Hydroxyl Radicals

[cashcow]

I've been researching the Lennox Pure Air system. Accorded to Lennox product data the system produces "Hydroxyl Radicals" to purify the air.

Google "Hydroxyl Radicals" and you get opinions all over the board whether they are safe for you or not. Three eyed fish, etc...

I'm no chemist, but I've got to believe that Lennox wouldn't market a product that could be potentially dangerous.

Anyone have some good info on this?

[airman1]

lennox did a lot of testing before that unit came onboard ...

[teddy bear]

Originally posted by cashcow
I've been researching the Lennox Pure Air system. Accorded to Lennox product data the system produces "Hydroxyl Radicals" to purify the air.

Google "Hydroxyl Radicals" and you get opinions all over the board whether they are safe for you or not. Three eyed fish, etc...

I'm no chemist, but I've got to believe that Lennox wouldn't market a product that could be potentially dangerous.

Anyone have some good info on this?

As large organic molecules are broke down to co2 and h2o, "Hydroxyl Radicals" are an intermideate. Lennox's original presentation stated that 24 hour of constant operation would break down organic compounds to the equivalent of fresh. No mention of the lack of oxygen. This is a slow process. It is no substitute for fresh,filtered air and maintaining <50%RH to provide real indoor air quality. Great marketing!

[pstu]

I have a BA degree in Chemistry from long ago, and am really rusty on most of it. But if I remember correctly radicals are a very unstable form, and they will combine ASAP with something nearby to make a more stable form. In other words radicals would be threatening to human life if there were lots of them around, but there will NOT be lots around because each of them will become a molecule of something else in about a millisecond.

The old adage of "Everything In Moderation" will keep you out of trouble in so many areas, including chemistry. Most of the cases of poisoning involve violating this principle. You don't need to understand the science to follow this adage.

It seems the purpose of the Lennox system will be to change odor molecules into something else so they will not smell. I am not familiar with the safety testing, but am reasonably sure whatever Lennox has done, is enough to prove it safe for adults, children, babies and pets. If there is any Achilles' Heel it will probably be for babies -- not saying there is danger but babies are more sensitive at various stages of growth.

Is this any substitute for air exchange to dilute and remove pollutants? I am thinking the PureAir sounds good for odors but there may be some indoor pollutants which would be better vented outdoors, the sooner the better. But I have not studied the PureAir literature or any reports critical of it.

Interesting topic here. Perhaps I will learn from one of our board Mr. Wizards, or from a report, that I need to change my non-worried attitude. Whether it is cost-effective of course, is another question.

Hope this helps -- P.Student

[Edited by perpetual_student on 05-15-2005 at 11:30 AM]

[strionair]

Oxygen ions are sometimes referred to as “reactive oxygen species” or “oxygen intermediaries”. Unlike ozone O3, oxygen ions are highly unstable and extremely short lived. They quickly react with other molecules or radicals to achieve a stable configuration.

Oxygen ions react with a variety of organic compounds including carbohydrates, proteins and lipids. This reaction is called oxidation--it's the same process that causes iron to rust an apples to brown. Given sufficienct exposure time, oxygen ions can transform organic compounts and destroy a number of cellular tissues, making them an effective germicide. The hydrogen peroxide you pour on a wound disinfects in this manner.

You can learn more about oxygen ions here: http://users.rcn.com/jkimball.ma.ult...ogyPages/R/ROS

[syntropicsystems]

Hydroxyls have an extremely short lifespan - and are difficult to measure. EPA calls them "nature's scrubbers" because they react so quickly with VOCs. More easily measurable are single oxygen molecules, dual oxygen molecules, hydroperoxides, and ions. It's a brave new world of cold plasmas!
RGF Environmental released new photocatalytic technology 2 years ago that is an offshoot of the observations that NASA and their contractors had when researching into closed system air treatments. Remember, you can't bring in outside "fresh" air in space, and filters aren't very effective against microbials. They have posted information on their results - and a good explanation of the process.
Want to significantly reduce your chances of getting sick?
ASHRAE's standards were designed when full indoor air quality measurements weren't possible - and they don't apply in closed systems such as submarines or spaceships. Just because something's written in print doesn't mean we should ignore new findings from smarter people! Lennox didn't sell thousands of units to the Chinese government to combat SARS . . .

[TConnors]

Interesting topic for sure. Looks like ECO-Quest bought RGF Environmental, and ECO-Quest has all kinds of interesting "sounding" products that use "PHI" technology.

http://www.rgf.com/documents/PHI_article.pdf

Seems any one of the units place in the A/C return or in the supply plenum after the coil would "do it all" (get rid of odors, mold, bacteria, every chemical known to man)... why would anyone buy a UV light when they can get one of these gizmos? Just one of those "sounds too good to be true, so it's probably not" products...

My question is, is it really effective if air is blowing by at 1000 CFM? If not placed in or near the HVAC system "all" the house air isn't going through it, so is it really effective? UV doesn't kill anything unless it's within a few inches and exposed for enough time, is this product any different?

