Of the various products available, do you have a better recommendation?

[Keith Jordan]

I am in agreement to the stick lamps out there are only good for cleaning a coil or surface. That's the easy part to UV which has so many companies jumping into the market - surface disinfection is a breeze with UVC. Thus that's what leads to all that marketing hype out there. Getting very annoying the mis-information.

Air purification is a different animal and there are many more parameters to deal with to perform a proper kill rate with moving air.

Genesis, I have a question for you. We have spoken with American and Overseas manufacturers of PCO and both state that with UVC light shining on the PCO, the PCO reacts fine, but the paint or whatever is adhering the TiO2 to the surface flakes off to where within months you have to re-apply the PCO. The manufacturers say UVA works better and for a longer period of time, but you lose the germicidal effectiveness if you use UVA.

How is it working for you? Aren't you using UVC?

[genesis]

That's where one of our patents is at.
This message will self destruct in 12 hours

[Keith Jordan]

Very good. We may have to talk. Can you email me your contact information?