Page 1 of 4 1234 LastLast
Results 1 to 13 of 67

Thread: UV Lights

Hybrid View

  1. #1
    Join Date
    Sep 2008
    Location
    Pittsburgh,PA
    Posts
    63

    UV Lights

    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

  2. #2
    Join Date
    Mar 2002
    Location
    Concord, CA
    Posts
    2,633
    -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.

  3. #3
    Join Date
    May 2005
    Location
    Lubbock Texas
    Posts
    769
    Quote Originally Posted by Irascible View Post
    -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.

  4. #4
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Quote Originally Posted by Irascible View Post
    -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.


    I've seen major mold growth at the inlet of a merv 14 filter,attached to the return inlet of an air handler,that's real close to the coil.

    UVC at the outlet side of the coil is a good idea for prevention.

  5. #5
    Join Date
    Aug 2011
    Location
    Eastern Shore, MD
    Posts
    798
    Quote Originally Posted by Irascible View Post
    -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.
    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.

  6. #6
    Join Date
    May 2005
    Location
    Lubbock Texas
    Posts
    769
    Quote Originally Posted by Gross View Post
    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.
    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.
    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.
    www.genesisair.com
    Genesis Air Inc.

  7. #7
    Join Date
    Jul 2011
    Posts
    8
    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.

  8. #8
    Join Date
    Aug 2011
    Location
    Eastern Shore, MD
    Posts
    798
    Quote Originally Posted by cnay20 View Post
    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.

  9. #9
    Join Date
    Aug 2011
    Location
    Eastern Shore, MD
    Posts
    798
    Quote Originally Posted by genesis View Post
    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.
    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.
    10000 mw at what distance? 10000mw at 1 meter would cook a bison

  10. #10
    Join Date
    Mar 2002
    Location
    Concord, CA
    Posts
    2,633
    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.

  11. #11
    Join Date
    May 2005
    Location
    Lubbock Texas
    Posts
    769
    Quote Originally Posted by Irascible View Post
    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

  12. #12
    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.

  13. #13
    Join Date
    May 2005
    Location
    Lubbock Texas
    Posts
    769
    Quote Originally Posted by breathe easy View Post
    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.

Page 1 of 4 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event