Bubba wrote:
On Wed, 13 May 2009 11:24:08 -0500, The Daring Dufas
wrote:

Bubba wrote:
On Sun, 10 May 2009 07:25:51 -0500, The Daring Dufas
wrote:

RBM wrote:
"The Daring Dufas" wrote in message
...
John Grabowski wrote:
"RBM" wrote in message
...
"John Grabowski" wrote in message
...
"RBM" wrote in message
...
A customer of mine inquired about a UV filter to install in or on a
central AC air handler to kill mold growing inside the cabinet and
duct. Is anyone familiar with these, that can give me any detail on
how and when they are used and work.
*Roy it sounds as though you want ultraviolet lights for inside the
ductwork. I've seen these used in hospitals, but I don't have any
details. I have also seen the ones used on water filtration units
connected to wells. The idea is that the UV light kills bacteria. Try
talking to an HVAC company.
Thanks John, I don't know who initiated this, possibly the HVAC service
company, and the homeowner is trying to get other opinions. From the
homeowner description, it's just going to be some type of UV light
installed in or on the air handlers. The claim is that there is mold
growing inside, and the UV will kill it. I've worked with the ones on
spas, and water systems, but I've never seen anything like this. It
didn't sound like they were going to be installed throughout the duct,
as you describe, which makes sense to me, just something in the blower.
He didn't give me a number, but said it was wicked expensive. A Google
search didn't turn up anything that was convincing to me. I suppose I
should have him get more specifics from the contractor, so I have
something more tangible to look into.
*Roy I'm thinking if there is existing mold in the ducts that a
remediation company should come in and clean first. The Ultraviolet
lights are only placed near the air handler to my knowledge, not
throughout the duct work so they would not do much for anything beyond. I
would think that the source of the mold should also be addressed rather
have something to keep the mold under control. Perhaps moisture is
getting into the ducts and condensing or they are up against a moist
surface such as a basement wall.
The UV light around the evaporator coil kills the
the micro-critters that can grow on the wet coil.
That area of any HVAC system is where microbes can
grow because that's where a lot of water and debris
can collect. Some evaporator coils are coated at the
factory with an antimicrobial compound that will help
kill off the little beasties. Anything that can kill
mold and mildew around the evaporator will also keep
the odor level down. I've seen yeast grow in the darn
things, some folks like to bake their own bread.

TDD

Is there not some type of spray on coil cleaner antimicrobial stuff that can
be applied when the units are serviced? Do you recommend any type of UV
beast killer?


The supply houses have all sorts of UV units
on display and there has been a big IAQ "Indoor
Air Quality" push going on for a while as another
revenue stream for HVAC companies. I don't look
at the UV lights as a gimmick or snake oil but
like anything, if properly designed and installed,
the UV lights should function as advertised. If
the equipment is not installed as per manufacturers
instructions, I would doubt the effectiveness. A
lot of gear is sold and just thrown in without a
lot of thought and when it doesn't work right, a
lot of folks will be prone to bad mouth the product.
I haven't installed any UV lights in any HVAC units
yet and I haven't tried to sell anyone on them. I
do use a lot of cleaners on both evaporators and
condensers to keep refrigeration and HVAC systems
running. Dirt is the big enemy of such systems.
A friend and me recently cleaned and treated a large
evaporator for a drug store where they had an odor
problem. Here's an example of some of the products
we used for that job:

http://tinyurl.com/pr3ntl

http://tinyurl.com/r69dav

http://tinyurl.com/r5snwd

TDD


Here are a couple I use. Different prices and applications. These are
indoor air quality products. They work just. They dont perform magic.
They wont cure a mold problem or asthma. It is merely another product
to help the indoor air in homes. Proper application is key. Some go in
the return duct, some in the supply and others are helpful in the
inlet of the cooling coil area.
Choose your poison. :-)
Bubba

http://sanuvox.com/sanuvox_residential_products.htm

http://yourhome.honeywell.com/Consum...Air+Treatment/

http://www.fieldcontrols.com/uvaire.php
Hey Bubba, in your experience, what kind of lamp life
are you seeing with these UV units? One of the first
questions I'll get is "how long will it last?"

TDD

1 yr and 3 yrs depending on the brand. The Honeywell is 1 yr. They
tried to make a "smart lamp technology" and a light that tells you
when to replace but when you have a customer with a variable speed
high end unit and electronic cleaners and UV's they tend to run the
blower 24/7/365. So it lasts a year and gets replaced.
The Sanuvox is 3 yr. It will last beyond that but its effectiveness
diminishes.
Basically you just have to do the math and figure the cost over the
life and recommend the best to your customer.
Bubba

Me and my friend who I do a lot of HVAC work with have
never installed any UV lights for anyone. Most of our
customers are price shopping and I don't know if I could
sell them on it. I wonder if there is a light designed
for a package unit?

TDD