Hydroxyl Radicals in Air Purification

This week's post is a first in set of articles designed to inform our readers about the technology behind air purification systems.  This issue's focus is on the photo-catalytic oxidation process used by many Second Wind Air Purifier products.

Second Wind Air Purifier’s preferential approach to Air Purification is to use a process called Photo-Catalytic Oxidation (PCO).  Four components are required to be present for this process to occur.  These are: airflow, a light source, water vapor (humidity) and a catalyst.  The chemical reaction occurs by combining UV (ultraviolet) light with a catalyst, to create a host of "Friendly Oxidizers".  These are oxidizers that are based on oxygen and hydrogen and revert back to harmless carbon dioxide and water after they oxidize.  NO CHEMICALS are involved and therefore NO CHEMICAL RESIDUE REMAINS.  

 The main oxidizer created is the Hydroxyl Radical (OH).  This is a most important oxidizing species.  It is highly reactive and is able to oxidize most chemicals.  This powerful tool has been described as “the detergent of the atmosphere”.  It is the strongest oxidizing process this side of fluorine.  

Relative oxidation power
compared to chlorine.

The same process that creates hydroxyl radicals may also create lower levels of other friendly oxidizers, depending what other hydrocarbons are in the circulating air.  Some of these oxidizers have a longer life-cycle and continue attacking contaminants  as they travel throughout the home, scrubbing the surfaces and breaking down the contaminants they reach. 

The hydroxyl radical lifecycle is short-lived, but it is plenty of time to begin attacking odors, off-gases and pathogens nearby when using Second Wind's technology. Our systems use High Output UV-C lamps and a large catalyst surface area create MORE radicals.  This is essential in understanding and evaluating different air purifiers, .  It is worth noting that the higher the UV intensity and the more surface area of the catalyst you have, the better odor control you will receive.

Second Wind Air Purifier explanation of Photo-Catalytic Oxidation process (sorry, you may have to zoom)

Aside from the whole-home purification that our products provide, there have been other groups working to provide odor control to other parts of the world using this same technology.  A few articles are below.

TiO2 in pavement for improved air quality
Cotton Fabric cleans itself

Turn off Your Second Wind for Thanksgiving Day

For a first post, I am extremely happy to be telling an excellent testimonial story I received from one our awesome Sales Representatives at our National Meeting in Chicago.

  A customer had just installed a Second Wind Model 2000 Air Purifier units just days before the  Thanksgiving holiday.  Family were planning to arrive late afternoon to enjoy some quality time together around the dinner table, where his wife's exquisite turkey dinner with all the trimmings were to be served.
  All the prep work was completed, and the stuffed bird was put in the oven, so the couple decided to take advantage of the beautiful fall day and do some late fall clean-up outside, finishing to protect some young trees, some light raking and such.  All told, it took them out of the house for about 3 hours.
  Upon their re-entry to the house, they entered the front door and the wife froze at the entrance, stunned.  She turned to her husband and yelled, "Oh no! I can't smell the turkey!  The oven's broken or I forgot to turn it on before we went out-everybody's going to be here anytime, the food won't be ready, what are we going to do?"
  After some calming words from her husband, they took off their coats and boots, and walked toward the kitchen.  As they approached, the sweet aroma of the roasting turkey became apparent.  From their initial entry at the front door of the house until they got closer to the kitchen entrance, they could not smell it!
  Second Wind Air Purifiers are equipped to deal with off-gases and odors through a couple of different methods.  Customers are often thankful that the unpleasant smells of smoke, mildew and other obnoxious odors have been removed by our devices, but its not difficult to justify that the good odors we love to endure in our homes are also being treated by the Photo-Catalytic Oxidation Process and they may disappear too!
  So for those of you looking forward to enjoying that sweet, sweet turkey aroma over the holiday, I'd like to suggest that you TURN OFF your Second Wind Air Purifier for the Thanksgiving holiday...Just remember to  TURN IT BACK ON in order to keep purifying your home's air!
  Happy Thanksgiving to all our customers, Sales Representatives and vendors as you celebrate the holiday.