[syntropicsystems]

Photocatalytic Oxidation (PCO) doesn't rely on dwell time exposure of the virus or bacteria to the UV light activating the catalyst. It's breaking down the multiple oxygen molecules (o2 and o3) and water molecules (h2o)and recombining them. Bacteria, virus, and fungi (mold) are oxidized by the same actions in outdoor air. Just like our outside atmosphere gets mixed, or a cup of coffee with cream added to it gets mixed, eventually all of the air in the facility gets mixed. It's called Brownian motion.
Placing the RGF technology in the duct treats the ducts and the facility through recirculation, including reduction of mold and bacteria colony forming units on the coils before the air reaches the duct probe. It might take days for the plasma to flow through the entire facility, and additional time for it to work its "magic." Remember, these systems aren't putting out more than .02 ppm ozone or any other unfriendly chemicals. If you have a severe problem that needs immediate attention, you may have to use one of the commercial units designed for unoccuppied usage. They put out a high level of ozone as an additional "kicker" to the PCO reaction (a la EPA 1998 Handbook on Advanced Oxidation.)
Does it work? Bottom line = yes, and you can measure the effects using air sampling, surface sampling, etc. (or just your nose and allergic reaction and odor decrease.)

The technology is "scaleable" - so you can add probes (and reduce) to match contaminant levels (especially if you're dealing with high TVOC situations like smoke filled rooms.)
"Too good to be true?" So were personal computers, microwaves, and solar power. UV lights have been around for a while now, and Einstein identified light acting as a particle and a wave from its effect on metals (catalyst) over 100 years ago. Want to know more about PCO? visit http://www.syntropic.com/APO%20Research%20Articles.htm and take a look at some of the article links.

[TConnors]

I another thread you say: "I do not work for RGF Environmental", yet at your web site your email is ecoquest@syntropic.... Ecoquest being affiliated with RGF. I take it you sell Ecoquest products, and are certainly promoting them here. These products do appear at least as viable as UV lamps, and due to my inability to eliminate DSS, I believe I may try one.

Anything that has a 3 year life, that has no maintanence, and only has a $70-$90 relacement cell cost, seems to be a good value, if it really works, and isn't filling the house with something that causes lung cancer 10 years from now...

From what I've read the best place for these is in the supply duct. Wouldn't just before the coil be more helpful at eliminating any coil bacteria? Would one of the portable units placed in the return be effective, or would my Merv10 filter pull out all that "good stuff" coming from it?

[cob596]

The best unit I have seen is from Kesair ( kesair.com ). It uses UV light and titanium dioxide catalyst. It does not mount in the ducts. You just mount it inside the space ( they have sizes for single rooms or apartments, and larger for houses and commercial spaces.) They seem to have very impressive results, to go with a very impressive price.

[NHMoldInspector]

The reason the Ecoquest RCI cell is far more effective than anyone elses is for two reasons. It has 10x more surface space on the matrix than the PHI cell. Also there is a bonding issue with making TiO2 stick to the matrix and Ecoquest owns the patent to some system of doing so without the usual glue issues that hinder the oxidation process. I love the technology. There is no product on the market with the amount of matrix exposure as the DuctwoRx from Ecoquest...more matrix, means more reactions, plain and simple. However the light does still say RGF on it. Plus, there is a 30 day money back gar so try it, if you don't like it send it back...but you'll like it. It destroys odors...so this is not for the potpouri lover!

The PHI cell is still a wonderful unit, it just has less oxidation.

[syntropicsystems]

It's been awhile since I saw any posts on this thread - so I suppose updates are in order. With PCO it is a combination of the photocatalyst, the light energy activating the photocatalyst, the amount of photocatalyst, and the placement of the photocatalyst with respect to the light. I'm a commercial distributor that attended RGF training as well as multiple EcoQuest commercial trainings, and have probably read more about the physics than anyone else will ever want to know!
The photocatalyst breaks the molecular bonds of water and oxygen molecules using the light energy, turning them into various forms of oxygen. In the case of the RCI cell, most of any O3 (ozone) is broken down to the point where the cells emit less than .02 ppm = far less than atmospheric ground level ozone. Placement is based upon where you want the beneficial oxidation to take place. If you have mold in the ductworks, mounting these units upstream of the mold will eventually deactivate the surface mold, but you still have to deal with the fallout/particulate and the cause of the mold. Generally I recommend putting them in the plenum or the duct - and sizing them for the conditions. If you have a particularly bad environment/room, you may need to spot treat it using a Turbozone in an unoccupied mode.
Putting a cell upstream of a Merv 10 filter shouldn't be a problem. Keep in mind that reflected UV light should not deteriorate the filter, while any direct UV light will usually break the filter down rapidly.
The relatively recently published results are for surface microbials. Don't hesitate to continue using your MERV 7 prefilter and MERV 13 or 14 final filters to keep particulate levels down. The ionization effect of the RCI cells is small. Your level of recirculation, and how much you are controlling the air movement, will certainly influence your overall results.

[NHMoldInspector]

Syntrop, I am a dork and love the technology so I like to know...hehe