The ZANDAIR PCOC™3 (Photocatalytic Oxidation Chamber) model is a powder-coated metal encased unit to be fitted into the HVAC/AHU unit or the air ducting to provide an airtight flow of the airstream through the unit. This model consists of three chambers, each with photocatalytic grids to provide additional dwelling time for maximum breakup of the molecular structure of the VOCs passing in the airstream. The ZANDAIR PCOC™3 has available spaces for an optional/removable MERV-13 (Minimum Efficiency Reporting Value) filter and a Potassium Permanganate Filter (PPF). The PPF is specially formulated to adsorb any ambient formaldehyde / aldehydes. 

PCOC3 view with cover1 pcoc3 chambers

The ZANDAIR PCOC™3 uses Photocatalytic Oxidation (PCO) technology and converts and neutralizes Volatile Organic Compounds (VOC), odors, fumes, and toxic chemicals to benign water and carbon dioxide by-products. The process is called heterogeneous photocatalysis or photocatalytic oxidation. "In chemistry, photocatalysis is the acceleration of a photoreaction in the presence of a catalyst. In catalysed photolysis, light is absorbed by an adsorbed substrate. In photogenerated catalysis, the photocatalytic activity (PCA) depends on the ability of the catalyst to create electron–hole pairs, which generate free radicals (e.g. hydroxyl radicals: •OH) able to undergo secondary reactions. Its practical application was made possible by the discovery of water electrolysis by means of titanium dioxide."[1]

The ZANDAIR PCOC™3 model uses a patented process to affix TiO2 nanoparticles to a solid substrate, for this TiO2 to interact with GERMICIDAL ULTRAVIOLET LIGHT UVC (UVGI) radiation at 253.7 nm which has the advantage that this wave length does not get absorbed by the oxygen molecules, thus does not create any ozone – O3 (trioxygen). Naturally occurring ozone in the ambient atmosphere is converted by the TiO2 / UVC interaction into normal dioxygen (O2) or attached to other ambient gases which hen get converted to benign matter, including diatomic oxygen (O2) which forms 20.9% of our ambient atmosphere.

While the photocatalytic process is very fast, the number of individual photocatalytic actions occurring in the PCO chamber are multiple, sequential, and very complex. The efficiency of this process in our equipment is therefore increased by placing three such PCO chambers sequentially in a single frame, thus increasing the ‘dwelling time’ of the airstream through the ZANDAIR PCOC™3 equipment.

Using a high proportion of return air as part of the airstream (between 85% to 95%) is thus helping in this cleaning process, as the recirculating return air already passed before through this photo-catalytic oxidation process. Recirculation of the airstream is also a very important concept for saving energy as already conditioned for the required room temperature.

A single ZANDAIR PCOC™3 handles up to 2000 CFM airflow. Area to be covered is a function of that volume of air for the intended ACH (Air Changes Per Hour). 6 to 15 ACH recommended. Do not remove any existing HEPA filter. The ZANDAIR PCOC™3 is to be used in conjunction with existing HEPA filter(s). HEPA filtration is still needed for fine particle removal. The ZANDAIR PCOC™3 model is equipment to be permanently installed by professional contractors familiar with air heating and cooling systems. Must be professionally installed to meet all local regulations.


[1]: Wikipedia article on Photocatalysis