UV Lights for HVAC System

[seniorshoals]

I'll just add my two cents to this. I think that UV lights CAN and DO provide a benefit for HVAC systems by killing of the germs, mold, bacteria, virus, etc.

But from a practical standpoint, I've seen so many times where the UV bulbs are burned out, broken (as in broken glass!) or even unplugged/disconnected. A lot of times the maintenance guys don't bother with finding replacements, or their budget is limited and the last thing they will pay for is some UV bulbs when you got a motor go bad and leaky ductwork and all the other stuff you have to deal with every day.

So basically UV lights can be good but they need to be used. Plus from an engineer standpoint, I know you need to have slow airflow over the lights or they won't kill all the nasties that go by in the airstream.

[spyderwebb]

check out the RGF REME. To be honest, I've heard both sides that it didn't do anything, and that it helped. It's supposed to remove bacteria, virus', and mold. I saw the mold demo they placed a petri dish of mold in the supply by the register, and one in the return in a different room and let the system run normally for a week and came back to the petri dishes that had noticeably less mold in the dish. I'm always skeptical about demonstrations that i haven't done. so take it for what it's worth i suppose.

[Pogo007]

Hello,

I have the Honeywell Enviracare Elite UV Light that is designed for surface treatment (to prevent mold in a central A/C) and is placed in the supply duct in the air conditioning evaporator coil compartment. The model is the UV100E3007 SmartLamp single bulb 36 watt system. It was installed by a contractor.

The unit is less than 6 years old, and I just tried installing a new bulb (old one burnt out over 6 months ago), but the new bulb did not light. Actually, I bought TWO new bulbs, and tried them both out (one at a time), but neither of them worked. I installed them according to the owner's manual, making sure they were properly seated in the fixture, then pressed the Reset button for over 5 seconds, as recommended in the manual.

After the new bulbs were installed, the tiny LED light on the outside of the UV light fixture base began flashing (the manual states that the LED will blink when the bulb has 90% life left in the bulb), then the "light pipe" (the tiny clear plastic spot on the outside of the bulb handle which indicates when the bulb inside is illuminated) glowed very weakly (sort of an amber color) for two seconds, then disappeared, indicating the bulb was not illuminated. [When a UV bulb is working properly, the "light pipe" indicator will glow a brilliant blue color, and remain steady for the life of the bulb.]

I am trying to determine why the two new UV bulbs do not work. Could it be the ballast? I tried installing both bulbs several times with no success. I inspected the handle (knob) base socket (into which the bulb is installed) to see whether the 4 socket receptacles were pushed in or misaligned, but they were fine.

One would think that the odds of two new bulbs failing are tiny, but stranger things have happened, I suppose.

BTW, the unit and old bulb is clean, so dirt buildup is not an issue. (I have an EAC also.)

After reading these posts, I'm beginning to suspect it may be the ballast. If so, is that serviceable, or must I buy a new unit?

How was this resolved? I've got exactly the same problem!!!!

[Lennox Tech]

Ive been a firm supporter of Sanuvox UV lights for several years. I have yet to have a single customer naysay the product. The only initial complaint is that of an unusual odour, which is in fact the LACK of the normal odours found in the HO's living space.

All the hospitals and clinics in the area use them(may have to do with the fact that they are produced locally).

Bulbs need to be replaced and Sanuvox units in fact come with and indicator when replacement is necessary.

I only install merv 16 filters at the customers request and only if a biannual contract is signed. This is to avoid issues associated to blockages in the filter which the homeowner inevitably does not want to pay.

In the end it is based on personal experience as you can find "definitive" study's to support any position if you try hard enough.

[ws6guy]

I had mold growth on the ductboard surrounding my A/C coil. I have since replaced the ductboard around the coil and about 2 feet of the adjoining supply line. Now I'm thinking about adding a UVL by the coil but since I still have ductboard in the supply line I assume this might not be that great of an idea as the UVL might degrade the ductboard. There is about 2 feet of sheet metal above the coil and then the duct work makes a 90degree change of direction to the supply line and the duct board starts about 2 feet away from the 90 degree turn. It's a pretty safe assumption that the UVL will be reflected off the sheet metal and on the the ductboard. Any idea if this will be a problem?

