UV Light to Kill Germs

[floridafarmer]

I'm starting to see a few more ads on UV Lamps integrated into my central AC unit to help slow/stop bacteria and germs...
With all the paranoia lately it's interesting to me that this is not getting more attention if it's real -
I'm curious if any pros on this board have a opinion - with a new granddaughter I'd spend the $$ just to help if there is really any merit to it.
Thanks in advance for your thoughts.

 

[ddawg16]

For the furnace? Gimmick in my opinion. If the germs get into the HVAC, you have bigger issues.

But it's not a bad way to clean surfaces in the house of live germs

 

[Ilikeike]

UV is common in water treatment to kill pathogens, not sure if the contact time in the an HVAC system would be sufficient ?

 

[harley jim]

I worked for an HVAC company for a couple of years, I thought I wanted a change in my life anyway.
The owner of the company sent me to school to learn about some new directions he wanted the company to go in. Part of the school was on uv lights, they do work they do kill many viruses and a condition at the condenser that causes a distinct smell in the air(some refer to it as stinky sock syndrome) it will also help in new construction where the new house smell is strong I installed one at my last house as it was new and it would irritate your eyes.

Sent from my SM-A102U using Tapatalk

 

[brewchief]

They do work but are only going to kill germs that pass in front of them, useful to keep mold from growing on an A/C coil but won't do much for for a virus like the covid-19. They do certainly have some merits but they are not a miracle device. To be effective the fan needs to run all the time and that can be costly on equipment without a variable speed motor.

Sent from my SM-G965U using Tapatalk

 

[marinusdees]

I worked in another life in a winery (in Michigan). They were using UV lights in an attempt to keep grape juice from fermenting (they sold grape juice and grapes sold for grape juice and grapes sold for wine had to be kept separate for legal reasons). In my experience, the UV lamps were effective up to a distance of two inches (max).

 

[PelicanPines]

We had UV uplights along each wall in our towns board of health. I recognized them from an animal clean lab I did microscopic necropsies at... fun times...

Heard they work by some... gimmick by others. The lights were aimed at the HVAC outputs into the room. Being clean... the air was already heavily filtered. Come to think of it... maybe it was on the return air ducts... don't know now.

 

[danski0224]

I'm starting to see a few more ads on UV Lamps integrated into my central AC unit to help slow/stop bacteria and germs...
With all the paranoia lately it's interesting to me that this is not getting more attention if it's real -
I'm curious if any pros on this board have a opinion - with a new granddaughter I'd spend the $$ just to help if there is really any merit to it.
Thanks in advance for your thoughts.

Try to find some actual scientific type specs on any residential market HVAC UV lamp accessory...

Yes, the UV will kill growth on an evaporator coil, however, if one is having issues with biological growth on an evaporator coil, then there are certainly other major issues in the home/building.

UV-C does kill bacteria and viruses.

The sell sheets/specs list bulb age (typically 100 hours), specify that the bulb surface is clean, airspeed (feet per minute) and a kill radius from the bulb. Performance may be reduced if the bulb(s) are installed downstream of an evaporator with the AC on, due to the cooling.

If your HVAC system operates within the specs required for the UV bulb, then you will be good to go.

Proceed with caution after educating yourself.

 

[jjrbus]

A friend worked for a company that installed UV lights in large commercial setups, hospitals and such. Their purpose was to keep the coils clean and reduce maintenance.

Been looking into it as the blower wheels on my minis are mold magnets.

Any claiming to be a whole house solution by putting small unit in the air flow is full of ****. I am You Tube and Face Book certified, so know what I am talking about LOL

 

[floridafarmer]

Thanks for the input - sounds like maybe good for keeping the unit cleaner but not much help beyond that....

 

[MBfreak]

I have seen and worked with two applications, both very pro setups.

A surgery in a hospital where we did electrical installation had a large amount of UV fixtures in the entire area. Store areas, waiting rooms, offices , wet rooms and the operating theatre had UV fixtures that were switched on as soon as an area was not used.

On a large sea based substation collecting and transmitting sea based wind power to shore there were also living quarters for service personnel. Salt water was desalinated and processed, the last stage was a large glass cylinder 400*2000 mm with integrated UV lamps. This was for the potable water only.

So yes , it definitely works.

If it is applicable in air handling units of a HVAC plant ( legionaires disease?) I have absolutely no idea

Ola.

 

[dogdog]

UV-C light (185nm is ozone generating, 245nm is non-ozone generating) works in some sense, that it kills the germs and virus on the surface where the light hits for X number of seconds or minutes, it is not instant germ killing. Not too sure what the power requirement for it when Air flows through it.

I would just be beware of gimmicky sales... and over execrated claims, especially the ones that have corona virus + some one smiling with their teeth so white + the guy's shirt is way to clean to work in the field + he squats like a monkey. Everything of a marketing scam.

