UV lights are they worth it?

Boss wants to install UVDI lights on all 7 McQuay roof top ac. I sat in the sales pitch and was not impressed. Sure the evap coil face would be clean where light reaches. But what about where the light does not hit?

I had never worked with uv lighting so I do not know how it performs.

The sale pitch was we are going to save energy using the uv lighting. They say we can use a better flow filter and uv lighting to keep the coil clean resulting in better heat transfer.:rolleyes: Saving lots of $$$$ while killing lots of germs.

I know hospitals had been using this for years but Iam sure that they would use something a little differnt than sticking some bulbs on the evap coil.

I've installed UV lights in water filtration systems before and I know they they are designed the water enters at one end ane exits the other of a long tube and the teeory is that the light reaches all the water to kill the crap. I see what you're saying about the places where the light would not reach but if it were placed properly in return air as i assume that's where it would go, you should kill the stuff before it gets to the coil

How well will it work and is it worth it? that's another story! lol

do you havea bacteria problem now? Or is this just a peventative measure?

-Mike

The rooftops are going on 7 years and I maintain them. The evap coils are very clean and we do not have an odor issue.
Boss likes the idea of saving energy and thats what their sale pitch is.:rolleyes:
I know it works but how well will it work for our facilty.

things i would consider haha besides the fact if it will do naything good

is it your money?
are you slow and wouldn't mind the work

if he wants them let him have his wish, if he's in the mindset that he need realy needs them who cares hahaha

The last I heard on this is the jury is still out. The airflow has too much velocity to be effective. The air must be in contact with the light for a length of time to kill anything. At the velocities we use, you'd better have many lights installed per unit to be effective. And there is the question of many lights restricting the airflow. The last I heard was if the maintenance of the airhandler is done properly, you shouldn't need uv lights.

Bingo!

The last I heard was if the maintenance of the airhandler is done properly, you shouldn't need uv lights.

You have to work here to understand. The penny pinching boss can spend money on this uv stuff for the claim on ROI but cries when we buy replacement parts or tools to do the job.

I work in a large research facility, we had a salesman come in with the same song and dance, so we had coil surface samples taken before and 2 months after uv lights had been installed. We were told that the lights have to be shining directly on the cw coils to be effective in controlling coil surface bacteria. (We have never had a problem with these units and bacteria). Not only was there not an improvement, but the samples 2 months after were slightly worse.The facility I work in does uv research and also took the samples, needless to say, we had them removed at no cost.

here in east coast florida, my swimming pool has a uv light on the filter system. when we get our heavy rains, my pool does not turn green or do i get any type of organism problem.

back about 8 years ago, a u.v. light co. gave me and all the company

service techs free u.v. lights. (they wanted us to sell them)

it worked for me in miami fl. it kept my TWE048P clean for years,

i could tell when one of the the lights would burn out, because i could see

scum start to build up thru the clear vinyl hose in the condensate

line, as soon as i changed the bulb the scum would stop forming.

i did change the filters regularly but the coil and cabinet stayed

super clean, that being said, it worked for me, i never would have even

considered buying one before i used this one.



.

i think that uv lights would work pretty well if you have living organisms. if you do not, it won't work. uv lights won't stop dirt. you might also want to talk to your equipment manufacturer. some plastics (like evap pans) and some of the insulation coatings on electrical wiring will not stand up to the lights.

We installed UV lights in our 16 AHU units during an upgrade of our controls and actuators. From my study and information from Central and South West Utilities and SMU I decided that we could install the UV lights and keep the coils continuously clean or let the buildup start anew and clean periodically. Since I have to contract all work on the HVAC system and since we will be implementing some form of Texas A&M' continuous recommissioning in the future, I felt that the best solution was to use the UV lights. We are still in the process of the upgrade, but the UV lights have been in operation for over six months and from what I can tell they are in fact keeping all the microrganisms off the coils. We were told that the lights will kill anything in its path within 10 seconds. Hope this sheds some more "light" on the subject for you.:)

It depends on how much UV you have and the velocity of the air. Usually, the air carries the organisms by too fast for the UV to properly treat them, but they are fairly effective in some cases keeping coils and drain pans clear of the little buggers. I have experimented with UV in my own home and right now have two photohydroionization lamps in my units and I have had some improvement in the air quality according to the Air Advice tests I have ran. I removed two UV lights some time back because there was no change in the results of the tests I was running. Yeah, the jury is still out on those things. I have customers who swear by them and customers who swear at them....lol.

Bobby

No. Got some new fan cabinets with them. Bulbs are very spendy and we also went through ballasts that were costly. They are no longer in use at this Hospital. Ken

Thanks for the input.
The boss needs to run it past the corporate office to get it approved so we will see.
If they do approve the install I will post the the results.