[S B]

I've read lots about these things and have decided to try one out in the plenum by my coils. My question is with regards to the specific units. A ballast and a UV bulb seems simple enough - has anyone tried any of the less expensive dual bulb versions (from China I am sure) to compare with something like a honeywell for instance? I imagine they do the same thing but would like some real experience if anyone has used one of the less expensive versions.
thanks!

[spyderwebb]

@ ws6guy

From what I understand about UV bulbs, It's only affecting the bacteria it comes in contact with. Surface area taken into account, it doesn't seem like much. From what i've learned about the REME and Guardian Air, they both create hydro peroxides - as opposed to just affecting the air running across it - essentially sending these particles through the duct work and the house effectively.

[mark1369]

I wasn't a believer until I purchased an Air Knight. I actually can tell a huge difference in my home and I do highly recommend that product to my clients.

[airtrackinc]

HVAC UV lights:

Control mold and bacteria
Reduce colds and flus – germs are not re-circulated by HVAC system
Reduce smells / odors
Remove VOCs
Are more effective in humid climates than dry climates
Reduces clogging in condensate drain lines by preventing algae growth.
Maintain a cleaner coil, improving cooling efficiency and reducing electricity costs.

[Hut1]

Uv lights are effective at the unit but I always recommend taking it a step further and investing in an air purifier.The Air Knight is a good product with two different models to chose from.Ive been in this industry for 20 years now and the most effective product I've found and use in my own home is the Air Scrubber Plus.


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[aquadave]

I swear by them! but most use the wrong size light and are a waste of time and money. always go up in size 18w per 1000ft. They do not remove anything (dust dirt etc) just kill bacteria, mold and viruses. They also help remove odors both VOS and organic. They should be required on all public buildings. For air systems Ozone works better but it's harder to control. For people with allergies UV is a must

[Adir Aflalo]

From my experience installing the UV light closer to the evaporator coil is the most effective way. From the simple reason that most of the condensation occurs there.
Water,heat,humidity= bacteria,mildew,mold,att
Obviously with good equipment and not the cheap once.
Prevent future costs of cleaning and sanitations.
Very recommended to install when you purchase a new hvac system period.
Specially if one of the family members has breathing issues.

[jkbama]

At one time I was skeptical about the claims regarding UVC lights and health issues. As I understood the effects of UVC in HVAC systems the UV radiation would outright kill some biologicals or sufficiently damage the 'DNA' as to preclude reproduction.

My first introduction to UVC lights was in 1996. I was asked by my supervisor if I could recommend a test site in one of our schools that was experiencing complaints of 'bad IAQ'.

I immediately recalled a principal who mentioned headaches, scratchy throat, itchy eyes, etc; you know the script. It only happened when she returned to the school; no problems at home. She didn't make a stink about it; just put up with it.

In August, when the office was vacant and no one was around to snoop, I installed 2 UVC fixtures with the bulbs approximately 4 inches from the downstream side of the center of the evaporator coil (this is a dual circuit 15 ton package rooftop heat pump and the evaporator coil is over 4 feet long and about 2 ½ tall, so it took 2 fixtures to cover the length of the coil). I wired the lights to remain on all the time.

No one observed me working on the unit and I never revealed the existence of the lights.

Around the middle of October, I offhandedly inquired of the principal about her headaches, etc.

She said, “You know, I hadn't thought about it until you mentioned it, but I haven't had any problems since we came back.”

I still never told anyone about the lights.

This impressed me enough to install them in my home. I saw the advertisements showing how it cleaned the upstream side of the coil of biological film and kept the coil shiny by reflecting back and forth through the fins; I thought “yeah, right” but I wasn't really concerned with that as much as I was the IAQ benefits.

I lined the inside of my air handler with heavy duty aluminum foil to keep the UV bouncing around (could also irradiate the blower wheel) and installed the light approximately 2 inches from the downstream side of the coil.

After 2 weeks, I examined the upstream side of the coil and was surprised to find that it was indeed as shiny and clean as the ad photos claimed.

Truth in advertising. Go figure.

I've only installed one other light in a storage portable that had suffered a mold outbreak all over the walls, floors, ceiling tiles, shelves, files, supplies, etc. After remediation, the light was installed and has been in operation for about 6 years with annual replacement of the bulb (files and records are important enough to warrant this).

I've seen that 2 year bulbs are available now.

Empirical evidence at best, but I'm a believer.

where was UV put?