 

[Aileron]

36 years in the commercial/ industrial industry and have had a set in my home for the last 15 years or so. I did noticed the kids did not get as sick as often. Yes they work, but are a maintenance item. The uv bulbs have a life span and should be replaced every year. You can go two years but the bulb loses its effectiveness. Depending on the brand you purchase the replacement bulbs are expensive. The name brand price on mine are around 65-100.00 a bulb and uses 2. I buy them off amazon, not the name brand around 35-40 ea.
You have to be careful that no light comes outside the duct. You can get flash burned easy. Before I had a steam humidifier I used a AprilAir with the water pad. Their water pad would get mold spots on it, the lights fixed that. One other thing to consider, if you have plastic that gets hit buy the light, it will degrade it. Kind of weird this came up as I was getting ready to install a set in my daughters home today.

 

[Aileron]

Mine are twin 17" long bulbs mounted right above the Acoil.

 

[malibu101]

I remember in high school shop class (about 35 years ago) there was a cabinet that stored the safety glasses that were shared among each class.
This cabinet had some sort of blueish light that was turned on once the cabinet doors were closed to "sterilize" them for the next use.

I've thought of this over the years but didn't know it was such an "advanced" technology that's still in use with todays high tech stuff.
I love the diverse things that can be thought about and learned here at GJ!

 

[dogdog]

I remember in high school shop class (about 35 years ago) there was a cabinet that stored the safety glasses that were shared among each class.
This cabinet had some sort of blueish light that was turned on once the cabinet doors were closed to "sterilize" them for the next use.

I've thought of this over the years but didn't know it was such an "advanced" technology that's still in use with todays high tech stuff.
I love the diverse things that can be thought about and learned here at GJ!

We have one in every shop class in the HS as well... you'll see a timer that says 15 minutes... the time it takes to be effectively sterilize all the say germs / virus it's suppose to kill.. some where in the warnings. So it works, sort of, air in a HVAC duct would not stay 15 minutes to get sterilized. That is probably why it is installed so the lights hit the condenser coils and the heating chambers.. It is only effective in killing the Say Germs or Virus that would have been collected there and some how survived. It would probably not be effective on air passing through the chambers if anything.

I have 4x 25watt CFL bulb type 185nm O3 type that I used on a clip on E27 bulb holder and use it from room to room but that surface and air are treated 15 minutes to 30 minutes at a time... a bit different from expecting the UVC will kill the virus in the air while passing through it.

 

[ddawg16]

Consider this....for the air to reach the HVAC system, it has to pass through the house. If there is anything in the air to hurt you, chances are it has already landed on a counter top or you clothes.

Basically, you're treating it after the fact......

If the germs get into your house, chances are it was from a person....and it's too late.

Just change the HVAC filers on a regular basis....

 

[Dumber than lumber]

Consider this....for the air to reach the HVAC system, it has to pass through the house. If there is anything in the air to hurt you, chances are it has already landed on a counter top or you clothes.

Basically, you're treating it after the fact......

If the germs get into your house, chances are it was from a person....and it's too late.

Just change the HVAC filers on a regular basis....

That is an incomplete way of looking at it. **** can grow in the ductwork and in the air handler. That stuff is going to be on the other side of your air filter. And a lot of the junk that gets on the counters (for example) will die once exposed to fresh air or sunlight. Inside the ducts and air handler it is dark, and can also be damp. The right UV lights are beneficial.

 

[SGKent]

If sunlight (UVA and UVB) destroyed* the virus it might work but last I checked the studies show that it takes a very long time for UVA and UVB to destroy SARS COV-2 (Covid 19 - Corona virus). If the level of UVC is increased to the point of blinding you in seconds, that does kill it but then you will need a cane to get around after you get over the intense pain you will have from your eyes being burned.

*Viruses are not considered living. They are escaped packets of DNA and RNA capable of replicating themselves by taking over living cells.

 

[TangoFoxTrot]

It just would seem to me to do little to nothing on keeping occupants "healthier" in terms of flus and colds.

The viruses and "germs" that make you sick would have to be brought in by a person from the outside world. So you have already been exposed. You're then hoping all of that gets sucked into your vents and becomes sterilized.

Now if you have weird mold growing in your ducts and on your coils, I guess I can see the use of it. That's a different set of issues though.

 

[dcg9381]

I use these for my water system(s). Just be aware that they have a useful life - in the case of water sanitation of about a year. And I've found that the ballasts generally have a life of 2-3 years, give or take...
Flow rate of water is easier for me to calculate, so you could figure out minimum exposure - I can't imagine how fast air can move through an HVAC system - IE, you're gonna need a BIG bulb..

 

[jjrbus]

Any thoughts on the LED UV lights that are becoming available?